Geology and Mineral Resources of India

visit: grvmalaikalam.blogspot.in GOVERNMENT OF INDIA MISCELLANEOUS PUBLICATION NO. 30, PART-XXII GEOLOGY AND MINERAL RESOURCES OF INDIA 2009 1 visit: grvmalaikalam.blogspot.in GEOLOGICAL SURVEY OF INDIA Miscellaneous Publication No. 30 Part – XXII CONTENTS Page No GEOLOGY OF INDIA 1 1 2 5 5 5 9 10 14 15 19 21 26 27 28 29 32 37 42 43 43 46 47 48 49 50 51 51 54 78 89 130 131 135 137 138 139 140 140 141 COVER PAGE INTRODUCTION PENINSULAR INDIA INTRODUCTION DHARWAR CRATON TRANSITION ZONE SOUTHERN GRANULITE TERRAIN EASTERN GHATS MOBILE BELT EASTERN INDIAN CRATON CENTRAL PRECAMBRIAN SHIELD BASTER CRATON BUNDELKHAND CRATON WESTERN PRECAMBRIAN SHIELD BGC ARAVALLI-DELHI MOBILE BELTS PURANA BASINS GONDWANA BASINS DECCAN TRAP VOLCANISM INDO-GANGETIC-BRAHMAPUTRA PLAIN EXTRA-PENINSULAR INDIA ARUNACHAL HIMALAYA CENOZOIC FORMATIONS QUATERNARY FORMATIONS Andaman Nicobar Islands Lakshwadeep Islands MINERAL RESOURCES OF INDIA Introduction DIAMOND GOLD BASE METALS BARYTE PGE and CHROMITE IRON ORE MANGANESE MOLYBDENUM TIN, TUNGSTEN URANIUM BAUXITE NON-METALLIC and INDUSTRIAL MINERALS 2 visit: grvmalaikalam.blogspot.in Magnesite Limestone Apatite & Rock Phosphate/Phosphatic Nodules Asbestos 141 142 143 144 144 144 145 147 147 148 148 149 Borax Stibnite Fossil Fuel Graphite Ilmenite,Rutile, Monazite and Garnet sands Gypsum Apatite Precious and Semi-precious Stones 3 Tapti and Narmada in the west and Godavari. southernmost tip of the Great Nicobar Island and also the southernmost point of land in the territory of India. Indian sub-continent is tectonically and physiographically divided into three broad domains i. The major plateaus of Peninsular India are the Deccan. Physiographically. Bundelkhand and Chhotanagpur of which Deccan is the largest. The major rivers that originate in Peninsular India are Chambal and Son in the north. all rivers drain into the Bay of Bengal. The east and west coasts meet at the southern tip of Peninsula bordered by the Indian Ocean. Except for Tapti and Narmada which flow westerly into Arabian Sea. The major rivers originating from the great Himalayan mountain ranges are the Indus. the Aravalli Range. the Satpura Range. Himalaya is broadly divided into (i) Siwaliks (ii) Lesser Himalaya (iii) Higher Himalaya and (iv) Tethyan or Trans-Himalaya across its length.blogspot. to little above 370 North and longitudes 68o East to 97o East.e. Damodar in the east.visit: grvmalaikalam. India has a diverse geology with different rock types representing the complete spectrum ranging in age from some of the oldest Archaean metamorphites/granitoids to the youngest Quaternary alluvium. the Peninsular India. Indo-Gangetic plain is sandwiched between the Precambrian rocks of the Peninsular India and the highly deformed suites of the Himalaya of Extra-Peninsular India. 4 . The Indian Republic includes two groups of islands – The Lakshwadeep Islands in Arabian Sea and Andaman Nicobar Islands in the Bay of Bengal. The Himalayan Mountain Ranges-extend for about 2500 km (with an average width of about 240 km) all along the northern borders of the Indian sub-continent from Jammu and Kashmir in the west to Arunachal Pradesh in east-form the Extra-Peninsular Region. the Vindhyan Range and the Eastern Ghats. The Plateau of Peninsular India is surrounded by coastal plains of Arabian Sea on the west and Bay of Bengal to the east.in GEOLOGY OF INDIA INTRODUCTION India extends for about 3200 km from north to south and 2900 km from west to east and is located between latitudes 6o 45′ North at Indira Point. Krishna and Cauvery in the south. The most important mountain ranges of the Peninsula are The Western Ghats (Sahyadri). Ganges and Brahmaputra. the Extra-Peninsular India and the Indo-Gangetic Brahmaputra Plains. Peninsular India is constituted of vast plateaus and mountains. Malwa. central and southern India. The evidences of marine transgression during Mezozoic era are well documented both in the East and West Coasts. PENINSULAR INDIA Peninsular India. Compared to the earlier geological periods. Temporally comparable volcanic events Rajmahal and Sylhet traps along with oldest volcanic event (Panjal traps) are recorded from the eastern and northren part respectively. Remnants of Archaean sialic crust. These Achaean nuclei are later accreted with the fold belt sequence. especially from Himalaya by rivers like Ganges.magmatic episodes. It is preserved only in small isolated basins in Southern.blogspot. These litho packages are developed in faulted graben. However.P. Vindhyan etc. Eastern and North eastern parts of the region. both temporal and spatial development of Quaternary sequences are well documented throughout the country including its coastal tracts.). the most spectacular event of this era is the Deccan volcanism which covers vast tracts of western. Chhattisgarh. Tertiary era is not well represented.Proterozoic) is mainly characterized by the development of major intracratonic basins (namely Cuddapah. However. 5 . Brahmaputra and Indus and has been termed as Indo-Gangetic-Brahmaputra alluvial plain and stretches across northern India from Assam and Bengal in the east through Bihar and U. The middle to upper part of the Proterozoic era (Meso. and display some tectono.to Neo. Godavari.Gondwana rocks spanning between late Paleozoic and Mesozoic period.in The average elevation of the Indo-Gangetic-Brahmaputra plain lying between Peninsular and Extra-Peninsular India 150 m with a low gradient of almost zero level at the Sunderbans Delta of Bengal to about 300 m in the Upper Ganga plain of Punjab. which transgresses well within the Proterozoic. exposes rock units of almost entire spectrum of geological era. to Punjab on the west. central and western parts of the country.visit: grvmalaikalam. INDO – GANGETIC BRAHMAPUTRA PLAIN The tectonic trough sandwiched between peninsular shield in the south and Himalayan Mountains in north formed due to the upliftment of the Himalaya. preserved only in isolated small patches along with the oldest supracrustals are recorded from south. the main repository of economic minerals. has been filled up by the sediments derived from both sides. Indravati. east. comprising Lesser and Higher Himalaya.The foothill Himalaya is overlain by alluvium and separated from the Lesser Himalaya by the north dipping fault commonly known as the Main Boundary Fault (MBF) or the Main Boundary Thrust (MBT) in Garhwal. Murree with the Siwaliks resting on the Proterozoic component of the Indian Shield. It consists of autochthonous late Proterozoic sediments. Bhutan and Arunachal Pradesh Himalaya and known as the Krol Thrust in eastern Himachal Pradesh and Murree Thrust in Jammu area. Precambrian epi-metamorphics and mesograde metasediments.in EXTRA-PENINSULAR REGION The Himalayan mountain chain occurring all along northern part of India can be divided into four contrasting longitudinal litho-cum-morphotectonic belts from south to north. thrust over by three vast nappes that are built up successively of Palaeozoic sediments. Api. Leopargial. The Main Frontal Thrust (MFT) limits the margins of the Siwalik Zone against the Ganga Plains.blogspot. These predominantly fossiliferous sediments range in age from late Proterozoic to Eocene. The foothill Himalaya is a 10. The Indus Shyok belt/the Tethys Himalaya extends to the south of the Trans-Himalayan Karakoram belt and comprises ophiolite mélange (Indus ophiolite and associated formation) and plutonic rocks (Ladakh granitoid complex) of the Indus Shyok belt.to 50.km.The Higher Himalaya marks the region of highest peaks of Himalaya (Nunkun.visit: grvmalaikalam. Everest. Dhaulagiri.wide belt of Miocene to Recent Molasse belt of Siwalik and other foothills comprising the Subathu. The Lesser Himalaya is 60 to 80 km wide and is a discontinuous belt stretching between the MBT in the south and the Main Central Thrust (MCT) in the north. The epi-metamorphic and meso-metamorphic nappes throughout their extent are characterized by early Proterozoic (≈ 1900 Ma) and Early Palaeozoic granitic bodies of large dimension. Kumaon. viz. i) Foot hill belt ii) Main Himalayan belt iii) Indus-Shyok belt and iv) Karakoram belt. represented by sizeable portion of the geological sequences of Proterozoic age with Phanerozoic cover of varying thickness in different parts. Nepal. some of which are Tertiary in age. Nanda Devi. This is followed to the north by Main Himalayan belt. 6 . The MCT separates the Lesser Himalaya from the Higher Himalaya to its north.km. Sporadic occurrence of chromite have been reported from the ultrabasic rocks associated with Dras volcancs from Ophioleite-Melange zone. Badrinath.thick Precambrian crystallines exhumed up and intruded by granites. made up of 10-15. This belt is involved in western syntaxial bend of the Himalaya. Darjeeling. Kedarnath. Kanchanjunga). 2000). Prognastic mineralised sectors are described in detail for future investigation and associated mining.Dharwar. geology of Tertiary and Quaternary Period are not described in detail. This Trans-Himalayan belt lies to the north of the Indus Suture Zone in Ladakh region and extends eastward into Tibet.0 – 3. Deccan Trap and the younger sedimentary basins is discussed below with a brief note on the stratigraphic locales. Some workers believe that the Closepet Granite.. No important mineral occurrence is known from this belt. Eastern Ghats. Drury et al. Singhbhum. which is located ~50 km east of the Chitradurga Boundary Fault represents the boundary between the EDC and WDC (Naqvi and Rogers.. Arabian sea to the west. The Dharwar Craton is divided into two sub-provinces – Eastern Dharwar Craton (EDC) and Western Dharwar Craton (WDC) with Chitradurga Boundary Fault located along the eastern margin of the Chitradurga schist belt as the boundary between them (Swami Nath et al. Gupta et al. 1984.. Satpura. northwest-southeast trending Godavari Graben to the northeast and to the north with Deccan trap cover. DHARWAR CRATON The Dharwar Craton is essentially covered by the States of Karnataka and Andhra Pradesh. 2003.visit: grvmalaikalam. The Dharwar craton is a typical Archaean granite-greenstone terrane with a gneissic basement of tonalite-trondhjemite-granodiorite (TTG) composition known as Peninsular Gneiss. 1976.4 Ga) with minor schist belts of Sargur age (3. 1987. The different tectonic domains as depicted above are enumerated in detail in the following pages with emphasis mainly on the potential mineral occurrences in India. Delhi etc. Aravalli and Bundelkhand several mobile belts like Southen Granulite Teranin. major schist belts of Dharwar age (2. The granitegreenstone terrain exposes rocks older than 2500 Ma. It is bounded by Southern Granulite Terrain (SGT) to the south and Eastern Ghats Mobile Belt (EGMB) to the east.9 – 2.. the northernmost zone comprises Palaeozoic and Mesozoic sedimentary sequences on a metamorphic basement of unknown age.blogspot. Although the actual boundary between the two cratonic blocks remains debatable there are notable differences in lithology and metamorphism of the two blocks. Keeping mineralization aspect in view.3 Ga). Moyen et al.6 Ga) 7 . Gondwana troughs. PENINSULAR INDIA The geology of Peninsular India constituting different Archaean cratons. treated regionwise with major tectonics. 2003). Chadwick et al.0 – 3.. Proterozoic sedimentary basins. The WDC is dominantly occupied by TTG gneisses (3.in Karakoram belt. Bastar. 1980. Meen et al. 1996. marbles and calc-silicate rocks.1992. 1997). serpentinised komatiites. These gneisses contain enclaves of deformed and metamorphosed amphibolitic-and granulitic-grade rocks indicating the existence of an older group of sediments and associated igneous intrusives and are referred to as Sargur Group or ancient supracrustals. The schist belts in the craton are metamorphosed under greenschist to amphibolite facies conditions. staurolite. (ii) banded hornblende-biotite migmatitic gneiss.. The Chitradurga schist belt of Western Karnataka is one of the longest greenstone belts showing several phases of deformation (Radhakrishna and Vaidyanathan.in containing predominant platformal sediments. The profusion of granitoids is responsible for low-pressure high Temperature metamorphism (andalusite-sillimanite type) in the EDC in contrast to the intermediate.pressure regional metamorphism (kyanite-sillimanite type) in the WDC. 2006 and references therein). sillimanite. the EDC is characterised by voluminous late Archaean granitoids (2.. banded iron formation and chromite-bearing ultramafic complexes. The abundance of younger granites in the north and granulites in the south distinguishes the Eastern block as a reactivated zone of mobilized gneisses and granites around the centrally located Archaean nucleus (Western Block).. On the other hand. corundum. These gneisses act as the basement for a widespread belt of schists.1992).75 Ga) (the “Dharwar batholith” of Chadwick et al. (i) a layered and banded complex consisting of quartzofeldspathic biotite gneiss alternating with amphibolites and ultramafic material. 51 – 2..65 Ga (Jayananda et al. 2000) with minor TTG gneisses and thin volcanics-dominated schist belts of Dharwar age.60 to 2. The Western Block of the craton comprises large schist belts (Dharwar type) accumulated in distinct sedimentary basins and the Eastern Block is characterized by voluminous juvenile granites and remobilised gneiss with remnants of schist belts (Kolar type). namely. Peninsular Gneiss-I consists mainly of amphibolite-facies gneisses of tonalitic-trondhjemitic – granodioritic composition (TTG) with four major components. 8 . The lithological types include fuchsite quartzite with layers of chromite and barite. kyanite.visit: grvmalaikalam. cordierite. The southern part of the craton exhibits a transition zone from low. The major part of Dharwar craton is covered by an extensive group of grey gneisses designated as “Peninsular Gneiss” which was further divided into older (Peninsular Gneiss-I) and younger (Peninsular Gneiss-II) based on isotopic age data (Beckinsale et al.blogspot. and a few late Archaean granitoid plutons dated in the range of 2..to high-grade rocks. Nutman et al. (iii) banded migmatitic garnet-bearing paragneiss and (iv) homogeneous trondhjemitic-granitic plutons. biotite schists with garnet. The different units of the Peninsular Gneissic Complex includes three discrete units based on composition. This belt of younger potassic granites mark a major geosuture or joining between two distinct crustal blocks. quartzite. structure and mutual relations viz. Ingladal volcanics. Bellary and Raichur in the east. comprising conglomerates. mostly greywackes in composition and intercalated with cherty iron formation is represented by “Ranibennur Formation”. op. limestone. The end of the Dharwar Cycle is marked by“Closepet Granite” represented by granitic intrusion in a narrow belt 50 km wide. Arsikere and Banawar in the west and Patna. The prominent schist belts of craton in Karnataka are grouped and describe under the Dharwar Supergroup which is divided into two groups-the older Bababudan Group (2.6GA) composed of schistose rocks.blogspot. metabasalt and magnetite rich Banded Iron Formation. Torangal. The youngest series of sediments. 1997). there are other isolated masses of younger granites outcropping away from these linearly disposed granites like those of Chitradurga. western block with a number of welldeveloped low-grade granite-greenstone belts with iron and manganese ores and eastern block marked mainly by younger gneiss of granitic and granodioritic composition enclosing a number of narrow linear bands of auriferous schist belts. representing remobilised parts of an older crust with abundant younger granites and is found in the eastern parts of the Karnataka State. More than 60% of the State of Andhra Pradesh makes up the eastern part of the Dharwar craton and 10% of this cratonic part is covered by rocks of the Proterozoic platformal basins viz. Collision of the two blocks has resulted in the emplacement of granites along the line of junction of the two blocks (Radhakrishna and Vaidyanathan.visit: grvmalaikalam. Overlying this is a more extensive Chitradurga Group(2. 1987). The major part of Andhra Pradesh is covered by“Peninsular Gneiss”.cit). the Cuddapah.8GA) compising orthoquartite. Besides. which occupies the topmost formation within the Chitradurga Group (Radhakrishna and Vaidyanathan. greywacke and associated manganiferous and ferruginous chert.. largely sedimentary in character. In the northern part. (i) gneissic rocks. The supracrustal rocks from Andhra Pradesh occur in the cratonic part and in the marginal zone with marked similarities to the Kolar-type schist belts of the Karnataka State and are composed 9 . different units of the Peninsular Gneiss and the younger K-rich granites are described as the ‘Granitoid-Migmatite Complex’ (Naqvi and Rogers.in Peninsular Gneiss-II is comprised mainly of gneissic rocks with granodioritic and granitic composition. (ii) hornblende-bearing granitoids and (iii) younger granites. Pakhal and Bhima. Sb) (Au. Ag. Li mica) Older Greenstones Kolar Group 3300 – 3000 Ma (Au.in of matabasalt. Zn. Bhima Younger granites Age 1800MA 2000MA 2600 Ma Era PROTEROJIC LATE ARCHAEAN Felsic Complex (Cu) Iron Formation (Au. The Nellore Schist Belt is with Subordinate representation of meta sedminents.Fe. volcanicconglomerate and minor BIF. Three prominent greenstone belts occur in the southern part of the State with discontinuous trace of the belts into the adjoining parts of Karnataka State viz. the third produced broad warps along E-W to ENE-WSW-trending axes. The Dharwar granite-greenstone terrane shows effects of three phases of deformation (Naha et al. Group Cuddapah. (i) the Veligallu – Gadwal belt. (ii) the South Kolar or Bisanattam – Kadiri belt and (iii) the Ramagiri –Penakacherla belt. U) Peninsular Gneiss 3000 Ma (beryl. According to a structural model of the Dharwar craton. the WDC represents a major synclinorium. and major faults and shears parallel to it. Cu. Major Rock Types Kimberlite Puranabasans Maficdyke Potassic granites Greywackes Manganese marker horizon. The terrane is affected by NNW-SSE to NW-SE-trending transcrustal faults/shears which are intersected by major ENE-WSW to E-W and NE-SW-trending faults/lineaments. 1986). As.blogspot. mata-acid volcanics. tantalite. While the earlier two deformations gave rise to the NNW-SSE to NW-SE. Table 1.trending penetrative fabric marked by the general schistosity. while the EDC represents a major anticlinorium.visit: grvmalaikalam. After granate emplacemena the Craton attained rigidity and later magmatic events like mafic dyke activity and Kimberlite activity is along the deep crustal faults/fractures. the limb portion of which is occupied by the Closepet Granite.Mn) Younger Greenstones ARCHAEAN Limestone Mafic volcanics Oligomict conglomerate Mafic – ultramafic rocks Ancient supracrustal rocks Mafic? Felsic rocks (Cu. W) Sargur group Older gneisses 3300 Ma BASE NOT IDENTIFIED 10 ARCHAEAN ARCHAEAN ARCHAEAN . Kaladgi. columbite.. The generalized stratigraphic sequence pertaining to the granite-greenstone terrane of Dharwar craton is shown in Table 1. alkaline and subalkaline plutons close to the western margin of the mobile belt. Magnetite quartzite of the Sargur belt of Karnataka. Recent studies brought to light the existence of Kandra Ophiolite Complex in southern part of Nellore schist belt. Khammam and Nellore. the eastern margin of the Cuddapah basin and the EGMB know as Prakasam Alkaline Province (Leenandam 1980) the locie of igneous activity with the emplacement of anorthosites all along the mobile belt. the MTZ. Narayanpet Kimberlite Field (NKF).visit: grvmalaikalam. As a result. Chitradurga. Raichur and Wynad schist belt of Kerala. iron. which are the locales of deposition of minerals. host rocks for diamonds are distributed in the States of Andhra Pradesh and Karnataka. in the eastern tectonic block of Dharwar Craton (EDC) which was stabilised by ~ 2500 Ma. Sathyamangalam and Wynad) in this region are mainly represented by intercalated sequences of sediments and volcanogenic assemblages. Nuggihalli. the diamondiferous kimberlite/lamproite bodies intrude. Tungabhadra Kimberlite Field (TKF) and Raichur Kimberlite Field (RKF) while lamproites occur in two fields. Gadag. Kimberlites discovered in southern India till now are restricted to the EDC and are distributed in four kimberlite fields. viz. This zone is underlain by Archaean schistose and granitic rocks and was intensely reactivated during the Middle to Late Proterozoic periods. The well-known Kunavaram alkaline complex occurs within 11 . The schistose rocks of the Nellore – Khammam belt. Maski. Wajrakarur Kimberlite Field (WKF). syenite and granite close to the eastern margin of the Cuddapah basin. Within the Peninsular Gneiss and platformal sediments of Proterozoic age. EDC hosts these bodies along or at the intersection of the post-Cuddapah reactivated ENE-WSW and NW-SE fracture / fault systems and / or at the closure of domal structures. Important deposits within these belts are Gold deposit of Kolar. Close to the vicinity of eastern margin of Cuddapah basin a number of granite bodies occur within the schistose rocks of Nellore schist belt. The geological milieu (granite-gneiss of PGC) and tectonic setup favoured emplacement of more than 65 kimberlites and 46 lamproites. Ramadugu and Krishna. Hutti. Ramagiri-Penakacherla. TRANSITION ZONE The Marginal Transitional Zone (MTZ) occurs between the Dharwar craton to the west and the Eastern Ghat Mobile Belt in the east and is made up of granite gneiss and supracrustal rocks. Kimberlites and lamproites. Holenarsipur.blogspot. viz. Gold. trending parallel to the East Coast occupies the transition zone along the eastern margin of the craton. reworked and overprinted by younger deformational events.in The linear belts of oldest supracrustal rocks (Sargur. manganese and titaniferous-vanadiferous magnetite deposits are reported from the schist belts of Gadwal. blogspot. This Proterozoic terrain comprises the northern Periyar-Madurai granulite belt (Chetty. SOUTHERN GRANULITE TERRAIN The Southern Granulite Terrane (SGT) is to the south of the Dharwar craton having a gradational boundary difined by the Fermor Line. a physiographic low. calc-granulites and 12 . charnockitic patches and hornblende-biotite gneisses predominate. In the southern flank of the Palghat gap.1993) with intercalated charnockite (charnockitic massifs of Nilgiri hills. the rocks are predominantly charnockites. quartzites. Achankovil shear zone is another major shear zone exposed in the southern tip of SGT. The SGT is amalgamated to the Proterozoic pandian granulite belt along Palghat-Cauvery shear zone.considered as ancient suture (Gopalakrishnan et al. pelites. Kerala and southern part of Karnataka comprising the Coorg Biligirirangan hills granulite belt of Karnataka in the north and the Nilgiri Madras granulite belt of Tamil Nadu in the south divided by the Moyar shear zone. Within the southern part of the Palghat gap.. also referred to as the Madurai Block (Harris and Santosh. includes sheared charnockitic and migmatitic gneisses intruded by layered anothositic rocks around Bhavani and Sittampundi. The Palghat shear zone is represented by a distinct geomorphic expression. charnockitic gneisses and other gneisses with occasional assemblages of metasediments in the Idukki-Munnar region representing the western continuation of the Madurai block in Tamil Nadu.. 1967). Alkali syenite and related granites also occur outside the province. Other major rock units along the Cauvery shear zone.in the MTZ. 1996. The world famous mica (muscovite) mines at Gudur are located in the Nellore Schist belt. It also consists mainly of high-grade remnants of greenstone belts (Sathyamangalam Group) along with supracrustal enclaves of the mobile belt. The dominant rock types along the shear zone include migmatitic gneisses and banded charnockites. namely. Viswanathan et al. up to the north of the Achankovil shear zone. bounded by Nilgiri hills in the north and Anaimalai and Palni ranges in the south. migmatitic gneisses (hornblende-biotite gneisses) and patches of amphibolites. 1990).. 1996). Yoshida et al. Sporadic lenses of ultrabasic rocks occur within the garnetiferous granitic gneisses. The SGT is mainly exposed in the States of Tamil Nadu. 1990. Kollimalai and Pachchamalai hills along Cauvery shear zone) and metasedimentary (pelitic) sequence and the southern Kerala Khondalite belt. The regional fabric and fold patterns around Kodaikanal and Madurai blocks are abruptly truncated at this zone (Narayanaswamy and Purnalakshmi.visit: grvmalaikalam. Towards the central and the northern parts of the gap. exposes an assemblage of migmatised metasedimentary and meta-igneous rocks (khondalite-charnockite assemblages). The SGT was earlier considered to be the southern extension of the granite-greenstone terrain of Dharwar Craton exposed at a deeper tectonic level. Besides these silica-saturated alkali plutons. these bodies are devoid of carbonatite association and are characterized by pyroxene syenite. Samalpatti and Pakkanadu occur in a NNE-SSW-trending zone extending from Gudiyattam in the north to Bhavani in the south over about 200km. Northern flank of the gap consists of a metasedimentary sequence of khondalite and calc-granulite with crystalline limestone bands. Dharmapuri and Salem Districts. where a number of ultramafic-syenite-carbonatite bodies of Elagiri. constitute the northernmost parts of the State. intruded by acid and alkaline plutons. The southern tip of the Peninsula is represented by the Nagercoil Charnockitic massif (or the Nagercoil block). Minor carbonatites with magnetite have been recorded along the slopes of the Western Ghats near the Kerala border around Kambamettu and Kothagudi in Theni District.blogspot. such as granulites. The alkaline-related plutonism was widespread in the north in parts of Vellore. Several intrusive igneous bodies of distinctive petrological and petrochemical attributes of Proterozoic age occur amidst the granulites. there are two bodies of silica-undersaturated syenite complexes. Geochronological and isotopic studies have brought to light that the southern part of the SGT lying south of Palghat – 13 . Sittampundi. Minor veins of siderite- ankerite-bearing carbonatite with rare sovite types are recorded in the carbonated zone in Attur valley in Salem District. nepheline syenite and corundum syenite. The Salem ultramafic body. Sporadic late Archaean – early Proterozoic granites and associated pegmatites as also Mesozoic-Cenozoic dykes intrude these rocks. Koratti. Thenmudianur. This concept was based on the observation that the grade of metamorphism gradually increases from north to south. Perinthatta anorthosite and Adakkathodu gabbro in Kerala. gneisses and greenstones are preserved.in granites are exposed. Granulites. schists and gneisses. Torappadi. a distinctly charnockitic unit with metasedimentary intercalations. famous for its magnesite deposit is considered to be related to this syenite-carbonatite activity. In contrast to the saturated syenites. south of Achankovil shear zone. granites. Alkaline magmatism is recorded in the form of several syenite-carbonatite bodies.visit: grvmalaikalam. and Mamandur in Tamil Nadu and Ezhimala gabbro-granophyre Complex. Southern part of the State. where major units of the Archaean continental crust. ijolite. The Kerala region is an important segment of the SGT. The time of emplacement of these alkaline plutons has been well constrained by different isotopic systematics. namely the Pikkili and the Sivamalai syenites. . 1995.ultrabasic complex Alkaline complex Alkaline rock Epidote-hornblende gneiss Alkali Complex (Younger) (U. cordierite charnockite Group (with mineral occurrences) Younger Granite (W) Age Era 550-390 Ma 550 Ma PALAEOZOIC to NEOPROTEROZOIC Charnockite (Younger) Gabbro Anorthosite Ultrabasic / basic (Younger) (Mo) Carbonatite. & REE) Basic dyke Basic intrusive 1600 – 2100 Ma MESOPROTEROZOIC Carbonatite and alkaline dyke Syenite complex Ultrabasic complex Alkali Complex (Older) 1900 – 2300 Ma PALAEOPROTEROZOIC 14 700 -600Ma 700 – 900 Ma NEOPROTEROZOIC . granite. Ta. Bartlett et al. These studies have shown that the terrain lying north of PCL shows crustal growth during the period from 3400 to 2500 Ma. 1994). Jayananda et al.. the most pervasive being the 550-Ma Pan-African granulite facies event as constrained by isotopic systematics (Unnikrishnan Warrier et al.. Ghosh et al.blogspot.in Cauvery Lineament (PCL) has a geological history distinctly different from the Dharwar Craton. In contrast. 1994) with the PCL marking the boundary between them.. Y.. grano -phyre & acid intrusive Massive & incipient charnockite.visit: grvmalaikalam. Table 2: SGT Stratigraphy Major Rock Types Alkali granite. In view of the contrasting geological history recorded by the terrains north and south of PCL. This terrain might have witnessed several cycles of metamorphism. Th. Be. crustal growth in the terrain south of PCL is considered to have taken place predominantly during post-Archaean times. as constrained by Nd model ages (Harris et al. 1998). 1995b. The generalised stratigraphic sequence of SGT is shown in Table 2. Nb. the SGT has been divided into the northern Archaean Craton (Dharwar Craton) and the southern Proterozoic (Pandian) Mobile Belt (GSI. 1995. talc-tremolite schist etc. fuchsite-kyanite ferruginous quartzite. Also recorded Base metal mineralization in the Mamandur area of Cuddalore district of Tamil Nadu.blogspot. ARCHAEAN 3200 Ma The SGT is associated with the metallogeny of the metallic minerals. ultrabasic rock Layered ultramafic / mafic. calc-silicate rock. broadly grouped under the categories – Gold mineralization in Archaean greenstone belts of Veppanapalli and Bargur sectors in Krishnagiri district. PGE and chromite mineralization in Archaean ultramaficmafic-anorthosite complexes of Sittampundi and Mettuppalaiyam.Cu.in Older grantie / granitoid Pink migmatite Pink augen gneiss Hornblende gneiss Hornblende-biotite gneiss Garnetiferous quartzo-feldspathic gneiss Garnet-biotite gneiss Migmatite Complex (Peninsular Gneissic Complex II) (Fe) Basic and ultramafic rock Magnetite quartzite Pyroxene granulite Charnockite Charnockite Group 2200–2550 Ma LATE ARCHAEAN TO PROTEROZOIC 2600 Ma LATE ARCHAEAN Calc-granulite Limestone Quartzite Garnet-sillimanite-graphite gneiss Khondalite Group Quartzo-feldspathic rock Amphibolite Banded ferruginous quartzite Kolar Group (Au) 2900 Ma Pink migmatite Granitoid gneiss Fissile hornblende gneiss (Peninsular Gneissic Complex I) (Bhavani Group) 3000 Ma Ultramafic / mafic.Wynad Schist Complex of Kerala (Pb.visit: grvmalaikalam. shear controlled Molybdenum mineralization related to Neoproterozoic magmatism in shear zones.Ag. sillimanite-kyanite-corundummica schist. Banded Iron Formation (BIF) in parts of Dharmapuri. North Arcot. ultrabasic complex (PGE.Cd) BASE NOT KNOWN Amphibolite. Cr) 3000 – 3100Ma Sathyamangalam Group of Tamil Nadu.Villupuram and Salem districts.Zn. basic and ultrabasic rock. Rare metals (U- 15 . This is a typical Proterozoic mobile belt skirting Archaean cratonic blocks and characterized by strong linearity.visit: grvmalaikalam. NW of Eluru. Be) and REE mineralization associated with Neoproterozoic alkaline-carbonatite complexes of northern Tamil Nadu and granites and pegmatites in central Tamil Nadu. Krause et al.. 1981). 1998. 2001). After a gap of about 40 km occupied by the Gondwana sediments of the Godavari graben.in Th-Nb-Ta-Y. also confirmed by deep seismic sounding (Kaila and Bhatia. quartzite. 2000 and Crowe et al. intruded by layered anorthosite and associated mafic and chromiferous ultramafics and alkaline complexes. The EGMB includes two broad litho-stratigraphic groups.The eastern boundary of the EGMB is probably marked by another major lineament along which they abruptly meet the coastal alluvia. Both its northern and western contacts respectively with NOC and Bastar cratons are tectonised. and extends from the southern tip of Orissa to Sambalpur. The Chilka lake anorthosites occur along this lineament. together forming the Eastern Ghats Supergroup. ductile deformation. Madurai district. Broadly EGMB has a NNE-SSW trend in the southern part but changes to NE-SW trend at west of Eluru. pyroxene granulite and leptynites. Age data available from the isotopic studies have provided new insight in to the chronostratigraphy of the events of this Precambrian terrane which range from late Archaean to Pan-African (Sarkar and Paul. on the west. in conformity with the shapes of the Nellore schist belt and the eastern margin of the Cuddapah basin. Tamil Nadu.. 2001. khondalite. extending for over 1000 km covering a distance of more than 600 km of Andhra Pradesh from Ongole in the southern part of the State into Orissa in a northeasterly direction along the eastern coast of the Indian Peninsula. This is a granulite terrain mainly made up of charnockite.. and Tungsten mineralization (Skarn type) in calc-granulites associated with Neoproterozoic granites in the Karungalagudi area. is widest in Orissa (~ 300 km) and covers the major part of southern Orissa.blogspot. the Charnockite and the Khondalite Groups. calcgranulite. The EGMB in Orissa is separated from the Western Orissa Sector by an abrupt geomorphic and geophysical (Bouger gravity) discontinuity. Aftalion et al. high grade of metamorphism and a high gravity gradient along its contact zone with cratons. EASTERN GHATS MOBILE BELT The Dharwar craton is bounded in the northeast by the Eastern Ghats Mobile Belt EGMB). The EGMB has a broad arcuate trend with a westward convexity. the western margin of the EGMB skirts the eastern fringes of the Bastar craton of Madhya 16 . Table 3. The Singhbhum nucleus (Naqvi and Rogers. granitoids. Stratigraphy of EIC (as given in Balasubrahmanyan. also called Singhbhum Shear Zone) in the north. leptynites. variety of dimension stones (commercial granites) using charnockite. EASTERN INDIAN CRATON The Singhbhum-Orissa or Eastern Indian Craton (EIC) comprises Archaean nucleus of South Singhbhum. chrysoberyl. aquamarine. Tertiary and Quaternary formations. EGMB granulites are rich in REE with K-rich alkalies compared to Na. 1987). sapphire. The geology of EIC is detailed in Table 3. The Nellore Schist Belt in the southeast and Khammam Schist Belt in the northeast probably represent the remnants of an originally single N-S-trending schist belt that got dismembered during the development of the EGMB and its subsequent deformation. Rb. ruby. along the East Coast is covered with Gondwana. Sukinda thrust in the south. resources of high-grade graphite and manganese ore and are being exploited locally.in Pradesh. 2006) _________________________________________________________________________ Newer dolerite dykes and sills 1600-950 Ma Mayurbhanj Granite 2100 Ma Gabbro-anorthosite-ultramafics Kolhan Group 2100-2200 Ma -------------------------------------Unconformity--------------------------------------------- 17 . southern part of Jharkhand and northern part of Orissa. These mobile belt granulites (EGMB) have contrasting geochemical attributes than the cratonic granulites of SGT (Subba Rao.visit: grvmalaikalam. This is the richest mineralised cratonic block in India and geographically the EIC comprise western part of the State of West Bengal. 1980). Ba and Th-rich alkalies of SGT. Proterozoic Dalma volcanic belt and the Chotanagpur Gneissic Complex (CGC) in the north. The contact between the cratonic gneisses and the EGMB is a major tectonic feature marked by gabbro-anorthosite and alkaline plutons of Middle Proterozoic age (1600-1000 Ma). a triangular region flanking Bastar Craton in the west. anorthosite and alkaline rocks. occurrences of a variety of gemstones including emerald. high-grade metamorphic Satpura belt in the northwest and Eastern Ghat granulite belt in the southwest. topaz and garnet. This belt is famous for its large resources of bauxite (formed mainly by supergene enrichment of Al from metapelitic protoliths (khondalites).blogspot. is bounded by Copper Thrust Belt (CTB. The eastern margin of the EGMB. local dolomite.000 sq km. IOG constitutes low-grade metasediments including phyllites.ferruginous banded quartzite. 1994). etc. 18 .in Jagannathpur/Malangtoli and Dhanjori-Simlipal lavas.blogspot. banded haematite quartz. The Iron Ore Group (IOG) of rocks (the major supracrustal unit in EIC) deposited subsequent to OMG-OMTG. Enclaves of older rocks like the Older Metamorphic Group (OMG) of igneous and sedimentary rocks now metamorphosed to amphibolite facies (ortho. Nilgiri Granite. iron ore basins in the western sector containing large economic deposits of iron ores. Quartzite-conglomerate (Dhanjori Group) 2300 Ma Pelitic and arenaceous metasediments with mafic sills (Singhbhum Group) 2400-2300 Ma --------------------------------------Unconformity--------------------------------------------Singhbhum Granite III 3100 Ma Epidiorites (intrusives) Iron Ore Group (IOG volcano-sediments) ---------------------------------------Unconformity-------------------------------------------Singhbhum Granite I and II. banded hematite quartz/jasper (BHQ/BHJ)..visit: grvmalaikalam. Bonai Granite 3300 Ma Older metamorphic Group (OMG) and Older Metamorphic Tonalitic Gneiss (OMTG) folding and metamorphism 3500-3400 Ma OMTG 3775 Ma OMG ? 4000 Ma ______________________________________________________________________ A major section of this craton is occupied by the Singhbhum granite batholith complex covering an area of about 10.and para-amphibolite respectively) and the Older Metamorphic Tonalite Gneisses (OMTG) occur as remnants within the batholithic complex. Simlipal-Dhanjori basin comprising volcanics and volcanoclastic sediments. Presence of large number of enclaves of OMGOMTG association occurring throughout the batholithic complex attests to the extensive nature of these rocks before the intrusion of the Singhbhum Granite. iron-ore. The OMTG intrudes synkinematically into the OMG amphibolites indicating that the latter is the oldest unit (Sharma et al. tuffaceous shales. A number of shallow basins (the supracrustals) within and around the periphery of this granite batholith are also present viz. staurolite. the Jagannathpur lava and Malangtoli 19 . Gorumahisani. Kalikapur-Matku. psammites with ultramafics and mafics (gabbro/dolerite) and an upper predominantly volcanic unit comprising mafic ultramafic tuffs. predominantly consists of volcanics and volcanoclastic sediments. resting unconformably over the IOG in the NE part of the craton. A pause in crustal growth followed the intrusion of Singhbhum Granite and was interrupted by a sedimentary cycle (the Singhbhum Group) and a volcano-sedimentary cycle (the Dhanjori Group) respectively. From field evidence. The Dhanjori volcano-sedimentary assemblage is considered to represent a greenstone cycle (Gupta et al. mainly confined to the areas close to CTB. it has been considered that this vast granite batholith can be grouped into three different phases according to their time of emplacement which are as follows: Phase I: Dalima and Rajnagar-Kuyali units. 1964) forming Simlipal hill range. 1985) within the south Singhbhum Proterozoics. The basin comprises spilitic lavas and tuffs along with basal arkose-orthoquartzites and overlies the Archaean basement and two thick inter-trappean orthoquartzite bands. magnetite and chlorite phyllites and epidiorite sills.. Phase II: Besoi. An extensive granite granophyre complex occurring along the western margin of the main Dhanjori basin has obliterated the contact between the Dhanjoris and Archaean Singhbhum granite complex. Another large Proterozoic basin. Gamaria-Khorband-Karanjia units. is a large oval-shaped basin of mafic volcanics. called Simlipal basin (Iyenger and Banerjee. The sequence comprises a lower unit of metapelites. trace. metabasalts and tuffaceous sediments. Saraikela-Jorapokhar-Tiring. extend across the thrust zone to SW of Baharagora over an extensive area up to the base of Simlipal hill range. kyanite-bearing mica schists with numerous bands of quartzites and ortho. intrusives.in acid intermediate and mafic volcanics as well as mafic sill-like intrusives. The Singhbhum Group metasedimentaries. Majumder. This is followed by Dhalbhum Formation at the top containing phyllites with a few quartzite bands. chlorite.and parahornblende schist. Vast copper deposit within the low-grade metavolcanic member has been extensively mined. 1996).blogspot. REE and isotope geochemistry (Saha. Hatgamaria and Keonjhargarh-Bhaunra units and Phase III: Haludpukur-Chapra.Two other large volcanic suites were formed during this period namely. Deposition of IOG is followed by intrusion of Singhbhum granite batholith representing dominant crustal growth in this craton.The lower ultramafics have distinct komatiitic affinity with definitive spinifex textures (found only within this unit of EIC.visit: grvmalaikalam. Towards the top. Singhbhum Group starts with the Chaibasa Formation containing garnet. The Dhanjori basin. the Singhbhum Group is terminated with the eruption of Dalma volcanics.The upper Dhanjori basaltic suite comprises alkali olivine basalts passing upwards into K-poor oceanic tholeiites. 1994). shale. lying north of CTB and sandwiched between the Singhbhum nucleus in south and high-grade CGC in the north. is a 200-km-long and 3-7-km-wide arcuate belt and mainly comprises greenschist facies rocks of Singhbhum Group and meta-volcanics. etc. 1994).The belt has been intensely folded into a synclinorium along E-W to NE-SW axes which is refolded at the eastern and western extremities (Saha. shale. however. Dalma volcanics bear considerable similarity with Dhanjori volcanics. 1994). pyroxenites) of considerable dimensions are also found interlayered with the tuffaceous horizons in the eastern sector. lavas and vitric tuffs with quench textures. quartzites. argillaceous limestone and orthoquartzite. chlorite schist.blogspot. The sediments are sandstone. volcanoclastics. Compositionally these lavas display three distinct types viz. The Proterozoic volcano-sedimentary cycle is followed by intrusions of large isolated granitoid bodies like Kuilapal and Chakradharpur granites (CKPG) in the NE and southern margin of Dalma belt respectively. The lower member comprises of phyllites (often carbonaceous). 1994). low-grade metabasalts. The MBG was overlain by the Kolhan Group of sediments. 1984). The final stabilisation of this craton is marked by the intrusion of spectacular set of reticulating basic dyke swarm. high-magnesian komatiitic serpentinised peridotites. there was a pause followed by the final crust forming events in this area beginning with the emplacement of gabbro-anorthosite complex along the eastern margin of Singhbhum granite batholith extending from Butgora in the north to Nausahi in the south. The CKPG is an east-westtrending elongated body with numerous enclaves of amphibolites.These two lava formations are considered as post-Singhbhum granite and pre-Kolhan age (Saha. Dhanjori have always been considered as either equivalent to Dalma or slightly older. The upper Dalma member is represented by high iron . The Proterozoic Dalma belt. talc-schist. This is followed by emplacement of Mayurbhanj Granite (MBG) covering approximatly 1000 sq km (Saha. intruded along the southern margin of CTB. rootless intercalations of arkose-conglomerate and quartzite (Bhaumik and Basu. are the soda granite and the Arkasani granophyre. The Kuilapal granite is an ellipsoidal granite gneiss body occurring within moderately high-grade metamorphosed pelitic schist and interbanded hornblende schist. Stratigraphically. Its composition varies from trondhjemite to tonalite.in lava. Concordant basic-ultrabasic plutonic bodies (gabbro. Other acid plutons. though the former contains less basaltic komatiites. mainly confined in the 20 .low potash tholeiitic basalts along with some rhyolites. After the relatively minor Proterozoic crust building episode within the Dalma belt.visit: grvmalaikalam. Stratigraphically. known as Newer dolerite dyke swarm (NDD). the rocks of this belt are classsified into a lower and upper member. metaandesite and meta-oligoclase andesite. talc schist and conglomerate. copper.in southern part of CTB.e major part of Maharashtra and Western part of Madhyapradesh) The SCP is with Archien nuclei known as Bastor Craton. mica and manganese in the carbonate-rich mobile belt of Gangpur-Chotanagpur and granite plutons with associated pegmatites and quartz veins carrying beryllium. The Western part of thei sector is blanketed by thick pile of Deccan Traps (i. tungsten. plutonic and sedimentary rocks to a gneiss-granulite-granite association. uranium and tantalum. phosphorite. to the North 21 . The Baster Craton is bounded to the North East by Mahanadi graben. occurrences of lead-copper. The northern limits of the Meghalaya uplands are marked by the Brahmaputra Plain.The various rock groups occupying the region includes Bomdila Group. The major parts of CGC occurring in south Bihar and northern part of Jharkhand and in West Bengal is a vast gneissic terrain exposing complex assemblages of diversified rocks. forms an integral segment of the Precambrian Continental Shield of Eastern India. Nongpoh and Mylliem. niobium. Jaduguda uranium mineralization. basement gneisses of Meghalaya Plateau and granitoids of EIC like Kyrdem. lithium. metamorphism. The Chhotanagpur Gneiss Complex (CGC). Birbhum and Medinipur of West Bengal in the east. iron. sedimentation. of the South West by Godawari graben. Bankura. tin. This part of the Peninsular Indian Shield is associated with the mineralization of copper in Mosabani-Bedi –Rakha mines in Jharkhand.visit: grvmalaikalam. partial melting and mineralisation that have altered the pre-existing volcanic. which have witnessed several periods of magmatism. chromium. the Southern Crustal Province (SCP) and Northern Crustal Province (NCP) separated by a prominent East -West trending Central Indian Shear (CIS)/ Central Indian Tectonic Zone (CITZ). 1942). the Meghalaya is a huge geomorphic up-arch of Precambrian metamorphic rocks with a narrow southern fringe. tin.gold. vanadium. tectonism. In northeast India. manganese. beryllium occurrences in late Proterozoic granitesyenite-gabbroic province in western Orissa.cit) in EIC. Sung Valley alkaline carbonatite complex. extending from Chhattisgarh in the west through Orissa and Jharkhand up to parts of the districts of Purulia. molybdenum in the mafic magmatic provinces in Jharkhand and north Orissa. The Chhotanagpur Granite Gneiss Complex (CGC) occupies a considerable area in the northern part of EIC and is intrusive into the schists in the south (Dunn and Dey. CENTRAL INDIAN PRECAMBRIAN SHIELD The Central Indian Shield is a mosaic of two crustal provinces. titanium. NDD is considered to be the youngest magmatic activity and stratigraphic unit (op.blogspot. gneiss. Acharyya and Roy. 1990. Tirodi Gneiss Sonakhan. Abujhmar Volcanics. Nandgaon Group. Cholanguda granite (Sn – W mineralization) Bundelkhand Granite. Pakhal and Sullavai Groups constituting important Purana cover sedimentary sequences. 2000). Bhopalpatanam Granalite Belt is seen to shoulder along the Godawari Graben. as Tirodi Gneiss (Sausar Group) Majhgaon. Keskal granite.The Abujhmar Group is a volcano-sedimentary ensemble in contrast to Chhattisgarh. Chilpi Ghat. The Bundelkhand Craton (BDC) in the north and the Bastar Craton (BC) in the south have Archaean nuclei. 1986.in Weas by Satpura Mobile Belt and to the South East by Easternghats Mobile Belts. granite.. The supracrustal belts in northern and western parts include the Mahakohal. Chilpi Group. Bailadila. surrounded by the Vindhyans and the fold belts of AravalliDelhi in Rajasthan. Indravati. PaliamDarba. Khairagarh.blogspot. whereas to the south and east the Sukma. Chilpi Groups Sukma. Pujariguda. Abhujmar Group. Malanjkhand tonalite-granodiorite Gneiss. Burgudem.gneiss Granite Granite. To the south. (?) Sakoli. Khairagarh. Deccan Protocontinent (DP) or the SCP occurs with the Singhbhum-Bastar-Dharwar Cratons (Yedeker. volcanics Group Khairagarh Belt. Yedeker et al. 1990) Major Rock Types Supracrustal rocks.. Amgaon Gneiss.visit: grvmalaikalam. Sakoli. The domain to north of the SonNarmada-Tapti (SONATA) lineament is named as the Bundelkhand Protocontinent (BP) or the NCP consisting of the Bundelkhand craton. granite and gneiss Kimberlites Mafic dykes. Sausar. Age 800 Ma 1200-1000 Ma Era NEOPROTEROZOIC NEOPROTEROZOIC to MESO- 1500 Ma MESOPROTEROZOIC 1600 Ma 1600 Ma MESOPROTEROZOIC 2200 Ma PALAEOPROTEROZOIC PROTEROZOIC 2400-2300 Ma 22 To . Bengpal and Bailadila Groups form the main lithotectonic associations. Dongargarh Granite. Sausar Group. Hinota diatremes Mafic dykes and granite in Bastar craton. Granite in Satpura Belt. The simplified stratigraphy of Central Indian Precambrian Shield (CIPS) is given in Table 4. Table 4: Stratigraphy of CIPS (simplified after Sarkar et al. Gwalior. Sausar Groups apart from the Dongargarh Supergroup. Bailadila Group. to the southwest by the Pranhita-Godavari graben. and to the southeast by Eastern Ghats Mobile Belt. Sukma Group comprises slivers of quartzite.3 Ga). pelites. 1990).1 Ga). consisting of quartzite. charnockitic suite of rocks along the Wainganga valley in Bhandara and Chandrapur districts.5Ga) followed by the (i) Sukma metamorphic suite (≈ 2.Dutta et al. Baya and Sukma Gneiss LATE ARCHAEAN 2600-2500 Ma LATE ARCHAEAN ARCHAEAN ? 3600 Ma ARCHAEAN BASTAR CRATON The Bastar Craton (BC) is bounded to the northeast by Mahanadi graben. Indravati. quartzite. Bengpal Group (≈2.visit: grvmalaikalam. calc-silicates. and (v) the cover sequence of the Chhattisgarh.Godavari valley. Sukma Groups Bundelkhand. (1981) indicate a Narainpur Group above the Bailadila Group with sandstone.6 Ga). The cratonic components of Bastar includes Basement Gneiss (≈ 3. the 23 Tirodi gneisses of Nagpur-Seoni area . Sausar and Betul-Chhindwara belts and the granulites in Sausar terrain. the gneisses and associated supracrustals of Bastar area. (ii) Bundelkand gneiss-granitoid terrain with enclaves of minor supracrustal belts. The NCP includes (i) The Central Indian Tectonic Zone with gneiss.blogspot. conglomerate and andalusite and chloritoid schist. and (?) Sakoli Groups Gneiss Metasediments Gneissic Complex Bengpal. BIF and amphibolites.supracrustal-granite litho-associations of Mahakoshal. the Dongargarh granite and younger Khairagarh Group of volcanosedimentary sequence. (iii) Kotri-Dongargarh belt of volcanosedimentary-granite association of Dongargarh Supergroup is represented by older Nandgaon Group of basic and acid lava and pyroclastics. undifferentiated granites and basic dykes (Ramakrishnan. conglomerate and mafic volcanics. and (iii) Cover sequences of Vindhyan and Bijawar Supergroup /Group. hosts iron-rich deposits. (ii) Sonakhan belt is endowed with greenstone-granitoid association. Amgaon. The Bengpal Group of rocks consists of low-to medium-grade volcanosedimentary sequence of amygdular metabasalt. Bailadila Group (2.5 Ga. phyllite and BIF. Albaka and Sullavai Supergroup / Group. pelitics and quartzite laid on Amgaon Gneisses of 2. This includes gneissic rocks of Pranhita.in Mahakoshal Group Abujhmar. to the northwest by Satpura mobile belt. (iv) Sakoli belt comprises distinct low-grade supracrustrals of bimodal volcanics. Nandgaon. Archaean gneisses and high-grade granulitic/charnockitic rocks are exposed mainly in the southern part of the region. visit: grvmalaikalam. 1958). The Sonakhan Group of rocks occurs in the eastern part of Chhattisgarh State. Bijli consists mainly of rhyolite and sandstone.blogspot. This belt is about 200km X 60km2 and further southward merges with the gneissic country of Bastar area where these have been named as Bengpal (Sukma) Gneiss-supracrustals. and commonly contain minor amounts of graphite.pelite) and meta-igneous (amphibolite.1962).735) with mineral ages of 2050 Ma and 1620 Ma. calcareous and ferruginous. They show gradational contact with BIF and calc-silicates rocks. gneisses and supra crustals occurring to the east of Sakoli basin in GondiaBhandara. The rocks are well exposed in the eastern part of Bhandara district in 24 . ultramafic) litho-types.Rajnandgaon sector grouped as Amgaon Group (Sarkar. at times micaceous. basalt-rhyolite association of volcanics with greywackes and conglomerates.6 Ga. Pitepani volcanics mainly includes massive to porphyritic basalt with rare pillow structure. meta-igneous and TTG restites. Gneiss migmatites include banded gneiss. Chandrapur. The gneisses exposed south of Sakoli fold belt in Gadchiroli. the whole setup being dismembered by younger granitic intrusives in different areas of the region. Nagpur and Bhandara districts are generally referred as Bengpal Gneisses. The Bastar/Amgaon/Tirodi gneisses and associated supracrustals include upper amphibolite facies. high-grade gneiss-migmatite with supracrustals including metasediments (quartzite – BIF – carbonate . Magnetite – specularite form BMQ (BIF) with impersistent folded quartz-magnetite banding on milimetre to centimetre scale extending for several kilometres and contains 67 to 68 % Fe. hornblende schists.in (Narayanswamy. Quartzite bands of Bailadila Group extend along strike for several kilometres in the southern parts of Gadchiroli District and are interbanded with other meta-sedimentary rocks. quartzite and pelitic schists occurring as thin bands are scattered over a wide area. The maximum age for Bengpal Group of rocks is set by the intrusive Paliam and Darba granites with whole-rock isochron age at 2308± 48 Ma (Sri = 0. stromatic gneiss and leucocratic gneiss containing meta-sedimentary. The supracrustals are interleaved with gneissic rocks that contain relicts of TTG suite. Quartzites include orthoquartzites. The Nandgaon Group comprises Bijli volcanics and Pitepani basic volcanics. Banded magnetite quartzite. Two such important patches are seen in parts of Chhattisgarh. The quartz veins in the bimodal volcanics are gold-bearing. Towards eastern part it is designated as Baya Gneiss. This comprises continental bimodal. The closing of the Sukma Orogeny is indicated by the Sukma granite gneiss at ≈ 2. pyroxene-bearing gneisses. metabasalts. possibly a variant of banded manganiferous iron formation) are the other significant rocks of this group. The southern periphery of the supracrustal sequence reveals linear suite of two-pyroxene granulite-charnockitemetapelite granulite lenses and pods. The 75-km-wide and 300-km-long Sausar Fold Belt in Madhya Pradesh is trending E-W. Both mafic and felsic volcanic rocks are present in nearly equal proportions. 25 . The Sakoli Group covering an area of about 3500 sq km in parts of Nagpur. and (iii) Sausar Group comprising calcsilicate gneiss. metarhyolites and banded iron formation (BIF). Tirodi Gneiss and the Augen Gneiss. is now related to a granulite-facies metamorphism in Ramakona – Katangi granulite belt preceding the deposition of the supracrustals. It is confined between the northern Bundelkhand Protocontinent and the south Deccan / Bhandara Protocontinent. calcite marble. The Sausar Mobile Belt (SMB) displays the Sausar Group together with some granulites. Quartztourmaline rock (tourmalinite) and banded garnet-amphibole-biotite-quartz rock (BGA. The main Sausar Orogeny is ≈ 1000-Ma Grenvillian age implying granulite metamorphism as pre-Grenvillian. foliated granite. exposing a central domain of dominantly supracrustal rocks (metamorphosed quartzite. This Proterozoic major crustal belt is said to have three lithotectonic units – (i) Mafic granulite-felsic migmatite gneiss – the Tirodi biotite Gneiss.in Salekasa area and extend southwards in Korchi area of Gadchiroli district and in parts of Rajnandgaon district of Chhattisgarh. alkali-feldspar granite. Quartz veins.1963). chloritoid. The granulites reveal the pre-Sausar structure (Narayanaswami et al. The volcanic to sedimentary rocks ratio is about 1:4. dolomite marble and quartzite (Bhowmik et al. Bhandara and Gadchiroli districts of the Maharashtra comprises a metamorphosed volcano. garnet and staurolite). pelites and carbonates) and characterized by lack of volcanic rocks. 1986).visit: grvmalaikalam. The Tirodi biotite Gneiss considered earlier to be a migmatised Sausar supracrustal unit. It is intimately associated with a variety of granitic rocks of anatectic origin.. (ii) Augen Gneiss.. The Tirodi Gneiss indicates an age of 1525 ± 70 Ma with a mineral isochron at 860 Ma (Sarkar et al.blogspot. Sakoli Group includes metasediments dominated by phyllite (carbonaceous at places).. curvilinear (southerly convex) belt extending from Balaghat in the east to Chindwara in the west. The gneiss and older supracrustals (Sukma-Amgaon) encircling the Sakoli Group represent basement to the Sakoli sequence and also occur as inliers within the Sakoli Fold Belt. tuffs and flows with composition ranging from rhyolite to rhyodacite. The meta-basalt are iron-rich tholeiite while meta-rhyolite are represented by pyroclastics.sedimentary sequence. 1999). andalusite. pegmatite and amphibolite/gabbro are the intrusives in the Sakoli Group. mica schist (with varying proportions of magnetite. This has quartzite. 1990. which unconformably overlies the volcanic rocks of Nandgaon Group and the Dongargarh Granite. south of Mahakoshal Belt and intruded by gabbro-anorthosite and granite are thought to represent granulite metamorphism at ≈ 1. The Bortalao Formation forms the lowermost litho-sequence of the Khairagarh Group. The lower Agori Formation consists of pillow-pahoehoe toes. In the northern part of this belt peridotite. The Dongargarh Supergroup occurs to the west of Chhattisgarh basin and to the east of Sakoli synclinorium. 2003). The Mahakoshal Group is a supracrustal sequence with dominant metasediments and subordinate tholeiite metavolcanics with intrusive dunite-peridotite and occasional sills of sodagranite. The contact of this group with the Jungel Group is also faulted. pyroxenite. ultramafic and granitic rocks with bimodal volcanics – a low K-tholeiitic basalt and calc-alkaline to alkaline rhyolite. The Betul supracrustal belt is a granitoid gneiss tract between Mahakoshal Belt to the north and the Sausar supracrustal belt in the south. garnet-anthophyllite schist intruded by mafic. Roy and Prasad.blogspot. pelite. It forms an E-Wtrending belt of varying width on the flanks of normal and inverted canoe-shaped folds and saddle folds in the area south and west of Deori and NNE-SSW-trending limb of syncline in east of 26 . calc-silicate. The group has a faulted contact with the Archaean gneisses and migmatites between Jabalpur and Sidhi comprising the Agori and Parsoi Formations in which intrusives occur. BIF. This group overlies Amgaon and Sakoli Groups. norite and diorite have BIF granulite enclaves. gabbro.Three phases of folding with amphibolite-facies grade of metamorphism and intrusion of granite are noted.visit: grvmalaikalam.7 Ga (Pichai Muthu. The contact with the Vindhyan Supergroup lying above is also faulted. comprising the lower igneous suite of Nandgaon Group and upper sedimentary igneous alternation of Khairagarh Group separated by a pronounced unconformity subsequent to the emplacement of the Dongargarh Granite. Volcano-sedimentary sequences of the Khairagarh and Abujhmar groups and sediments of Chilpi Group belonging to Palaeo-Mesoproterozoic unconformably overlie the older sequences and the granite in the Mailkala range and Abujhmar plateau region. Platformal cover sequence of the Chhattisgarh Supergroup of Meso-Neoproterozoic occupies the Chhattisgarh plains. The Khairagarh Group is exposed in the central part of the Dongargarh Belt south of Deori and around Darekasa of Maharashtra and in Rajnandgaon district of Chhattisgarh state. volcanic breccia. bomb agglomerate. Pakhal Supergroup belonging to Mesoproterozoic occupies the Godavari valley region. This group of rocks occurs as a horst in the Satpura axis.in The Makrohar granulites occurring as a belt to the south of the Son-Narmada South Fault (SNSF). tuff and chert. which are correlatable with the Dongargarh Granite. basalt and andesite in a fine-grained matrix. 27 . chlorite schist. and this lithounit is considered by Yedekar and Jain (1996) as intraformational between Mangikhuta and Kotima Formations. The BIF includes carbonate-and sulphide-bearing bands. which include N-S-trending Darekasa Fault (Sarkar. exposed in several batholiths and stocks parts of Bhandara and Gadchiroli districts of Maharashtra and Rajnandgaon district of Chhattisgarh States. cobbles and boulders of variously coloured Bijli rhyolites. trachyte. located in the southern and northern part of the triangular belt with Sakoli. arkose. chert. Mahla Formation and Rhyolite Formation represent the Nandgaon Group of Dongargarh supergroup in the Kotri Belt. It is followed by the Mangikhuta volcanics consisting of non-porphyritic. The meta-ultramafics show alteration of original pyroxene to an assemblage of serpentinite-tremolite and tremolite-serpentinite-actinolite. amygdaloidal pyroxene tholeiite with minor intertrappean. The Kotri Belt is the southern extension of the Dongargarh belt with comparable stratigraphy.blogspot. The intrusives within the belt are coarse pink granites. The Amgaon Gneiss. dated at ≈ 2. Impersistent beds of conglomerate often occur at the base of this formation consisting of well-rounded pebbles.in Salekasa. Karutola Formation disconformably overlies the Sitagota volcanics and consists of fine-to coarse-grained.4 Ga. often being pyritiferous. equigranular and microgranite textures and devoid of pegmatites.visit: grvmalaikalam. Several major faults have been recorded mostly affecting the lithounits of the Khairagarh Group. The isotopic age data points to a temporal association among Malanjkhand granodiorite. The Abujhmar Group in the Kotri Belt is correlatable with Khairagarh Group. laminated shale and siltstone. 1957-58). This granite. muscovite schist and sericite quartzite associated with meta-ultramafic and gabbro bodies. Quartzite includes conglomeratic bands of local importance. Ghogra Sandstone is mainly quartz-arenite in composition. Dongargarh granite. The Sitagota volcanics overlie this and comprise dull green basalt with minor tuffs and agglomerates. The belt occurs in northwestern part of the Gadchiroli district of Maharashtra and partly in adjoining parts of Chhattisgarh and includes a litho-assemblage of locally significant conglomerate. is intruded by the Dongargarh quartz monzonite and Malanjkhand granodiorite. Dhara-Kamarwara and Tappa faults also extend in N-S direction for tens of kilometres at the eastern margin of the Khairagarh Group. Sausar and Dongargarh supracrustals and granulite belts. quartzite. vein quartz. known as Dongargarh Granite. is one of the oldest rapakivi epizonal coarse-grained granite with porphyritic. well-bedded pure and ferruginous quartzites. Kimberlites occur as intrusives into Bastar craton. The Bundelkhand Granite consists of an early porphyritic phase followed by several intrusive phases of monzonite. uranium mineralization in a 100-km-long shear zone in crystalline rocks from River Mahan in the west of Surguja district of Madhya Pradesh 28 . biotite. the SonNarmada North Fault of Central Indian Tectonic Zone to its south. Bundelkhand Granite has been isotopically dated at ≈ 3.early Proterozoic cratonisation in this part of the shield area (Ramachandra. Large-scale granitoid magmatism of batholithic dimension around 2. This cratonic area comprises ultramafics.and leuco granitoids.visit: grvmalaikalam. acid volcanics. 1998). amphibolite. stratiform zinc sulphide mineralization at Kholari-Bhaonri in the lower part of Bhiwapur Formation and vein type copper-galena-gold-tungsten mineralization with platinum incidence at Kholari-BhaonriRanbori and Ranmangli areas in the upper part of the Bhiwapur Formation of Sakoli Group.blogspot.000 km2 bounded by the Great Boundary Fault to its west. marble. Other mineralisation in this part of the shield area includes the Malanjkhand copper in granodiorite. calc-silicate rocks and tonalite-trondhjemite-granodiorite (TTG) intruded by undeformed hornblende-. schists. diorite-syenite-granite and other porphyries with three generations of dolerites. banded iron formation. It is emplaced between older Nandgaon Group and younger Khairagarh Group. workable Khobna tungsten prospect of Umrer Tehsil of Nagpur district. Dykes of porphyry. 1994. rhyolite breccia and pegmatite veins pervade the massif. Malanjkhand Granite) in the Central Indian Shield probably reflects the late archaean . fuchsite quartzite. leucogranite.3 Ga. Maharashtra State hosted by the quartz-chlorite mica schist of the Sakoli Group. occurrences of manganese ores associated with ‘Gondites’ of Sausar Group.in Bijli rhyolite and Dongargarh granite. BUNDELKHAND CRATON This highly deformed granite-greenstone terrain consists of the Bundelkhand Granite massif with an aerial extent of 26. Ramachandra and Roy. Ganga Foreland to its north and wrapped around by the extensive Vindhyan Basin.2 Ga (Bundelkhand Granite. The NE quartz reefs and NW swarm of mafic dykes terminate the activity in this massif. Dongargarh Granite. skarn type of tungsten (scheelite) occurrences along with minor sulphides of base metals in amphibolite within tourmaline granite at Umrer and in marble/calcareous quartzite at Kosamtondi-Bagarban-Kheripur areas. alkali granite and granodiorite in the Mahakoshal Group hosting copper mineralisation at Karaudiya in tholeiitic metabasalts.5-2. minor gold-silver-tin-molybdenum occurrences in BIF of Sakoli Group. Pur-Banera Jahazpur Groups and Sawar Group Hindoli Group..visit: grvmalaikalam. Salumbar. Mangalwar Complex and Sandmata Complex Mafic and ultramafics. Table 5: Stratigraphy of Western Indian Precambrian Shield (after Gupta et al.in extending to the east in Palamau district of Jharkhand State and uranium deposits in metarhyolite and metabasics in periphery or close to the Dongargarh Granite at Bodal and Bhandaritola. Laterite with pockets of bauxite forms capping at a number of places over these rocks in Keshkal-Amabera area. fluorite occurrences within sheared Dongargarh Granite at Chandidongri.blogspot. Untala and Gingla Granites Supergroup Age Era 1600 – 700 Ma NEOPROTEROZOIC Delhi Supergroup 2000-1600 Ma MESOPROTEROZOIC Aravalli Supergroup 2500-2000 Ma PALAEOPROTEROZOIC Bhilwara Supergroup ≥ 2500 Ma 29 ARCHAEAN . The stratigraphy of the area is summarized in Table 5. 1980) Major Rock Types / Group Erinpura Granite Malani Volcanics Godhra Granite and Gneisses Punagarh and Sindreth Groups Sendra-Ambaji Granites Kishengarh Syenite Phulad Ophiolite Suite Kumbhalgarh and Ajabgarh Groups Gogunda and Alwar Groups Champaner Group Lunavada Group (Udaipur. Udaisagar and Darwal Granites) Rakhabdev Ultramafic Suite Jharol Group and Dovda Group Nathdwara Group Bari Lake and Kankroli Groups Udaipur Group Debari group Undifferentiated Granite Ranthambor Group Berach and Jahazpur Granites Rajpura-Dariba. WESTERN INDIAN PRECAMBRIAN SHIELD The Precambrian of the Western Indian Shield from east to west comprises the Banded Gneissic Complex (BGC) or craton and the Aravalli – Delhi mobile belts with the TransAravalli basins encompassing the area west of the Aravalli mountains. Amet Granite. 1953. leptynite and norite dykes. 1992). The volcanic component is represented by basic lavas now occurring as hornblende schist or amphibolite (Heron. (2) the Mangalwar Complex which is subdivided into the Lasaria. The BGC was later on reclassified as the Bhilwara Supergroup comprising (1) the Sandmata Complex which is subdivided into three formations viz. Potla and Rajmahal Formations. epidiorite and quartzite.in BGC The oldest cratonic nucleus of the Western Indian Shield. Suwana. The BGC is a time transgressive crystalline complex.. the BGC. occupies a large tract in the Mewar plains of south and east Rajasthan. The older component of the Aravalli craton occurs in the BGC in the eastern and southeastern parts of the Aravalli Range.gneiss. Metamorphic and structural studies have clearly demonstrated that the BGC was the crystalline basement over which Proterozoic rocks of Aravalli and Delhi Supergroups were deposited. and mafic igneous suite of rocks. and Hindoli Group in Gupta et al. Sarara. amphibolite. 2000). The Deccan Traps delimit the southern boundary of its outcrop area (Gupta and Malhotra. the Baranch. 1981) and Vindhyan platformal sediments demarcate the eastern boundary of this craton. 1991. The Sandmata Complex comprises migmatite. Badnor and Shambhugarh Formations. Roy. Mando Ki Pal. cordierite-garnet pelitic gneiss. basic granulite. Kekri. Eastern Aravalli belt in Gupta. garnet-sillimanite gneiss. and (3) the Hindoli Group which is subdivided into the Bhadesar. Sujanpura and Nangauli Formations. calc. It is bounded on the west and southwest by Proterozoic fold belts of the Aravalli and Delhi Supergroups. 30 .. and intruded by Gyangarh-Asind Charnockite-enderbite.. garnet-staurolite-sillimanite schist. hornblende schist. Sinha Roy. comprising gneisses of amphibolite to granulite facies derived from plutonic.visit: grvmalaikalam. 1934. composite gneiss/bimodal gneiss. The metamorphic-cum- migmatitic contact between the Sandmata Complex and the Mangalwar Complex practically coincides with the Delwara lineament. while an arcuate belt of low-grade volcanometasedimentaries (Gwalior Series in Heron.1988. etc. The crystallines are intruded by granitic plutons of several generations ranging in age from Archaean to Middle Proterozoic.blogspot. mica schist. pyroxene granulite. with the absence of charnockite and eclogite but the presence of high-alumina granite. norite. 1953. chlorite-biotite schist. 1985 and Sinha Roy et al. enderbite charnockite. Anjana Granite. The complex is further characterized by preponderance of acid. The term Sandmata Complex is restricted to the ductile shear zone bounded by granulite-facies rocks. The sedimentary component is dominantly pelitic and is well exposed on the eastern margin of the Delhi Supergroup. volcanic and sedimentary protoliths. mafic enclaves. marble. represented by amphibolite. In the northern part. chert. quartzite. Overlying the Hindoli Group of rocks and Mangalwar Complex with an unconformity occur the next younger groups of rocks classified as the Rajpura-Dariba (subdivided into the Bhinder. Dariba.bearing chlorite-actinolite schist. BIF. chlorite schist. interrupted by Berach Granite. In the southern end of the Hindoli belt.in The Mangalwar Complex is considered presently as representing Archaean primary granite– greenstone belt. Pansal. long linear bodies of felsic volcanics in the form of qurtzo-feldspathic rocks are also present. All these synformal metasedimentary basins/structures of Lower Proterozoic age occur in disjointed belts as outliers and they are mostly composed of dolomite. Pur-Banera (classified into the Pur. chert.blogspot. are the major components of the western Indian Precambrian shield. talc-chlorite schist and talcose serpentinites with asbestos veins. amphibolite. Rewara. Malikhera. banded ferruginous chert and quartizite. zinc and lead mineralization with gold. tin and tungsten at places. calc-gneiss. are by far the most prolific of the suite. In the sourthern part of BGC terrain. Besides. calcareous biotite schist. The Hindoli Group comprises a low-grade (greenschist facies) sequence predominated by turbidite and volcanics. also known as fold belts or shear belts. Tiranga and Samodi Formations). occurs along the eastern and southeastern flank of the BGC/Mangalwar Complex. High-magnesia mafic and ultramafic enclaves include tremolite-actinolite schist. migmatised gabbroic rock and chlorite schist . The Aravalli-Delhi Province is composed of Proterozoic supracrustals sequences classified as the Aravalli Supergroup (Early Proterozoic) and Delhi Supergroup (Early to Middle Proterozoic). fuchsite quartzite. The arcuate belt of the nearly continuous Hindoli Group. garnetiferous mica schist. Sindesar and Satdudhia Formations). The BGC are devoid of mineralization except for the Rampura-Agucha zinc-lead deposits. the Hindoli Group is overlain unconformably by the Vindhyan Supergroup of rocks and further south by the Deccan Trap basalts. ARAVALLI-DELHI MOBILE BELTS The Aravalli and Delhi mobile belts. pelitic schist. migmatitic gneiss-amphibolite association of the greenstone sequence is represented by banded bimodal gneiss. grunerite-garnet schist. Jahazpur and Sawar Groups (subdivided into the Morhi and the Ghatiali Formations) which are exposed in a series of isolated linear belts. magnetite and garnet. These belts are metallogenically important with copper. graphite-kyanite-staurolite schist.visit: grvmalaikalam. Metamorphic and structural parameters backed up by geochronological data have 31 . calc-silicate rock and marble. Pali.. representing deepwater facies. conglomerate. Jaipur.e. The Delwara Group forms the basal part of the Aravalli Supergroup initiating with basal conglomerate followed upwards by basic volcanics and associated pyroclastics.Fold Belt include Jaisamand Granite. Intrusives within the Aravalli .in clearly demonstrated that the BGC was a crystalline basement upon which the rocks of the Proterozoic Aravalli and Delhi Supergroups were deposited. Narukot. i.blogspot. Rajsamand. Salumbar Granite.visit: grvmalaikalam. quartzite. The Delhi Supergroup occurs in the form of two distinct fold belts. The rocks of the Aravalli Supergroup show an inverted V-shaped map pattern with an arcuate disposition with the apex of the V located near Nathdwara. Udaipur and Sirohi distrcits. shallow marine carbonate and carbonaceous sediments with local development of phosphatic and non-phosphatic algal biostromes. The Jharol Group is a thick flysch-like accumulation in a distal trough represented by dominantly phyllite and intercalated quartzite with minor carbonate rocks. Khandia. Jaban. The Aravalli Supergroup shows two distinct ‘facies sequence’ indicating deep-sea and near-shore shelf environments interpreted by many as eugeosynclinal-miogeosynclinal couple or as forelandhinterland duplex. Besides. 32 . evidences of an unconformity between the BGC and the overlying supracrustal suites have been widely proposed. Bharatpur. The ultramafic rocks. The Debari Group is mainly composed of a thick sequence of conglomeratequartzite followed by dolomitic limestone and mica schist sequence. whereas the western part of the Supergroup has a totally carbonate free distal facies. Recent mapping by GSI in the Khetri area have identified and separated the Khetri fold belt (Khetri basin) from the NDFB by a basement-cover sequence separable from the main NDFB of the Alwar-Bayana-Lalsot basin. with thin bands of arenite. Metabasic volcanics occur near the base of Aravalli Supergroup. The Debari and the Jharol Groups exposed in Rajasthan are represented by the Lunavada (subdivided into Kalinjara. Wagidora and Kadana Formation) and the Champaner Groups (subdivided into Lambia. Rajgarh Formation) in Gujarat state. Dausa. The eastern part of the Supergroup is occupied by carbonate. Ahar River Granite. Udaisagar and Dakan Granite. Shivrajpur. the North Delhi Fold Belt (NDFB) in Alwar. The Aravalli Supergroup has been subdivided into a tripartite lower Delwara Group. The width of the belt in the north is about 40 km gradually fanning out to 150 km in the south in Gujarat state. Lakapa Granite and Dudar Gneiss. Sikar and Jhunjhunu districts and the South Delhi Fold Belt (SDFB) in Ajmer. occur in the Aravalli Supergroup in the Rakhabdev-Dungarpur area and in the area between Jharol and Gogunda. represented mainly by serpentinite and its metasomatic alteration products. phyllite and proximal greywacke representing shelf facies. middle Debari Group and the upper Jharol Group. and (2) along a narrow linear belt (Main Delhi Synclinorium of Heron. namely.visit: grvmalaikalam. Phenai Mata Complex.to Neoproterozoic times are represented by the Sendra-Ambaji granite gneiss. Badalgarh. 33 . The Lower Aravalli rocks of Udaisagar-Umra Belts. Mount Girnar Complex. Rajula Suite of rocks. The two sectors differ in terms of lithofacies.. The rock types of the SDFB continue towards south into Gujarat. the middle Alwar Group (mainly areanaceous and sub-divided into Rajgarh. Bayana and Damdama Formations in the Bayana-Lalsot basin) and the upper Ajabgarh Group (mainly argillaceous constituting a lower Kushalgarh Formation and an upper Weir Formation). Osham Hill Complex. The magmatic activity during the Meso. The major stratigraphic units of the Delhi Supergroup in the NDFB are the lower Raialo Group (mainly calcareous). cadmium with minor gold and molybdenum. Kankwarhi and Pratapgarh Formations in the Alwar-Jaipur basin and Jogipura. Alech Hill Complex. occurring east of the Bhim Group. structure. The Rajpura-Dariba-Bethumni belt of polymetallic sulphide mineralization in Aravalli Supergroup is rich in ores of zinc. Another group of rocks. Five lithotectionic units. Several important alkaline and other igneous complexes of Gujarat include the Barda Igneous Complex.blogspot. The major Pb-Zn reserves are hosted in Bhilwara-Aravalli Supergroup rocks in Agucha. Barotiya. copper. viz. all of them together forming the SDFB in Rajasthan and Gujarat. have been delineated from west to east. The Delhi Supergroup forming the Delhi fold belt of Rajasthan and Gujarat occurs in two sectors. (1) in Alwar-Bayana-Khetri region. Rajgarh and Bhim. magmatism and metallogeny. is tentatively included in the eastern basin. Erinpura Granite and Idar Granite. Godhra granite gneiss. lead. Basantgarh. 1953) forming the rib of the Aravalli mountain range in central and southwestern Rajasthan and northern Gujarat. silver. namely. Sendra. and Amba Dongar Complex. Kanessara Igneous Complex. the Devgarh Group. Tectonic discordance in the form of early ductile shear zones and superposed brittle-ductile shear zones demarcate the boundary surfaces of each unit. The Khetri fold belt (Khetri basin) has been identified and separated from the NDFB in the Khetri area by a basement-cover sequence separable from the main NDFB of the Alwar-Bayana-Lalsot basin. Pavagarh Volcanic Complex.in The Delhi Supergroup metasediments and related extrusive igneous rocks rest unconformably or with a structural discordance over the Bhilwara Supergroup in the northeastern and the central parts and over the Aravalli metasediments(?BGC) in the southwestern part of Rajasthan and contiguous parts of Gujarat. Chamardi-Choghat Complex. Kayar-Ghughra. Udaipur district host uranium and copper and phosporite deposits around Udaipur and Sallopat in Banswara district. Minor occurrences are noted in Hinglaz Mata area (Dungarpur district) Ladera area (Jaipur district). Pur-Banera belts of Rajasthan with association of silver with Pb-Zn ores of Zawar. (Five parallel lode bearing) zones extending over a total strike length of 2 km are delineated. Gadwal and Velligallu with a marked nonconformity. Abujhmar. gold is also noted to occur in Pindwara-Watera belt.deposited in a basin temponally and spatially overlapping the Cuddapah Supergroup.visit: grvmalaikalam. Indravati. referred to as Purana (meaning ‘old’) basins by Holland (!907). The sedimentary fill is largely arenaceous and argillaceous with subordinate calcareous and dolomitic components.long concave eastern thrusted contact. It lies above the Peninsular Gneiss and the linear greenstone belts of Kadiri. Kaladgi-Bhima. wheras the sediments to the north form a continuous Vindhyan Basin. which is about 20 km long. 34 . Rajpura-Dariba. 1987). Bharak areas of Udaipur. the southernmost intracratonic basin. Cuddapah Basin The Cuddapah Basin. have contact with the mobile belts. PURANA BASINS Peninsular India witnessed the development of a number of large intracratonic/ pericratonic platformal sedimentary basins. intruded by sills and basaltic flows. and from associated copper ores of the Khetri copper belt.. Rajsamand and Bhilwara districts. The major reserves of gold are from the Jagpura-Bhukia belt in Banswara district of Rajasthan. Chhattisgarh and Vindhyan. namely i) Papaghni Group ii) Chitravati Group iii) Nallamalai Group and one formation.km. Most of these basins except Kaladgi-Bhima. The gencralised stratigraphy is shown in Table 6. Besides. is crescent shaped with its convex side towards west and with a 450. during late Palaeoproterozoic to Neoproterozoic period. This includes Cuddapah. Rajpura-Dariba. namely iv) Srisailam Quartzite while Kurnool is retained as a separate single Group (Nagaraja Rao et al. The Cuddapah Supergroup of rocks is subdivided into three groups.blogspot. The basins to the south of the Son-NarmadaTapti (SONATA) lineament occur as isolated basins. Calcareous precipitates dominate the Kurnool Group.in Zawar. Pakhal. blogspot.in Table 6: Stratigraphy of Cuddapah Supergroup and Kurnool Group ________________________________________________________________________ Major Rock Types Supergroup/Group Nandyal Shale Koilkuntla Limestone Paniam Quartzite Kurnool Group Owk Shale Narji Limestone Banganapalli Quartzite (diamoma bering conglomerate) ---------------------------------------------Unconformity-------------------------------------------Srisailam Quartzite ---------------------------------------------Unconformity-------------------------------------------Cumbum(Pullampet) Formation Nallamalai Group Bairenkonda Nagari Quartzite -------Angular unconformity----Gandikota Quartzite Tadpatri Formation Cuddapah Chitravati Group Supergroup Pulivendla Quartzite --------Disconformity-------------Vempalle Formation Papaghni Group Gulcheru Quartzite ------------------------------------------Unconformity----------------------------------------------Archaean This basin is historically famous for the world renowned diamonds like the Koh-i-noor. the Hope and the Orloff identified in the kimberlite diatremes of EDC at Wajrakarur in Anantapur district of Andhra Pradesh and Narayanpet in Mahbhubnagar district of Andhra Pradesh and lamproite dykes at Chelima-Zangamrajupalle and Krishna lamproite fields. Basemetal mineral deposits are known in the Cumbum Formation. Zangamrajupalle-Varikunta. and Gani-Kalva and Pulivendla belts. Rayavaram-Chinavani-Palle. Vempalle and Tadpatri Formations spread in Agnigundala. the Great Moghul.visit: grvmalaikalam. 35 . The largest barite deposit in the world with a reserve of 74 million tonne is located in Mangampeta in Cuddapah district in the Pullampet Shale of the Cuddapah Supergroup. The southwestern belt extends from Khammam in the southeast to Adilabad in the northwest and extends further into Maharashtra State. chrysotile variety of asbestos mined in the Pulivendla serpentinised belt and phosphorite occurrences in Tadpatri. The sediments of the basin occur as two mutually parallel belts.wide stretch of Gondwana sediments separating them. The Pakhal Basin includes unmetamorphosed (except locally) and unfossiliferous sediments of the Pakhal Supergroup. this basin has huge reserves of cement-grade limestone in the Narji limestone in Kurnool and Palnad subbasins. Cumbum Formations and Srisailam Quartzites of Cuddapah Supergroup. Cement-grade limestone of Bagalkot. represent intracratonic basins occurring above the Archaean Dharwar greenstones with a nonconformity and partly covered by the uppermost cretaceous Tertiary Deccan Traps to its north and west. The northeastern belt extends from a little north of Bhadrachalam in the southeast. Kaladgi and Badami basin The Kaladgi and Badami sediments. Mineral potential in the sediments of this basin includes cement-grade limestone. and phosphorite within shale. use of limestone as dimensional stone.The sediments consist of orthoquartzite-argillite-carbonate association without volcanics and are least metamorphosed and deformed. unconformably overlain by the rocks of Penganga Group and Sullavai Sandstone.in Besides. The Penganga Group of rocks is correlated with the rocks of Kurnool Group. 36 . with about 40.SE direction for 350 km along the Pranhita – Godavari Valley from Andhra Pradesh in the SE to Maharashtra in the NW.blogspot.visit: grvmalaikalam. haematite iron ore occurrences in Kerkalmati and usage of Kerur arenites as dimensional stone are the mineral resources found in these platformal sediments.km.The Pakhal Supergroup correlatable to the Cuddapah Supergroup rest on the Archaean Gneiss Complex.. exposed in northwestern Karnataka extending to South-Western Maharashtra. to a little beyond Chanda (Maharashtra) in the northwest. Bhima Basin This is the smallest and youngest of the Purana basins located in Karnataka and Andhra Pradesh overlying Archaean basement rocks and covered by Deccan Traps and consists of clastic sediments and limestone. Pakhal Basin The Proterozoic Pakhal Basin extends in NW. nodules or layers of barytes. in Conglomerate. Abujhmar Basin The Abujhmar Plateau of Bastar district. Bailadila and Nandgaon Groups. of which the middle Kanger Formation represents a deep intracratonic basinal system with deposition of lime-mud used in cement and flux. siltstone and shale with calcareous sediments. Cherla. located west of Ampani reveals a 280. This basin is bounded on the west by the NNE-SSW. and carry a pile of lavas and intruded by dykes and sills. quartzite of this basin are used for refractory purposes in ferrosilicon industry. 220 km2 in extent.visit: grvmalaikalam. and the BIF of Bailadila Group underlie in the north.This incomplete sequence has been correlated with the basal stage of the Indravati-Chhattisgarh Basin and Upper Kurnool equivalent of Cuddapah Basin (Balakrishnan and Babu. on the south by the WNWESE trending lineament and the Indravati river. 1987). shale.lying sandstone. Ampani Outlier An outlier. Ramagundam and Amarapad areas. The sediments are metamorphosed locally. haematite iron ore from the ferruginous grits and quartzites extending from Bayyaram to Nilavanch.trending Kotri Lineament. Mineral resources includes streaks and disseminations of copper ores (chalcopyrite) in dolomite. subarkosic sandstone. barytes at Sripuram.grade limestone from Putunur. They are correlated with the Cuddapah Basin and Dhanjori Group of south Singhbhum and considered younger to Nandgaon Volcanics. The rocks of this basin are classified into three formations. clay at Marigundem. arkose and limestone the Penganga.thick sequence of polymict conglomerate. shale or quartzite (with old workings) near Venkatapuram. shale. Kimberliteclan rocks were discovered in this basin in Tokapal Kimberlite Field. and Madharam shales and west of Gunjeda. and sandstone the Sullavai. limestone and stromatolitic dolomite above the Archaean basement. 37 . arkose. Chhattisgarh State. cement. Sarkar Ragaboyanagudem and Manikaran villages. Cheruvapuram and Pochavaram.and flux. Indravati Basin The Proterozoic Indravati Basin in the Bastar Craton extends for 9000 km2 revealing flat. dimensional stones in Sullavai sandstone and Jakkaram arkose have been quarried from Chavai. dolomite and quartzite characterize the Pakhals. exposes the sediments in a 3000 km2 rectilinear basin trending NNW-SSE overlying Bengpal.m.blogspot. 38 . Indravati. and Bhander – and twenty-three formations. clay and potash are known and explored to a varying degree. The Vindhyan basin is a major storehouse for limestone. Simla Slate. The Chhattisgarh Basin is correlated with Lower Vindhyan. Ampani and others are considered to have been part of a Greater Chhattisgarh Basin. ochre. Several works have been carried out in this basin in the last 150 years in search of diamonds. The Vindhyan Supergroup has been classified into four groups Semri.blogspot. Attock Slates. Occurrence of copper. diamonds. the Bhaunathpur Basin of Vindhyan Formation is situated south of Son River in Jharkhand. glass sands and building stones. Kurnool and Bhima basins of Peninsular India. Recent exploration for diamond in Pairi-Khariar basin has resulted in the discovery of five kimberlite pipes. They have tuffs and pyroclastics and had a rift history. Rewa. Vindhyan Supergroup The Vindhyan Supergroup is 1 to 4 km thick and extends for about 60. Though the basin to the north of the SONATA and east of GBF is generally depicted as Vindhyan. laterite. lead.000 km2 in the Chhattisgarh State. dolomitic limestone. bauxite. reported occurrence of galena from Narsinghpur. Haimanta Group and the Salt Range beds. two of which are diamondiferous. the Great Boundary Fault (GBF) of Rajasthan in the west and Ganga alluvium to its north. Banjari and Rohtas Fort.in Chhatisgarh Basin The Chhattisgarh Basin covers an area of 33. pyrites from Amjhor. more than forty mineral indicator zones were detected by stream sediment sampling. Kaimur. A small outlier. It has a lower arenaceous and an upper argillaceous-calcareous sedimentary sequence and overlies the Archaean granite gneiss and supracrustals of Chilpi and Sonakhan Groups. The isolated basins of Indravati.visit: grvmalaikalam. limestone and dimensional stones. Vindhyan sedimentation commenced later than the Cuddapah Basin at around 1400 Ma and continued to the end of the Proterozoic to terminate before Cambrian (≈ 570 Ma).000 km2 in a curvilinear basin surrounding the Bundelkhand Granite massif and bounded by the Son-Narmada-Tapti (SONATA) Lineament in the south. It is correlated with the Marwar Supergroup of Trans-Aravalli region of Rajasthan. zinc mineralization and native sulphur are noted at Semri in Bundelkhand. it is represented in Himalaya by the Hazara Slate. In this Mainpur Kimberlite Field. visit: grvmalaikalam. bounded in the south by the Satpura trend and Son-Narmada rift and separated from the Himalayan belt in the north by the Lahore-Delhi shallow ridge. with the Hanseran Evaporite Group and Nagaur Group constituting the Marwar Supergroup. Considering the stratigraphic position of Sakmarian fossil prompt us visualising the remote 39 . The Marwar Supergroup and the Mesozoic basins occurring in Rajasthan are correlated with the Vindhyan Supergroup. The evaporite sequence is 100-160m thick with halite. The shelf of Rajasthan is connected to that of Gujarat with a ridge known as the Jaisalmer Mari Arch with the NW-SE Kanoi Fault truncating the Arch in Thar Desert. Fall in sea level has been attributed to the glacio-eustatic drawdown during the accumulation of ice on uplifted high grounds. The Kathiawar uplift to the south and Radhanpur Barmer Arch to the east form boundaries.Early Cambrian evaporite basin of 50. the Gondwana supercontinent rotated clockwise almost 180o bringing the eastern and northern margin of Gondwanaland from equatorial position to high southern palaeolatitude resulting in widespread glacio-marine and rift-related sedimentation in many of the Gondwana basins during early Permian (Fig. dolomite/dolomitic limestone. potassic salts. GONDWANA BASINS The Gondwana sedimentation which was commenced in Late Carboniferous after the Hercynian orogeny (mid-Carboniferous). There is more than 500m thick Talchir sequence present in many basins. The Upper Proterozoic . The Kutch Basin has Nagar Parkar Massif.5. 1998). which is supposed to have been leaked from the Gondwana sediments underlying the Deccan Trap. Extensive mafic and ultramafic rocks separate this Indus Basin from the Baluchistan Basin. Rann of Kutch depression and Mainland High. Recent borehole data by ONGC from west coast show the presence of recycled Upper Carboniferous palynomorphs.000km2 area. Most part of Talchir sequence is unfossiliferous and the only fossil-bearing horizon within Talchir is at the top part associated with grey shale and limestone band that indicate a Sakmarian age. below 300m of Quaternary sediments in the semi-desert areas of Punjab. Acharyya.in Trans-Aravalli Basins The Proterozoic-Mesozoic basins in the terrain west of the Aravalli-Delhi mobile belt are known as the Trans-Aravalli. During late Carboniferous. anhydrite/gypsum and clay. Haryana and Rajasthan extending beyond to the Salt Range occurrences. occurs in Trans-Aravalli Vindhyans.blogspot. during which almost whole of land surface is represented by nondeposition except the Tethyan margins. North Karanpura. 1932. During Karharbari Formation which is represented by coarse clastic dominated proximal sequence where fluvial processes dominate. Cochostracan & conodonts straddle this boundary.1956. Ib Vally. e. Bisrampur.blogspot. Two distinct groups of marine fossils associated with this transgression were initially reported from Upper part of Talchir Formation in Daltonganj.in possibility of presence of some Upper Carboniferous sediments within the basal part of Talchir Formation in the deeper part of some basins. Palynoevents in Indian Gondwanas correlatable to the multiple marine transgressions caused by deglaciation covered part of Palaeo-Tethyan and Panthalassan margins and extended deep into the plate interior in almost all the continents except Antarctica during Sakmarian. Sahni & Srivastava. Talchir. Umaria. Manendragarh. Based on their recent finding of Eurydesma fauna in western part of Satpura basin Ghosh (2003) proposed a single marine front from east and considered the somewhat different fossil assemblage of Umaria as due to some local bathymetric reasons. Marine Eurydesma and Deltopecten fauna is found in India (both in peninsular and extrapeninsular basins) (Sinor. However. He has excluded the fossils of Badhaura from the Gondwana gamut. Reed. It may indicate the lowering of base level related to regressive phase of the sea.1922. though among the taxa Arthopods do not record any sharp break while ostracodes. Deposition of coal bearing Permian Barakar & Raniganj formations under post glacial warmer condition in a fault-controlled subbasinal structure is quite distinct with enlargement of basinal area. global but determined by specifics of habit. but exclusively in the 40 .g.g. Raniganj. Dickins & Shah.. During the transition of Permo-Triassic boundary paleoenvironment might brought drastic lithological changes in other Gondwana continents .1954. and Badhaura. A coarsening up sequence. Mishra et al. which is more conspicuous in Damodar valley basin belt. presence of conglomerate at the contact of Barakar and Karharbari formation is quite common in many coalfields (e.1961.visit: grvmalaikalam. starting with the shale facies at the top of Talchir Formation and ending at the top of Karharbari Formation is quite distinct. The plants were more dependent on the climatic zonality and related regional lithogenetic variability while invertebrates were more acclimatic. Dutt1965. The extinction of invertebrate at Palaeozoic & Mesozoic boundary is considered globally. Scarcity of plant fossils might indicate that a periglacial environment persisted during the deposition of Karharbari Formation.Ghosh. Where as land plants started to diversify their ecological niches much later than the marine invertebrates. the environment was conducive enough to promote sufficient growth of vegetation resulting in deposition of coal particularly where fluvial system was established.1977). so far reported from different Gondwana Basins are very wide ranging thus helping in no way to ascertain any specific age. the Gondwana lithosequences of different basins within India. Palaeo-climate and the nature of precursor vegetal matter are the prime determinants for formation of different type of heterolithic coal in Indian Gondwana Basins. excepting few instances 41 . Krishnan and Jacob (1956) had made an earliest recorded attempt to build up the International Stratigraphic Laxicon of Gondwana. Subsequently. More over. Plant fossils. On this basis.1971) and which was ratified by the International SubCommittee on Stratigraphic Classification (ISSC) in 1972. it can be stated that" a rotation/ movement of the Indian Gondwana during Permian period was halted at the P-T Boundary and thereby some of the Lithologenetic Belt transgressed in Triassic.Misc.blogspot. giving rise thereby to form huge coal deposits in Gondwana Basins. There after no serious attempt was made to re-classify/ re-build the Gondwana Stratigraphy. in 1971 need of Stratigraphic standardization was actually conceived by adoption of a standard code by the Committee on Stratigraphic Nomenclature of India( Geo. GSI while carrying out 50 K Map compilation work.Surv. it is opined that Palynology is the best suited tool for Gondwana Sequence because of their dominantly Non-marine depositional environment. Palynological data has its own constraints and till date is at best can be considered as corroborative. no-20. Therefore. could be grouped under specific time slots which may serve as powerful tools to arrive at a reasonable correlation framework. The fossil spores & pollens are considered to reflect the past plant life accurately because of Taphonomic factors & hence episodic changes in lineages of presence of a short interval of the temporal scale in the Stratigraphy are well documented by the study of Sporae Dispersae. Bio or chrono stratigraphic divisions and thereby to correlate them.Pub. The different Lithostratigraphic marker horizons of some selective Coalfields have already been prepared by the CW. with the different Palyno-event-marker zones. It is also well known in the Lower Permian. These time planes can be recognized as distinctive Gondwanide events.Ind.visit: grvmalaikalam. the climate was too favourable for triggering the rampant rise of the glossopteris flora . Since the introduction of the term"Gondwana" by Sir Medlicott (1872) no serious attempt was made to define the “Gondwana” into litho. Hence. General geological sequence of the respective coalfields is enclosed in Annexure-I It has been found that marine flooding surfaces within the Permian can be used to define sequence boundaries as well as time slots for dealing with the stratigraphy of the Gondwana Period. Vertebrate fossils are few in India.in Indian continent. favouring the Plant’s life to also transgress. by glaciations during which almost whole of land surface was represented by non-deposition except the Tethyan margins.in and in most cases are not very helpful in assigning pinpoint age.blogspot. related to the movement of the Gondwana continents during Cretaceous. Moreover in most of the cases these intrusives are found to follow the preexisting faults and never displaced by them. any radiometric age data. palaeontological and palaeomagnetic data total span of deposition of the Gondwana Sequence in India was considered to be initiated in Late Carboniferous after the Hercynian orogeny (mid-Carboniferous).visit: grvmalaikalam. in the south where Early Carboniferous/ Devonian rocks are preserved)and at places the sedimentary packages were totally eroded down even to Precambrian level. The end of deposition is considered as the product of major rifting activities as a result of Pangean break-up. Distensional tectonics. for any of the formation in Gondwana basins of India is not available. Fall in sea level has been attributed to the glacio-eustatic drawdown during the accumulation of ice on uplifted high grounds (Veevers and Powell. was accompanied by voluminous eruption of tholeiitic flood basalt and emplacement of sills and dykes. Abundance of coal and carbonaceous materials in the immediately succeeding Permian sediments also suggest an ameliorated humid climate and which was subsequently fluctuated gradually with time along with some what rifting of different basins. Moreover.causing little sedimentation in the low lying peripheral parts in the north and south of Gondwanaland (Ilummedin and other basins of Africa in the North and the foreland basins. where as the Deccan Traps erupted around 65 Ma. which was subsequently affected by the severe erosion . Trachyandesite porphyry is found to occur along the southern main boundary fault of Raigarh Coalfield. Parana-Karoo-Falkland-Elsworth-Bowen. it is more or less accepted that there are two major events of volcanic activity which can be correlated with the Rajmahal Trap and the Deccan Trap. 1987). Mahanadi Valley Basin (Chakraborty. Termination of Gondwana sedimentary deposition in India is considered to be terminated by the deposition of Bagra. sedimentological. Although there were differences in opinion regarding the actual age of these intrusive/effusive.The rock is intrusive within the basement granite and also directly in contact with the Talchir Formation. Chikiala formations during early Cretaceous with the outpouring of Rajmahal Group of volcanics around 110-118 Ma. Igneous activity within the Gondwana basins of peninsular India is represented by dykes/sills of dolerite/basalt and lamprophyre and basic flows as found in many coalfields. 42 . Based on available tectonic. 1999). g Mahanadi Basin) and abrupt/sharp relation by the presence of paleosol zones( e. Rajahmundry Trap occupies about 35 sq km in Rajahmundry area at the north western fringe of Krishna Godavari Basin. South Rewa Basin). but in other part it is gradual.blogspot. there is a significant phase of preKamthi erosion.g.in Almost all the coalfields/basins of the Gondwana contain dykes/sills of dolerite/basalt of varying dimensions except the Talcher and Ib coalfields of Mahanadi Basin and Godavari Valley Basin. Volcanic flows in Meghalaya. Middle -Dicrodium & Upper-Pterophyllum) is more acceptable and seems valid. are considered to be the equivalents of Rajmahal Trap. However. As in widely separated Gondwana basins closely related Unit/Member/Formation so far defined are encountered with gross lithofacies variation along with diversified' fossil record.1996). recently it assumed 43 .g. The Middle Gondwana is also characterized by the record ofTriassic Reptiles. Lamprophyre dykes and sills occurring in Indian Gondwana form a consanguinous suite ranging from ultrabasic mica peridotite to micro-syenite assemblages. Deep drilling by ONGC revealed presence of older trap equivalent to Rajmahal Trap below the Rajahmundry Trap (Biswas. Thus the entire lower Gondwana sedimentation (as mentioned in the Annexur-I ) reflect both gradual/ conformable ( e. e. To sort out these paradoxes. Besides.visit: grvmalaikalam. it is necessary to follow a uniform standard/code in conformity with the International practice while doing interbasinal correlation of different Gondwana basins of Peninsular India. Rajmahal Trap exposed along the western margin of Bengal Basin covering the Gondwana beds of Damodar-Rajmahal Gondwana basins.The upper flow (Rajahmundry Trap) overlies the Maastrichtian –Campanian sediments while the lower flow (Rajmahal equivalent) occurs below the Albian sediments Tripartite Classification of Gondwana exclusively on the basis of floral remains (e. the attempt has been made to define the entire gamout of Gondwana sedimentation by Palyno-Events/ sequences. this Lacuna/Paradox still persists. Amphibians and Estheriids. in the type area of Kamthi. The lithological/ sedimentation breaks. The origin of these intrusives have been linked with Deccan/Rajmahal Trap.g. They are mainly reported from the Damodar Valley Basin close to Rajmahal and the preponderance diminishes towards west beyond Bokaro coalfield. better known as Sylhet Trap.-LowerGlossopteris. as depicted were not synchronous throughout and varied from one basin to basin. Indian Permian coal deposits of Gondwana Sequence are well known for their energy resources and to varying degrees for metallurgical purposes. They have a preference for coal seams and invade them at coal-sandstone interface. Kamthi Barren Measures Motur Barren Measures Barren Measures Barakar Barakar Barakar Barakar Barakar Talchir Talchir Talchir Talchir Talchir DECCAN TRAP (CONTINENTAL BASALT) VOLCANISM Deccan Traps. Raniganj early Late Perm. Pachmarhi Mid. They comprise tholeiitic flood basalts with some picrites. It was envisaged that an integral part of the project would be to locate new virgin potential area. The isotopic ages indicate a 69 to 64 Ma period for the eruption with peak around a narrow span of 1 Ma around 65 Ma. Talchir Panchet Pali Raniganj Lr. Kamthi Bijori Raniganj Lr.in significance repository of coal bed methane. Pachmarhi Gangapur Mid Jurassic Early Jurassic Late Triassic Kota SupraPanchet Dubrajpur Kamthi (undifferenti ated) (Tiki) Up.blogspot. Triassic Bhimaram Mid.visit: grvmalaikalam. Refractory clays are also present within Permian sediments. It extends from Kutch in Gujarat in the west to as far as Belgaum in Karnataka in the south to Rajamundry in Andhra Pradesh in the southeast to Sirguja in Madhya Pradesh in the east to a few remnants in the bauxite laterites in Ranchi-Palamau in Jharkhand. Pachmarhi/ Denwa Yerrapalli early Mid Triassic Early Triassic Panchet late Late Perm. Native copper has been reported from the Deccan basalts near 44 . . The intertrappean fossils are Upper Cretaceous to Lower Eocene in age. STRATIGRAPHIC CORRELATION OF GONDWANA SEQUENCE OF PENINSULAR INDIA INDIA Age DamodarKoel Rajmahal Son Sat pura Mahanadi Godavari Early Cret Chikiala Late Jura-Early Cret Bansa/Chandia Jabalpur Bagra Parsora Up. The Bagh beds in lower Narmada Valley and the Lametas of Jabalpur constitute important infratrappean datums. the second most extensive geological formation in Peninsular India occupies major part (≈75%) of the Maharashtra State. Kamthi Dharmaram Maleri late Mid. Barakar early Early Perm. particularly for coal and also for other commodities like refractor clay and uranium. The traps rest on Upper Cretaceous strata. Barren Measures late Early Perm. Indo-Gangetic (Ganga) Plain occupies the major part of the States of Haryana and Punjab with the upper and part of the middle part of the Ganga Plain in Uttar Pradesh. haematite and maghemite are other associated minerals. Karnataka. The Ganga Plain is a part of the 'Indo .visit: grvmalaikalam. Magnetite. This Plain exposes fluvial sediments of Quaternary period. INDO-GANGETIC – BRAHMAPUTRA PLAIN Indo-Gangetic Plain extends from Aravalli . Belgaum district. particularly for petroleum.Early Pleistocene period. with Deccan Trap volcanism and formation of the Indo-Tsangpo suture welding India with the rest of Asia. submarine topography changed with formation of volcanic chain of islands.Gangetic Foreland Basin'. has revealed that a thick pile of alluvium rests over the Siwalik sequence of Neogene . The contemporary deformation and metamorphism resulted in initiation of major crustal 45 . This alluvium constitutes sedimentary fill of the Ganga Foredeep – the youngest foreland basin. 2006).blogspot.continent collision process during Tertiary period. A sea named variously as the Tethys or Purana evolved to the north of the Indian Shield providing the base for Lesser Himalaya characteristics at 2000 Ma ago. The thickness of the alluvium increases towards north and is maximum adjacent to the Foot Hill Fault (FHF) that marks the northern limit of the Ganga Foredeep Basin. The movement of Indian plate over 7000 km to the north subsequent to the breaking from Africa-Madagascar resulted in notable changes in the geography of Asia.Peninsular Region resulted due to continent . The foredeep sediments extend much to the south of the depositional boundary of the Siwalik Foredeep and rest over the Cratonic rocks of Precambrian period. This foreland basin is developed during upper Tertiary and is closely related to the birth and rise of Himalaya. The Brahmaputra Plains cover the whole of Assam Plains. The withdrawal of this sea marks the beginning and the breakway of Tibetan microcontinent and development of Tethys Himalaya. The evolution of the Himalaya – the largest of the mountain ranges – can be described in a simple way (Balasubrahmanyan.in Handigund (16°25': 75°05').Delhi ridge in the west to the Rajmahal hills in the east. Subsurface exploration. The rest of the middle part of the Ganga Plain falls in Bihar and the terminal part comes in West Bengal where the Bhagirathi river Plains to Indo-Bangladesh border in the east. EXTRA-PENINSULAR REGION The Himalayan mountain chain constituting the Extra. During the tectonically unstable period between Permian and Cretaceous. migmatites and calc-silicates) and intruded by granites some of which are of Tertiary age.to 50. etc.wide zone immediately north of the GangaBrahmaputra alluvium of Miocene to Tertiary age. This is a 10.) and Kumaon Garhwal (U. etc. (ii) The Lesser Himalaya is a 60.This is constituted of Early Tertiary (Subathu-Dagshai-Kasauli-ChunabatiYinkiong) and Late Tertiary (Siwalik) rocks. Nanda Devi.P. Chareota window.P.km. It has Riphean to Palaeozoic platform sediments with some characters of the Peninsular Shield and is overlain by thrust sheets and crystalline nappes.wide zone stretching between the Main Boundary Thrust(MBT) in the south and the Main Central Thrust (MCT) in the north and is made up of autochthonous sedimentaries of Precambrian (Shali-Deoban-Tejam belt) and Palaeozoic-Mesozoic age (Krol-Tal-Subathu) thrust overlain by epizonal metamorphic(Chail-Ramgarh) and mesozonal metamorphic(Jutogh-Munsiari) thrust sheets. Dhaulagiri. Spiti-Zanskar (H. Higher Himalaya and the Trans-Himalaya are the morphotectonic and lithostratigraphic zones from south to north.) in the Higher Himalayan Tethyan basins. The Molasse belt in Siwalik and other foothills with the Main Frontal Thrust (MFT) limit the orogenic margins of the Himalaya against the Ganga Brahmaputra Plains. The Sub-Himalaya.wide zone of Precambrian crystallines exhumed along the greatest uplifted terrain with highest peaks of Himalaya (NunKun.to 80. (iv)The Tethys Himalaya extends to the south of the Trans . Metamorphic crystalline sequences of the Higher Himalaya are overlain unconformably by predominantly marine sediments of Paleozoic and Mesozoic age in parts of Kashmir. There are two belts of Sub-Himalayan Tertiary coalfields trending WNW-ESE in JammuKashmir. At places.km. Everest.to 15. Kulu-Rampur window. made up of katazonal metamorphics (kyanite-sillimanite gneisses. (i) The Sub-Himalaya lies in the extreme south and separated from the northern Lesser Himalaya by Main Boundary Thrust. (iii) The Higher Himalaya is a 10. Sporadic occurrences of bedded barite and polymetallic sulphide mineralisation have been reported from Garbyang and Ralam Formations of Uttar Pradesh. Badrinath. This belt 46 .km. Lesser Himalaya.blogspot. Api.).visit: grvmalaikalam. Kedarnath. Kanchanjunga.Himalayan ranges and comprises predominantly fossiliferous sediments ranging in age from Late Proterozoic to Eocene.in fractures of the Main Central Thrust and Main Boundary Thrust and evolution of the Siwalik basin and leucogranite intrusions of Himalaya. Leopargial. Shali window. the crystalline thrust sheets have been removed by deep erosion in river valleys exposing the autochthonous sedimentaries of ShaliDegboon-Tejam belt as tectonic windows such as Kishtwar window. in bears an unconformable or faulted contact with the Higher Himalaya. in a north to 47 . Karakorum Granitoid Complex (KGC) is a linear batholithic body. This zone is separated from the Tethys Himalaya by Dras Thrust in the south and from the Karakorum Tethys and Granitoid Complex by the Shyok Thrust in the north. Tethyan sequence containing fossiliferous Palaeozoic rocks is well exposed in Garhwal and Kumaon region. the basement to the Tethyan sedimentary sequence. about 20 km wide and 150 km long stretching NW-SE and occupies higher peaks of the Eastern Karakorum and the Pangong mountains. Hispar. The southern belt called the Ladakh Granitoid Complex intrudes the Upper Cretaceous-Eocene rocks of the Indus Suture Zone.visit: grvmalaikalam. consisting of phyllites. one including basal ophiolite followed by basic volcanics and flyschoid sediments and another by ophiolitic melange. Shyok Suture Zone. mica schist. the Lhasa block. The Indus-Tsangpo suture zone (ITSZ) extends as a linear belt all along the IndusTsangpo valleys between the Higher Himalaya to the south and Karakorum – Gangdse ranges to the north. (v) Trans . Along the Karakorum Highway. pegmatite and quartz veins. quartzite. It is characterized by a huge discontinuous. as Lachi.blogspot. tectonically juxtaposed. nearly 2600-km-long batholith comprising rocks ranging from gabbro to granite. about 4500 m thick. i.This granitoid belt extends into the Western Karakorum across Baura range. forming the basement for the fossiliferous Palaeozoic sequence. Karakoram batholith/magmatic arc (KGC) and the Karakoram Supergroup and the Tso Morari Crystalline Complex This zone represents the lithounits brought together during the Eocene collision of North Indian plate elements with the trailing edge of Eurasian plate. The northern belt called the Karakorum Granitoid Complex. Kinnaur basin. This Group is also intruded by granite.Himalaya. The Trans-Himalayan lithotectonic units north of the Indus Suture Zone includes the Ladakh batholith/magmatic arc (Ladakh Granitoid Complex). Biafo to the west of Baltaro. Earlier workers considered it to be of Precambrian age. Two belts of granitoid complexes lie in the Trans-Himalayan region of Ladakh. Lahul and Spiti in Himachal Himalaya. lies to the north of the Indus Suture Zone and intrudes the Late Palaeozoic metamorphites. The Martoli Group. The ITSZ branches into two thrusts―Main Mantle and Main Karakorum―with rocks in between comprising the rocks of the Kohistan Zone. lies to the north of the Indus Suture Zone in Ladakh region and extends eastward into Tibet. This narrow linear belt comprises two units. with lenticles of marble in the upper part overlies the Central Crystallines with a tectonic contact. It is best exposed for about 500 km in the Ladakh region and is referred as the Indus suture zone. So Lamo Formation in Sikkim Himalaya.e. Tenga and Miri Formations and Upper Siwaliks.visit: grvmalaikalam. 48 . The Trans-Himalayan belt comprises two distinct lithopackages viz. Gondwana. In the lower Himalayan region NNE-SSW to NS trends are superimposed on the above regional trends. Rocks of khondalite affinity of Southern Granulite Belt are noticed in the form of graphite-bearing quartz-biotite-sillimanite schists in the Simi Member of Khetabari Formation of Precambrian age in Upper Subansiri district. Subansisri and Siang Himalaya and (ii) Lohit Himalayan).in south section. Arunachal Himalaya The correlation of Arunachal geology with the other parts of Himalaya is a complex job fraught with uncertaintes. the Chilas Layered Complex and the Jijal Complex. In the Lohit Himalayas the rocks exposed belong to Bomdila Group. Tilung Formation and Namdhapa Crystalline Complex are also included in this group. Upper Dibang and Lohit valley areas is juxtaposed against the rocks of the Himalayan belt along the Tidding Suture. the Kohistan-Ladakh batholith. From west to east the Bomdila Group is overlain by the Dirang Formation till east of Subansiri River. migmatites and gneisses overlie the Dirang schists in the higher Himalaya of Kameng district of Arunachal.The lesser Himalayan zones of Arunachal Pradesh are classified into two parts: (i) The Kameng. the K2 consists of Yasin flyschoid sediments. the latter occurring as restites. the Tertiaries.blogspot. In Siyom and Siang River sections. Sela Group of Higher Himalaya comprising high-grade schists. In KamengSubansisri-Siag Himalaya. Hence the geology has been dicussed separately following broad Himalayan classification. Similar sequence of rocks is known as Ithun Formation and Rikor Group in Dibang valley and Lohit valley areas. The granitic and gneissic rocks of Bomdila Group are garnet bearing and highly deformed and mylonitised under ductile domains. The total assemblage of the suture package resembles an ophiolitic melange. A diorite-granodiorite Complex considered to be of Late Paleozoic age is also exposed in Lohit Himalayas . and metavolcanics and ii) the Lohit Granitoid Complex and the Etalin Formation.The NNW-SSE Trans-Himalayan Belt of Arunachal Pradesh exposed in the Upper Siang. Bomdila Group comprise a sequence of low-to medium-grade metasediments with associated gneisses and younger granitoids occupying expansive areas throughout the lesser Himalaya of Arunachal Pradesh from Siang valley in the east to Kameng valley and Bhutan in the west. The ultramafic bodies intruding the para-metamorphites of Ithun Formation in Myodia area have minor amounts of Platinum Group of elements. Bichom Group and the metamorphic rocks are regionally disposed in ENE-WSW to NE-SW trend. Chitra volcanics. i) the suture package comprising Yang Sang Chu Formation and Tidding Formation with serpentinites. in The Upper Tertiary (Mio-Pliocene) molassic sediments constituting the Siwalik Group occurs as a linear belt along the foothills of Arunachal Pradesh extending from Bhutan to just east of Pasighat where it is overlapped by the alluvium. The Tertiary sequence of Arunachal Pradesh is classified into Dafla. In Tamil Nadu. shales. which is considered as the continuation of the Mishimi Thrust. clay and sandstone of Paleocene age.blogspot. it re-appears on the left bank of Dibang River where it is tectonically overlain by the rocks of the Bomdila Group along the Roing Fault. However. The rocks overlying the Miri Quartzite are cherts. Subansiri and Kimin Formations broadly corresponding to the Lower. CENOZOIC FORMATIONS OF THE SHIELD In the southern peninsular India. 49 . Igo valley. the Tertiary sequence is well developed. Thick lignite beds at Neyveli in Cuddalore District were originally thought to belong to Cuddalore Formation. Middle and Upper sub-divisions of the Siwalik Group of northwestern Himalaya and are considered as the northward extension of the Tertiary sequence of Assam. clay and grit. Along the west coast of Kanyakumari district. Cuddalore Formation contains large quantities of fossil wood around Tiruvakkarai in Villupuram District which have been declared and maintained as a National Fossil Wood Park by GSI. Massive and vesicular basaltic and andesitic rocks of Abor volcanics of Phanerozoic age are associated with Miri Quartzites. calcareous shale/mud. The Siwalik Group is bounded to the north by the Main Boundary Fault along which the Pre-Tertiary sequence has been brought over and its southern limit with the alluvium of the Brahmaputra River. These are correlated to Warkhali beds of Mio-Pliocene age of south Kerala and are similar to Cuddalore Formation. the Ariyalur Group of Upper Cretaceous is overlain conformably by a sequence of limestone. the Mio-Pliocene group is represented by fine-grained limestone and gritty sandstone intercalated with pebble beds. Basar-Along areas and in Siang valley areas in Arunachal Pradesh. Beds of shelly limestone. This sequence is named as Niniyur Formation in the Tiruchirapalli sub-basin with its equivalent in Pondicherry sub-basin as Karasur Formation. black shales and carbonates. Rocks of Mio-Pliocene age (early Neogene) termed as Cuddalore Formation occupy a large area along the coast overlapping the Mesozoic sediments and at places over the crystalline basement. These are referred to as Panamparai Sandstone. found to overlie the Archaean unconformably and below the Recent formations.visit: grvmalaikalam. In the coastal tract of Tuticorin and Tirunelveli districts. developed in the western flank of Subansiri valley. a sequence of sandstone and clay with thin lignite seams is recorded. During early Eocene period. about 20 m thick and unconformably overlying the weathered gneisses and charnockites are capped by laterites. In the East Coast. Co. Tertiary coal occurrences are recorded in Jaintia Group.blogspot. Parts of the ophiolite belt have been explored for chromite and other metals like Ni. These Miocene beds. Cu. interrupted by the prograding deltas of major rivers. 50 . They are represented by thick blankets of alluvium. etc. Dupi tila (Mio-Pliocene) and Dihing (Pliocene) Groups also represent both shelf and geosynclinal facies. an index fossil of the Palaeocene age was recognized in the subcrop samples from boreholes of ONGC . QUATERNARY FORMATIONS The Quaternary sediments in the peninsular India occur along the coastal tracts and inland river valleys by narrow continuous palaeo-beach ridges. upheaval confined along a narrow NE-SW-trending track resulted in intrusion of ultramafic cumulates and volcanic members resulting in the formation of the Ophiolite suite of rocks comprising tectonised peridotite.in intercalated with lignite layers are recognised in the southern coastal tracts of South Kanara district. The Tertiary sedimentary history of Assam is an integral part of the tectono-sedimentary setting of the Tertiary sediments of the north-east India and is influenced by the prominent ‘Brahmaputra Arch’ running parallel to Brahmaputra River. beach sand. Jaguli. Mid-Eocene sediment is represented by polymictic conglomerate. these quasi-indurated sequences of sediments are considered to be the extension of Warkhali Beds occupying further south of Kerala. Jalangi and parts of Medinipur. Bardhaman and Birbhum Districts of West Bengal. Tipam (Upper Miocene). The shelf-facies sediments (Jaintia Group) of Eocene age are calcareous and abundantly fossiliferous. The Tertiary rocks of northeast India rest over the weathered platforms of Precambrian rocks. Chromite is the main economic mineral of the ophiolite suite of rocks with Cr2O3 >45% and low TiO2. Bankura. the Tertiary rocks are represented by algal limestone in subcrops at Debagram. Distichoplax biserialis. Surma (Lower Miocene).visit: grvmalaikalam. gravel and colluvial deposits. cumulate ultramafics including dunite. and these comprise of both shelf and geosynclinal-facies sediments of Eocene age represented by the Jaintia and Disang Groups respectively. peridotites and pyroxenites that are exposed in the eastern fringe of North-Eastern Region for about 200 km from Moreh in Manipur in south to north-east of Chiphur in Nagaland in north. In Meghalaya. tuffaceous greywacke and lithic feldspathic arenite. The overlying Barail (Oligocene). Recently. fluvial and lacustrine origin.visit: grvmalaikalam. Mizoram and Nagaland. An active zone of subduction along the Andaman-Java trench lies on the west of the Andaman-Nicobar Islands and continues southward into Indonesia. rutile. Underthusting of the Indian oceanic plate below the Eurasian plate since Cretaceous to present day along this subduction resulted in the formation of a wide accretionary prism and upbuilding of a high forarc-outerarc ridge known as Andaman-Nicobar ridge. Rocks of the Andaman Islands are technically thrusted into a narrow north-southtrending and linear belt paralleling the north-south trend of the Andaman-Java subduction. constituting the southern most part of the Indian subcontinent covering an area of 8249 km2. marshy. Older 51 . The Quaternary sediments were laid down in four major depositional environments. Minor recent sediments also occur in Manipur. The Quaternary sand deposits along the coastal tracts of Kerala and Tamil Nadu are economically exploitable for ilmenite. They occur mostly in a large tract in western Rajasthan known as the Thar Desert. saline tract extending for about 300 km in east-west direction in Kachchha region of Gujarat. The Quaternaries in Rajasthan and Gujarat are assorted deposits of aeolian. running from Myanmar to Indonesia to Indo-Sumatra subduction zone.marine. namely fluvial. Andaman & Nicobar Islands The Andaman-Nicobar Islands represent part of an arcuate island-arc chain. A major part of the area flanking the Brahmaputra River in Lower and Upper Assam is covered by thick Quaternary fluvial sequence. The Andaman & Nicobar (A & N) Islands represent the subaerial part of the submarine fore-arc ridge of the Indonesian Island-arc system.—a vast. The ophiolite occurrences in Andaman Islands are interpreted as thrust slices of oceanic crust scraped off the subducting slab at the toe of the accretionary complex. marine and aeolian. Recent deposits in northeast India are represented by sand-silt-clay sequence in Brahmaputra and Surma River valleys in Assam and in the foot hills of Garo and Khasi hills of Meghalaya. One of the important Quaternary episode in Gujarat is the formation of the Rann Surface. The outerarc-forearc terrain constituting the Andaman-Nicobar Islands is characterized by a complex mosaic of different geological provinces each having its own record of origin and geological evolution vis-a-vis mineral potentiality. zircon and monazite.blogspot. Quaternary sequence located in Imphal valley of Manipur are of both laccustrine and fluvial types. fluvio. soils of various types and laterite.in kankar. flanked on the west by the Bay of Bengal and on the east by the Andaman Sea. 220-440 km off the west coast of India. diopsite. the only active volcano in the Indian subcontinent has recently exploded during May 1991 after lying dormant for a long time. Olivine basalt represents the first phase of eruption. Mineral occurrences include Coralline Limestone. Geologically. The Ophiolites.blogspot. while the second phase witnessed the eruption of high-alumina olivine basalt. 1992).Subsequently it erupted again during 2005. The Narcondam is considered to be a dormant type while the Barren has the history of recurring volcanic eruption since pre-historic age (Halder et al. with a total of about 36 islands and islets. three reefs and five submerged banks. This ancient volcanic cone was at times blown out and a thick pile of pyroclastics got deposited over the surface of the relict cauldron. with three distinct volcanic episodes recorded so far. An initial submarine volcanism. Ophiolitc rocks in Andaman occur as north-south trending dismembered units of subhorizontal sheets thrusted over the much younger Andaman Flysch. possibly taking place in late to postPleistocene time formed a giant volcanic cone representing the ancestral / primordial Barren Island.visit: grvmalaikalam. Lakshadweep Islands The Union Territory of Lakshadweep forms a NE-SW-trending archipelago in the Laccadive-Chagos ridge system in the Arabian Sea. The Barren Island volcano is characterized by resurgent volcanism. Rutland Island in the southern tip of South Andaman Island hosts the largest exposure of the ophiolites. It is located between 8º and 12º30" North latitude and 71º and 74 º East longitudes and consists of twelve atolls. The recent basaltic andesite eruption contains phenocrysts of plagioclase.in continental metamorphic rocks occur as small enclaves within the ophiolite-melange packages.Calcareous sand with high CaO content 52 . The Barren Island volcano. They are Cretaceous-Palaeocene in age and are intermittently exposed from the saddle reef of North Andaman to almost the southern tip of the Great Nicobar Island. 1982). roughly covering 32 sq km.. located about 100 km north and northeast of Port Blair on Andaman Sea. Narcondam and Barren are the two small volcanic islands of Quaternary age. their cover sediments and the Andaman Flysh together are folded into an open anticline (Ray. augite and titanomagnetite set in a hyalopilitic groundmass. Recent Volcanism in Andaman & Nicobar Islands In Andaman & Nicobar Islands. 2006 and in 2009. all the islands are made up of coralline limestone and calcareous coralline sand and its variants. Sets of mesoscopic folds occur in all the sedimentary units associated with ophiolites. Jamshedpur and copper smelter at Ghatsila. including those from overseas for carrying out mineral exploration. The investigations carried out since 1960s provide us first hand information of different mineral occurrences as well as their potential. Innumerable old workings. East India Company started exploration for coal in the eighteenth century with setting up of Geological Survey of India. the GSI oriented its programmes through multidisciplinary surveys and from time to time equipped with state-of-the-art laboratories to back up its various exploration programmes. A few other central and state government organisations were also involved in mineral exploration now and then. the premier Earth science organisation and the second oldest survey of the country. has attracted the world’s attention during the historical time.visit: grvmalaikalam. Copper. mostly in collaboration with foreign organisations. Singhbhum and Aravalli cratons. The liberalization of our National Mineral Policy in 1993 paved the way for entry of private entrepreneurs. iron.in and Guano deposits (P2O5. and gold were also used locally since the day of Indus valley civilizations. Industrial policy formulated after Independence. magnetite and chromite. brought about a radical change in the mining and metallurgical industry. Keeping in tune with the modern trends of mineral exploration. sillimanite. MINERAL RESOURCES OF INDIA INTRODUCTION India has a rich tradition of mineral exploration. Bastar. India was a notable producer of gold in the early part of twentieth century and major exporter of mica. kyanite.72%) in Pilli island 30 km NW of Kavaratti. The crustal elements have to undergo enrichment upto several 53 .blogspot. The database developed by GSI has been found very useful for taking investment decisions by the Multi National Companies. slag heaps are the tell tale signs of this glorious tradition. An ore or mineral deposit represents a geochemically anomalous concentration of elements in a very limited sector of the crust. (0. in 1851 for the systematic geological survey and prospecting for coal. The efforts have led to discovery of several mineral deposits in virgin areas in different parts of the country. GSI has embarked upon the exploration for minerals particularly in favourable geological milieu spread over the Dharwar. Metallurgical industry started with the setting up of steel plants at Burnpur. Second World War created great demand for various minerals and metals including those of strategic importance viz tungsten. The flourishing diamond industry in the Deccan peninsula mainly in the Golconda kingdom.8-11. During the post Independence period.12 million tonnes estimated by IBM in 1970). The concentration of Clarke varies from element to element depending on the economic utilization. meteoric bombardment and formation of primeval crust (Piranjo 1992). The genesis of economic deposits is therefore essentially a question of enrichment. and eventually together near continental size cratonic areas.visit: grvmalaikalam. Massive crustal growth. Iron. Archaean-Proterozoic Transition and Proterozoic proper. 54 . The Archaean Proterozoic boundary was a major turning point in crustal evolution and represents a diachronous and transitional period ranging from 3 Ga to 2. Crustal evolution during Archaean: The Archaean forms the formative stages of the earth’s history. Subduction.5 Ga. Later perhaps in response to partial melting of this lithosphere and the products of erosion of the early consolidated magmas. In the Indian context major metallogenic episodes have taken place during Archaean.67 and 2. As a result lithosphere was presumably thin and somewhat buoyant. manganese and chromium etc were formed in distinct episodes mostly from Archaean to Mesoproterozoic. The aggregation of these micropltaes could have given rise to Protocontinents.blogspot. major out gassing.The aggregation of a super continental mass resulted in the accumulation of heat in the mantle beneath. core segregation. These cratons were composed of granitic rocks and greenstone belts. The presence of an unconformity is typical separating highly deformed Archaean rocks from the little deformed Proterozoic cratonic sequences.5 to 4 times its present value. lithospheric thickening. The crustal processes associated with crustal growth and recycling leading to metal concentration and formation of deposits is refeered by the term’metallogeny’. ore felsic rocks were formed and accreted leading to the formation of first sialic microplates.5 Ga is estimated to have been 2. Archaean heat flow between 3. was probably little developed and mantle convection gave rise to a series of small jostling lithospheric plates.8 and 2. A major intrusive event characterised by large-scale granitic magmatism is identified between 2. if any. The Proterozoic Eon was the most significant one when intraplate tectonics played a major role in earth’s evolution of magmatism. Thus large deposits of base metal and basemetal-noble metals. Initially these were made-up of mafic and ultramafic rocks.5 Ga . decrease in heat flow and a possible change in mantle convection pattern occurred. metamorphism and ore genesis.in orders to attain the status of an economic deposit. Ti and Vanadium bearing Magnetite. exogenous and metamorphogenic series.in Genesis and localisation of economic deposits:The grouping of commercial types of ore deposits is based on a single genetic classification ie endogenous. Endogenic cycle and endogenic deposits: Magmatic deposits: Magmatic cycle (both extrusive and intrusives) is responsible for concentration of many important metallic deposits. native copper. The exogenic include weathering. A genetic connection between both is often difficult to establish because exhalation carrying ore minerals get intermixed with the hydrosphere and atmosphere and are deposited as chemogenic sediments. placer. Some of them are early magmatic and late magmatic with reference to the intrusion. To this class belong the sedimentary exhalative deposits closely related to time and space with volcanic episodes (e. The endogenic series incorporates magmatic. copper.visit: grvmalaikalam. cobalt. metasomatic greisen type etc. Hydrothermal origin is attributed to many of the metalliferous deposits of copper. lead etc and fluorite. Uranium. deposits of stratiform Zinc. The following table summarizes some empirical data on the igneous rock-ore linkage. barite deposits.g. massive sulfides and stratiform type groups. silver. Nickel. Rock Type Associated Ore Kimberlite and Lamproite Diamond Dunite-Peridotite. skarn. beryl. gold Nephelene syenite Corundum Granite and granite pegmatite Tin-Tungsten. Platinum Group Norite-Gabbro. nickel Dolerite. Pyroxenite Chromite. The podiform chromite mineralsiation associated with ultramafic rocks are examples of deposits of early magmatic concentration. quartz monzonite Porphyry copper. The mineral rich solutions migrated from magma source gets precipatetd at different levels in the crust along strcturally favourable traps depending on the ambient pressure temperature conditions of precipitation at different crustal levels. tourmaline 55 . pegmatitic.blogspot. sedimentary. Ores may be genetically related to specific intrusives as magmatic concentration and magmatic emanation exuded from magma during its consolidation. volcanogenic hydrothermal. plutonogenic hydrothermal.Anorthosite PGE. radium. BIF. mineralised waters and brines. monzonite Magnetite. Volcanic Hosted Massive type Sulphide type Pb-Zn-Cu deposits).-gold-Mo-Ag- Syenite Magnetite. carbonatite. diorite. gold. gold Granodiorite. India was leading in diamond mining. deposits locked at depth.etc. gold. This type of deposits is abundant in the Precambrian shield of Indian Peninsula. Tin placers of Bastar District. It represents insitu products of interaction of the stable crustal blocks with the dynamic atmosphere. diamond. ilmenite. that is.in Exogenic cycle and exogenic deposits: The mineral deposits formed at deeper zones of the crust under high temperature and pressure conditions are unstable in the interface of atmosphere. As per the National Mineral Policy.Till the discovery of the Brazilian diamond fields. mineral occurrences of India is presented in detail for geologically potential areas in consonance with the national policy goals. Mechanical concentration of resistant minerals results in the formation of placer deposits of monazite.Only significant mineralization with possible economic significance have been described.2008. All these lead to geochemical fractionation of elements. Nizam (440ct). low pressure and abundant water. Orloff(300 ct) and Daryainoor(185 ct).visit: grvmalaikalam. Large deposits of coal are found associated with Gondwana sediments. Nickel. and aluminium takes place in the weathering cycle under warm tropical conditions in the form of laterite and bauxite cappings. Another important example of exogenous deposits is coal. which emphasized for non-fuel and non-coal minerals. These are formed by large scale deposition of vegetation materials entrapped in the alluvial sediments brought in by the rivers which during the course of geologic time due to consolidation and lithification transformed into coal beds. the Hope (67ct). Pitt/Regent (410 ct). DIAMOND India has the distinction of prducing many of the historically famous diamonds like the Kohinoor (186 ct). This is important source of energy in the country. 56 .Konkan Coast. Examples of this type of deposits are the beach placers of Ilmenitemagnetite bearing sand placers of Kerala . platinum etc. which incidentally leads to formation of a number of mineral deposits. Enrichment of iron. The dynamic agencies of hydrologic cycle act upon crustal blocks and bring about concentration of heavy minerals. hydrosphere and biosphere which are characterised by low temperature.blogspot. cassiterite. the Great Moghul (787 ct). diamond placers in Madhya Pradesh and Wairagarh. garnet. The known areas of occurrences of diamond source rocks are broadly grouped into three diamond provinces.Three N-S zones. Considering the Cratons and presence of diamonds and the source rocks. Wajrakarur Kimberlite Field (WKF). (11) Mahanadi Gondwana Graben and (12) Godavari Gondwana Graben. (9) Structural Corridor of Son – Narmada rift zone. (7) Southern part of Singhbhum Craton including Singhbhum Mobile Belt. (2) West Dharwar Province. The SIDP is confined to the Dharwar Craton in the states of Andhra Pradesh. areas have been prognosticated for kimberlite search in India. Karnataka and Maharashtra. Narayanpet Kimberlite Field (NKF). Chhattishgarh. Jharkhand and Madhya Pradesh. The kimberlites localised within the Eastern block of the Dharwar Craton are grouped into four kimberlite fields. the Central Indian Diamond Province (CIDP) and the East Indian Diamond Province (EIDP). (4) West Bastar Craton.e.000 km2 and includes both primary (Kimberlites/Lamproites) and secondary source rocks (conglomerates and gravels) for diamond. viz. (ii) the middle zone of lamproites (~1350 Ma) covering Nallamalai Fold Belt (NFB) and PGC along the northeastern and northern margin of CB. Orissa. (3) East Bastar Craton including parts of Eastern Ghat Mobile Belt (EGMB). The major lamproite dykes occurring along the eastern margin of the Craton i. (6) North of Central Indian Suture (CIS). within the Nallamalai Fold Belt (NFB) and close to the north eastern margin of the Cuddapah basin are included in the Chelima. Rajasthan and Uttar Pradesh and the EIDP to the Bastar and Singhbhum Cratons in the states of Maharashtra. Each of these Provinces extends approximately over an area of 100. (5) Southern part of Bundelkhand – Aravalli Craton . and (iii) the western zone of kimberlites (~1100 Ma) covering PGC to the west of CB. viz. the CIDP to the Aravalli Craton in the states of Madhya Pradesh. The SIDP consists of both primary and secondary source rocks of diamond. namely the South Indian Diamond Province (SIDP). (10) Structural Corridor of Tapti Lineament Zone.Tungabhadra Kimberlite Field(TKF) and Raichur Kimberlite Field(RKF). (8) Raigarh Mobile Belt.They are: (1) South Indian Diamond Province (SIDP) including East Dharwar Craton and adjoining Dharwar Mobile Belt.Zangamrajupalle Lamproite Field (CLF) and Jaggayyapeta-Krishna Lamproite Field (JLF) respectively.in Diamond occurrences in India are quite widespread. (i) the eastern zone of alkaline syenites / alkali granites (1600–1400 Ma) extending from the eastern tectonic contact of EGMB with DC to the eastern margin of CB. 57 . are recognised.blogspot.visit: grvmalaikalam. has incidence of diamond – 0 to 35 cpht – with average at 2 to 3 cpht.Twenty-one kimberlites of WKF are distributed in three clusters viz. Though this diamond occurrence is rather localised. Investigation for diamond bearing conglomerates has been revived recently from Banganapalle.in Until now. Alluvial diamonds are known to occur in southern India along Krishna. 3. in that. only the WKF is found to contain diamondiferous pipes. conglomerates. Narayanpet (NK 1-10) and Bhima clusters (BK 1-5 and RK-1).The conglomerate range in thickness from 1 to 50 cm with an average of 10 cm. Maddur (MK 1-11). Chigicherla cluster (CC 1-5) and Kalyandurg cluster (KL 1-3). The conglomerate occurs as disconnected outcrops in a curved belt 250 km long in the western part of the Cuddapah Basin and about 120 km long in the Palnad Basin. igneous intrusives and the basement. explored by various agencies. it assumes significance. The basal conglomerate in the Banganapalle Quartzite Formation in the Kurnool Group is the main diamond-bearing stratigraphic unit so far known in the Cuddapah basin (Table 6). many of the world famous diamonds were reportedly recovered from gravels of the area. The Banganapalle conglomerate. Tammarajupalle and Ramallakota-Viryapalle-Yerubayi. There are 34 kimberlite bodies in NKF distributed in Kotakunda (KK1-7). Tungabadra and Penner Rivers.The diamond-bearing conglomerates are subarkose and classified as chert pebble-.visit: grvmalaikalam. Wajrakarur-Lattavaram cluster (Pipe 1-13). and 7.The diamond incidences (in carat per hundred tones-cpht) of Pipe 1 to 13 are 0.9 with the high value of 45 in the overburden of Pipe 7. The lamproites are distributed in 12 clusters.blogspot. The source of the conglomerates is traced to the west comprising lower Cuddapah sequences. Mineralogical composition of WKF indicates their derivation from shallower depths above the diamond window in the inhomogenous mantle.5. 0. para-. Old workings in Krishna Valleys occur in T2/T3 terraces at Panchalingala. Secondary sourced diamonds in South India can be traced to the Proterozoic Cumbum conglomerate (Cuddapah Supergroup). 75% of the diamonds recovered are gem variety and the largest one weighed 6 ct.. Vajragiri-Munimadugu. Another localized occurrence of old mining activity confining to the Mesozoic /Tertiary (?) sandstone is around Mallavelli to the east of Vijaywada and south-eastern side of the Eastern Ghat Mobile Belt. with clasts of chert and jasper and subordinate vein quartz embedded in sand-silt matrix. oligomictic-. Kurnool district near the confluence of Tungabhadra with Krishna River to Paritala down stream in Krishna 58 .78 to 1. Banganapalle conglomerate (Kurnool Group) and UpperTertiary Gollapalli/Malavalli conglomerate from the extensive old workings.3. The main source of diamonds in the country is from Majhgawan with about 10 carats per 100 tonnes within the pipes. The CIDP confined to the Aravalli Craton in the states of Madhya Pradesh. over a distance of > 400 kms. respectively. Kimberlitic rocks discovered in this province are only a few and sporadic and are reported from the Bundelkhand granite terrain.3 million carats. Rajasthan and Uttar Pradesh also consists of primary and secondary source rocks. Kundair. with an average annual production of 16. The estimated reserve of diamond in this pipe is of the order of 1. The kimberlites/ lamproites (~1100Ma) intruding into the Kaimur Group of rocks are found along the western margin of the Vindhyan basin adjoining the Bundelkhand granite and are included in Majhgawan Kimberlite/Lamproite Field.The gravels mainly of Krishna river along with those of the Pennar river.The Pleistocene-Holocene gravels of Krishna and PennerRivers have been worked for diamond from different terraces (T2/T3 and T3) with probable primary source from WKF and other unknown sources.000 carats.6 carat per 100 tonnes.blogspot.visit: grvmalaikalam.7 and 0. Jhiri shale. The extension of Hatupur conglomerate block has been explored by MECL. The occurrence of diamonds over such a long belt viewed in the light of only two known diamond bearing pipes at one end of the belt strongly point to contribution of diamonds from more pipes.in district . The National Mineral Development Corporation Ltd is exploiting Majhgawan kimberlite/lamproite. the only diamond producing mine. Diamond occurrences in the Godavari gravels are sporadic. The conglomerates at Shahidan mine at the base of the Jhiri shale have been worked for a long time and have a higher potential of 26 carats per 100 tonnes. The Hinota and Jungel have low incidence of 0. and Gahadra sandstone Formations of the Rewa Group of rocks of late Proterozoic age. The Vindhyan Supergroup of rocks host a major share of diamonds produced from the Panna Diamond Belt in the form of three diamondiferous conglomerate horizons associated with the Itwa sandstone. Sagileru. The NE-SW trending Panna Diamond belt with established ancient mining activity is located within this province. NMDC also took up mining of a large gravel block at Ramkheria but abandoned the work due to operational difficulties. Hundri and Ramileru yielded large quantities of diamonds. which have been producing about 15000 carats per year of which a third are of the gem quality. Diamondiferous alluvial gravels are found mostly along the banks of the Ken-Ranj-Baghain rivers and lateritic gravels over the Baghain and Gahadra Sandstone Formations. The lamproite pipe at Hinota has low diamond incidence and is not worked.The incidence of 59 .This is the only belt where active mining for diamond is presently carried out in the country. A little amount of diamond is being recovered from placer occurrences. Orissa. Chhattishgarh. As a result of GSI's work several prospective blocks have been identified for further investigation. both in the state of Chhattisgarh. The ancient workings in Wairagarh area appear to be in the conglomerates as well as gravels. Mahantola Salaia and Urdana. and Mand rivers in Chhattishgarh and Tel-Mahanadi rivers in Orissa. DGM and private enterpreneurs. The recent discovery of kimberlitic / lamproitic rocks in Nuapada district of Orissa has opened a new area of primary source rocks for diamond.. and Hirakud area in Orissa and KoelSankh river areas inJharkhand. A. Ib. Kimberlite discoveries in the province are very recent and investigations carried out in different parts of the Bastar Craton led to identification of two new kimberlite fields (1) Mainpur kimberlite Field (MKF) and (2) Tokapal Kimberlite Field (TKF).visit: grvmalaikalam. Prognostication for mineral search is essential at different stages of prospecting from regional operations over large areas to detailed operations over narrowed down target areas. Orissa. Such blocks are listed below and short description on their status is enclosed. Some of the kimberlites in the MKF are known to be diamondiferous. Diamond is also reported from the river gravels and alluvial caps at Chanda. The EIDP confined to the Bastar and Singhbhum Cratons in the states of Maharashtra. A few of the Cretaceous lamproites intruding into the Gondwana sediments of the Damodar valley Coalfields and South Rewa Gondwana basin show similarities to that of lamproitic rocks. Bahradih and Kodomali of Raipur district by GSI.in diamonds in Panna diamond belt from gravels of Baghain River (near Ramkheria village) and other streams are good at 23 carats per 100 tonnes. The kimberlites of the MKF intruded into the Khariar group of rocks and those of TKF into the Indravati group of rocks of late Proterozoic age. Meaningful prospecting and exploration for diamond and kimberlites depend much on the right type of prognostication. LAMPROITE/ KIMBERLITES A.Diamond-bearing pipes in the former field have been identified from Payalikhand. Jharkhand and Madhya Pradesh is known for ancient diamond mining activity at a few places only viz. Diamonds are also reported in the gravels of Maini.blogspot. The conglomerates and grit are associated with either the middle Proterozoic Sakoli group or the early Proterozoic Dongargarh Group of rocks. A few lamproite dykes have been discovered recently in adjoining Bargarh district. Wairagarh area in Maharashtra.1 MAJHGAWAN KIMBERLITE/LAMPROITE DIATREME 60 . (2) deciphering the geometry of the body and study of different petrographic varieties at depth and (3) establishing incidence of diamond in the 'extended arm' of kimberlite on the basis of surface sampling with the help of deep pits. the district Headquarters. In the western and southern periphery. 63O/2 Extent: 515 x 330 m diatreme. The yellow and blue grounds are well developed with a capping of 5 to 6m of soil. it is connected to Panna by an all weather road. Treatment of about 1643.(24039': 80002'). however. The contact with the host rock dips at fairly constant angle of 7000inwards. 5 boreholes were drilled from outside the pipe area. During shallow drilling.70 metres of drilling in 25 boreholes was done to study the pipe. A total of 2943.20 ct indicating an incidence of 0. the kimberlite is highly sheared and traversed by a network of calcite veins.2 HINOTA KIMBERLITE DIATREME 61 . Exploration: The exploration programme was aimed at: (1) establishing offshoots of the kimberlite diatreme. The contact between the kimberlite diatreme and the Baghain sandstone is normally sharp. To study the behaviour of the Majhgawan kimberlite at depth. Panna district. it reduces to about 125m at a depth of 330m. A. two prominent offshoots were delineated upto a depth of 40 m and an additional reserve of kimberlite (0. The drilling has established the extension of pipe to a vertical depth of 330 m. At present. The diatreme contains both cognate and accidental xenoliths.14 Mt) has been established upto a depth of 40 m.43 cpht as against 10 cpht in the main pipe. The pipe continues to further depth.visit: grvmalaikalam. Topography: The pipe intrudes into the Baghain sandstone. Since Majhgawan pipe is a diamond producing mine. Geological setup: The Majhgawan kimberlite diatreme identified as lamproite is a downward tapering.in Geographic data: Location: Majhgawan. which forms a flat geomorphic surface with a height of 360m to 400m above MSL. As against the diameter of the pipe. The wall of the pipe indicates an inward dip of about 700 to 800. which is about 330 m on surface. The contact between the yellow and the blue ground is at an average depth of 14 m from the surface. Toposheet no.blogspot. the mine is approximately 80m deep with a number of benches.71t of kimberlite from offshoot yielded 14 diamonds weighing 7. cone shaped body measuring about 515 x 330 m in plan. Access: Majhgawan pipe is located about 20 km south-west of Panna. Panna district. CONGLOMERATES B. (24040': 80001'). 63 D/5 Extent: Hatupur block is 3 km x 3 km in extent. Toposheet no. Panna district. It is well recognised on satellite imageries also. 62 .A total of 228. Caution: The Hinota pipe falls in the Panna National Park area and to obtain prospecting lease. 63D/2 Extent: 200 x 180 m diatreme. The pipe forms a topographic depression. Access: The block is located about 23 km ENE of Panna on Panna-Paharikhera Road. followed by about 25 m of earthy yellow and greenish clayey matter and then blue ground upto a depth of 60 to 75m ending up in hard kimberlite. Hatupur. Geological setup: The Hinota diatreme is emplaced into the Baghain Sandstone Formation of the Kaimur Group (Vindhyan Supergoup). the pipe is recognised by its high density of vegetation and negative topography. which shows a very low incidence of diamond Recommendations: As diamond incidence is low. The drilling in the Hinota pipe indicated top 2. and to carry out large scale operations or even preliminary surveys. The pipe was discovered as a result of magnetic and electrical resistivity surveys by GSI. Exploration: Atotal of 631.in Geographic data Location: NNW of Hinota Village.50m deep shaft was sunk in the pipe. B. On the aerial photographs.65 m of drilling was done in 3 boreholes. which indicated that the body extends beyond 160m in depth.Shaft Sinking: One 18.40 tonnes of material from the shaft was treated and only two diamonds weighing 1. Government of India.blogspot.1 HATUPUR BLOCK Geographic data: Location: Hatupur. On surface. Toposheet no.5m of detrital material. a prior permission from the Ministry of Environment. the diameter of the pipe is 200 x 180 m with a slight NW-SE elongation.71 ct were recovered.visit: grvmalaikalam. Access: Hinota kimberlite diatreme is located about 20 km WSW of Panna. Rakhel and Damulua villages are located within the block. is necessary. further investigation in this pipe is unwarranted.(240048': 80025') . Topography: The pipe is emplaced into the Baghain sandstone which forms a flat geomorphic surface with a height of 360m to 400m. visit: grvmalaikalam.blogspot.in Topography: The block fringes at Gahadara sandstone scarps in the southeastern part of the block, with an elevation difference of about 70m .There is a small hill in the eastern part of the block with a height of 440m. Geological setup: The Jhiri shales are exposed on the surface in the entire block. At the base of the Jhiri shale, a diamondiferous conglomerate horizon (Jhiri conglomerate), varying in thickness from 4 cm to 54 cm, exists. The Jhiri shale is underlain by Itwa Sandstone Formation. Towards the top of the Itwa Sandstone Formation, another diamondiferous conglomerate horizon (known as Itwa conglomerate) exists. The Jhiri and Itwa conglomerates are separated by 2 to 3 m thick sandstone horizon. The Itwa Sandstone Formation and Jhiri Shale Formation (with conglomerate) show very gentle dip towards SSE. The gradient is 1.5 to 2 m per 100 m. Exploration : The area has been mapped on 1:12,500 scale to demarcate conglomerate horizons, diamondiferous lateritic and alluvial gravels and detailed mapping of about 5 sq.km on 1:2000 scale. Drilling:In the western block the grid was laid at 200m intersection and in the eastern block at 250 m intersection. A total of 3345.95 m of drilling was done in 108 boreholes. The drill hole data revealed that the thickness of the Jhiri conglomerate ranges from about 1 cm to 70 cm. The depth of conglomerate varies from 4.55m to 36.35m.The Itwa conglomerate is separated from the Jhiri conglomerate by a non-diamondiferrous shale /sandstone horizon, the thickness of which varies from 2 to 4 m. The thicker conglomerate horizons also carry sandstone interbeds. The thickness of Itwa conglomerate varies from 1 cm to 2.42m and depth from surface varies from 3.42 m to 62.28m. Core loss has also been recorded in a few drill holes. In view of this, much thicker horizon of conglomerate is expected in the pits than in boreholes. Isopach map for the Jhiri and the Itwa conglomerates indicates irregular distribution of conglomerate. Both the conglomerates are thicker along palaeochannels than adjoining parts. The palaeochannels are oriented along NE-SW and E-W directions. Isolated patches of thick conglomerate are also recorded. The stratum contour plan of the base of the Itwa conglomerate horizon shows uniform and conspicuous south-easterly gradient. 36 shafts (2.5 x 2.5m), ranging in depth from 5m to 34.75m, were sunk on a grid varying from 100 to 250m to excavate the conglomerates. At the bottom of the shaft, where the Itwa conglomerate was encountered, two east-west oriented drives (1.8m height, 2.1m width and 6m length on each side) were driven to win the requisite quantity of conglomerate. The average thickness of conglomerate in shafts worked out to be 60 cm, varying from 17cm to 1.40m. A total of 4746.92 t of conglomerate was obtained from 6494.50 cu m. of excavation, which was treated at NMDC plant, Majhgawan. Dimensions of explored prospects: i) Sub-block A: The sub-block (area 0.3 sq.km) was proved to contain conglomerate reserves of 63 visit: grvmalaikalam.blogspot.in about 0.45 Mt with a diamond incidence of 27.91 cpht. This block is open at both ends, indicating the possibility of its further extension towards east and towards south-west. MECL has drilled in the eastern extensions of the block, the results of which are yet to be received. ii) Sub-block B: These sub-block measures 750 x 500m. Proved reserves of pure and diluted conglomerate estimated are 0.53 Mt and 1.49 Mt, respectively. Treatment results of the samples drawn are not available so far. The depth of the Itwa conglomerate varies from 20.95m to 29.10m iii) Sub-block C: The block is along a NW-SE trending channel. Thickness of the Itwa conglomerate ranges from 1.14 to 1.80m and depth varies from 6.45 to 21.65m. On the basis of the data of three pits (P-28, P-35 and P-36) and drives, about 0.31 Mt of undiluted and 0.74 Mt of diluted conglomerate of proved category have been estimated. Probable reserves of 0.60 Mt of undiluted conglomerate and 2.72 Mt diluted conglomerate have been estimated on the basis of drill hole data. The treatment results are not yet available. iv) Sub-block D: It is a small block located in the northeastern corner of the Hatupur block. The thickness of the Itwa conglomerate varies between 22 and 30 cm and depth varies from 8 to 8.5 m. Probable reserves of the conglomerate have been estimated at 0.106 Mt. for the undiluted and 0.742 Mt for the diluted categories. v) Sub block E: It is 1 km long, trending N-S and defined by drill holes. The thickness of Itwa conglomerate varies from 10 to 77cm and depth from 12.70 to 25.15m. No pits have been sunk in this sub block. On the basis of the drill hole data, probable reserves of the conglomerates have been estimated at 0.378 Mt of undiluted and 1.49 Mt of diluted conglomerate. vi) Sub-block F: It has a dimension of 500 x 500m and is a south-easterly extension of the subblock C. The depth of the Itwa conglomerate varies from 23.40 to 26.05m and thickness from 29 cm to 1.70m. On the basis of the drill hole and pit data, proved and probable reserves ofdiluted conglomerate have been estimated at 0.247 Mt and 0.495 Mt respectively. Diamonds: The percentage of gem quality of diamonds is very high (55%). Off-colour and industrial diamonds constitute 19% and 26% of the total diamonds. The largest sizes of diamonds recovered so far, during the exploratory operations, are 3.38 ct (industrial variety), 2.27 ct (gem quality) and 1.68 ct (off colour). Average size of gem, off-colour and industrial varieties is 0.6 ct, 0.45 ct and 0.63 ct, respectively. B.2 SHAHIDAN BLOCK Geographic data: Location: 2.5 Km NE of Panna, Panna district. Coordinates: 24044': 80012'; Toposheet no. 63 D/2;Extent : 2700 X 700 m Topography: Gently rolling terrain. Geological setup: Jhiri conglomerate occurs at the base and as interbeds within the JhiriShale and siltstone of the upper part of the Rewa Group. It forms escarpment to the SW and NE of Panna. The 64 visit: grvmalaikalam.blogspot.in conglomerate is coarse, pebbly or granular, with subrounded granules of jasper, chert, sandstone and shale. It is rather well sorted with a sandy matrix. Exploration: Shahidan area has the record of best and larger size diamond recovery. Data computed from the operations of one of the large and systematically managed mines in Shahidan area indicated diamond incidence of 43 cpht. During 1972-74, GSI drilled 20 boreholes which indicated that the cumulative thickness of conglomerate to the SSE of Janakpur is above 30 cm. During 1980-85, mapping (on 1:5000 scale) and drilling (62 boreholes by MECL) was done. Drilling showed an average thickness of 20 cm of conglomerate. 10 pits sunk at drill hole sites indicated, on an average, 1.7 times greater thickness of conglomerate.The northern part of the area has a number of old workings which are upto 15m deep and waterlogged, causing seepage problem. A part of the northern section is in reserve forest, while the southern part is under cultivation. B.3 GANJA - SHAHPUR BLOCK Geographic data: Location: Near Ganja - Shahpur village, Panna district. Toposheet: 63 D/5 Topography: Gently rolling terrain. Geological Set up Both Itwa and Jhiri conglomerates are encountered in the area. The Jhiri conglomerate is both matrix as also clast supported. The matrix supported conglomerate has 15% to 40% of clasts set in an argillaceous groundmass. The clasts are generally of granule size. These include white quartzite, vein quartz, grey quartzite, green shale, cream quartzite, jasper, pink quartzite and chert. Exploration: 16 holes drilled in the area encountered Jhiri conglomerate at a depth of 12.15m in the northwest and at 49.30m in the southeast, down the dip. This is in conformity with the regional dip of the formation.The Itwa conglomerate is intersected at a depth of 13.48m in the northwest and 50.50m in the southeast. Thickness of Itwa conglomerate varies from 6 to 70 cm.Drill hole data also indicated that there is a rapid variation in the number of bands of Jhiri conglomerate from 1 to 6. The Itwa conglomerate has generally one or two bands, except for southwestern side where 5 bands are recorded. . Reserve: On the basis of drill-hole data, indicated reserves of the Jhiri conglomerate is about 6.74 Mt and that of the Itwa conglomerate is about 4.44 Mt C. RIVER GRAVELS Geographic data: Location: Itwa, Brijpur, Ramkheria villages, Panna district. 65 visit: grvmalaikalam.blogspot.in Coordinates: 24047'- 24049': 80023'- 80030'; Toposheet no. 63 D/5 Extent: Gravel zone extends from Ramkheria (24049': 80027') in the east to Itwa (24047’: 800 23') in the west. Access: The area lies about 20 Km ENE of Panna and an all weather road between Panna and Paharikeria runs through the entire length of gravel zone. Topography: The area is practically flat, with the Baghain River incising into the flood plain deposits. Exploration : Systematic mapping (1:50,000) of alluvial zone was done as part of regional mapping.The area around and along the Baghain river was mapped on 1 : 12,500 scale as a part of delineation of diamondiferous gravel zones.Geophysical survey of the gravel along the entire river section in ItwaRamkheria section was done and the depth of bed rock was demarcated by taking cross traverses. Dimension of the prospect: The area covers a length of approximately 15 km and width of 1 to 2 km.Diamondiferous gravel is restricted to the basal part of the alluvial pile and its thickness varies from 30 cm to 4 m. It comprises boulders and pebbles of sandstone, shale and laterite, set in sandy matrix. Diamond Incidence: Bulk sampling by the GSI in 1956 in diamondiferous alluvial gravel of Ramkheria indicated an incidence of 26 cpht. The exploration by NMDC proved a resource of about 1,15,000 ct with incidence of about 16 cpht. Recommendations : Ramkheria gravel deposits indicate higher diamond incidence with higher percentage of gem quality diamonds than the Majhgawan kimberlite. This prospect appears to be quite promising provided prior exploration is done in the gravel. A few areas were delineated on the basis of photogeological studies for detailed exploration along the Baghain River. D. BUNDELKHAND BASEMENT Several ultrabasic bodies are found in the Bundelkhand granite massif,emplaced after or along with the granitic rocks. Preliminary exploration revealed diamonds, small in size. However, in view of their possible regional relevance in the emplacement of diamond bearing pipe rocks, short descriptions are given below. D.1 ANGOR AND BANDHA ULTRABASIC BODIES Geographic Data: Location : 0.5 km north of Angor Village (24044':79025'; Toposheet no.54 P/6), on the SagarChhatarpur state Highway and 130 km SW of Panna,Chhattarpur district 66 Recommendations In view of the diamond incidence. Groundmass contains calcite and dusty opaques like ilmenite. trending in NNW-SSE direction and another 170m long and 30m wide body located 0. black in colour and porphyritic with phenocrysts of altered olivine. both the bodies could be subjected to further investigation. about 10m wide and covered by soil at both ends.05 ct). Extent: 10m long and 50cm to 1m wide. Panna district. trends N 30 E . D. Exploration : : Geophysical surveys indicated a 450 m long and 200m wide body.2 DONGRAHA ULTRABASIC ROCK Geographic data: Location : East of Dongraha (24051': 80008').Six large pits reaching to a depth of 10m were put and two diamonds totalling 0. which continues beyond 289m depth. Toposheet: 63 D/1 Extent: The outcrop measures 1 m long and 50 cm wide. Panna district. 86 tonnes of material treated yielded two diamonds weighing 1. underlain by harzburgite. underlain by brecciated carbonated pyroxenite.52 carats.40 tonnes of excavated material. It is a dyke-like body.3 ULTRABASIC ROCKS OF HARSA Geographic data: Location: 1.5 km NW of the first body. Exploration: No exploration was carried out.A similar body occurs near Bandha (240 39′:790 19'. In course of another excavation. Drilling indicates top 7 -12m weathered zones. D.80 tonnes of treated material yielded five diamonds weighing 3. . NMDC treated 1000 tonnes without any recovery of diamond. 54 P/6) to the southwest of Gulganj.visit: grvmalaikalam.2 carats were recorded after treating 937. Geological setup: The rock is intensely weathered.blogspot. 311.62 ct (one gem 0. 67 .S 30 W. magnetite and possibly perovskite.in .35m were drilled in the main body.7 boreholes totalling 792.5 km north of Harsa village (24046':80006').57ct and one industrial 1.Prospect : Angor Ultramafic prospect Topography The granitic country is flat Geological setup The ultramafic rocks are found in Bundelkhand granites exposed mainly on the eastern side of the road but much of it has been levelled off to form cultivated land. The rock has been identified as lamprophyre.7 km WNW of Biharpur. the other side is covered by residual soil. located between the Bastar Craton on south-west and the Singhbhum Craton on north-east. aggregating 298. D 4 ULTRABASIC DYKE NEAR BARIARPUR BARRAGE Geographic data: Location: East bank of Ken River. as proved by drilling three holes. 63 D/9 Extent: 600m long and 1 to 5m wide. is well exposed more than 1 km long in the west bank canal of the barrage. No kimberlite was intersected in any of the holes and it appears that this dyke pinches off at very shallow depth. Mand and Sankh and their tributaries. is manifested by the presence of diamond in all the streams of Ib. further extension possible. Exploration: Two boreholes. Panna district. In Bastar 68 . Exploration: No exploration for recovery of diamond was carried out. Coordinates: 24057’: 80031' .visit: grvmalaikalam. ends covered under soil. the body should be further investigated. The Archon of Bastar Craton is bordered by Protons of Raigarh Mobile Belt and Eastern Ghat Mobile Belt and this tectonic scenario is important in regional prognostication for diamond and kimberlite in Bastar Craton. It continues under soil cover for 600m. carbonate and quartz veins.43m.5 BASALTIC KIMBERLITE OF BIHARPUR AREA Geographic data: Location: 0. varying in thickness from 5 to 10m and. Recommendation: In view of large strike extension and diamond incidence.in Geological set up: The outcrop shows sharp contact with prophyritic pink granite. Two pits were sunk in the eastern bank of the Ken River and treatment of 138 tonnes of material from one of the pits yielded one diamond (off-colour) weighing 0. were drilled. and 55 tonnes of material treated but no diamonds were recovered. PROSPECTS IN CHHATTISGARH The Chhattisgarh State forms a part of Bastar Craton extending on west to Maharashtra and on east to Orissa. spaced 200m apart.44 ct. green to greenish brown. Panna district Coordinates: 24051': 80006'. Toposheet no. 5m to 10m wide trending N 50 E -S 50W. The body cuts through Bundelkhand granite and shows contact metasomatism. rich in carbonate kankars. Geological set up: A dyke-like body. The rock is traversed by serpentine. It is of great significance that the Raigarh Mobile Belt.The rock is grey. D. north of Barrage.Toposheet no. Maini.blogspot.:63 D/1. About 33 cu m excavation was done. reddish mica and opaques. showing olivine. Kimberlitic rocks: their occurrence and distribution Five kimberlitic diatremes have been located in a linear span of 12. g) the Raigarh Proterozoic crystallines bordering the Bastar Craton. the Proterozoic platformal belts over the cratonic area have been selected as first priority blocks for investigation of kimberlite. A.Considering all the positive features. Payalikhand-II (50m x 50m). Pairi-Khariar basin. the other two being Panna in northern Madhya Pradesh and Wajrakarur (including Chigicherla and Kalyandurg kimberlites) in Andhra Pradesh.in Craton there has been no major thermal activity after 2000 Ma. Sabri basin and Albaka basin. which are likely to be associated with kimberlitic bodies. Exploration activities by the GSI and the State Government have led to the identification of five kimberlite pipes (including three diamondiferous pipes) and more than 40 kimberlitic indicator anomaly zones in the MKF.blogspot. MKF is located in the south-eastern part of the Raipur district of the state of Chhattisgarh in Central India.Most of the diatremes are circular in plan while Bahradih diatreme is elliptical. the following target areas have been prognosticated in search for kimberlites. f) the southern part of Chhattisgarh basin and adjoining granitic terrain.visit: grvmalaikalam. two Kimberlite fields have been identified which are Mainpur Kimberlite Field in Raipur district and Tokapal Kimberlite Field in Bastar district. Ampani basin. The area of each block has been tentatively kept at 5000 Sq. Amongst 69 . e) the Albaka and Abujhmar basins. The prominent Proterozoic basins are Chhattisgarh basin. d) Saraipalli area comprising rocks of Chhattisgarh basin and the adjoining granitic terrain. a) The Pairi-Khariar basin and surrounding granitic terrain. Kodomali (300m across) and Bahradih (300m x 200m). The area is marked by presence of platform cover sediments which protects the kimberlite diatremes from erosion. Indravati basin. The kimberlitic diatremes are Payalikhand-I (92010'10": 82021'00") (100m x 100m). Km. MAINPUR KIMBERLITE FIELD (RAIPUR DISTRICT) The Mainpur Kimberlite Field (MKF) is one of the three established diamond bearing kimberlite fields in Peninsular India. so far. Hence. A total of 14 priority target blocks have been demarcated of which 11 are in Chhattisgarh and three in Madhya Pradesh.5 km in the Mainpur Kimberlite Field.The eastern and central parts of the craton are priority areas because they represent the low heat flow and high permeability zones. b) the Indravati basin and adjoining gneissic complex on west and south. 135km SE of Raipur city. In the Chhattisgarh State. c) the Sabari basin and adjoining gneissic complex. Jangra( (>50m across). intrusive Bundeli granitoid and the sedimentary cover sequences of Pairi and Ampani Groups and Chhattisgarh Super Group. BAHRADIH DIATREME Geographical data Location: Bahradih (20012'30":82012' 00".blogspot. spinel. 169 km from Raipur Topography: 460m above MSL Geological set up: The Payalikhand area comprises a complex lithological assemblage represented by metavolcanics and metasedimentary sequences of Sonakhan Group. Exploration: Two diatremes have been located along the slope of a foothill of the Khariar plateau. 2. rocks of Baya Gneiss Complex. Raipur district. ToposheetNo: 64L/4). PAYALIKHAND DIATREMES Geographical data: Location: Payalikhand (20010'10: 82021'00". highly altered kimberlitic rock as green earth. Raipur district. Diamond contents/Heavy minerals: Diamondiferous` A. khondalite and charnockite suite of rocks of the Eastern Ghat Mobile Belt. MKF Field Dimension Trend: 50m x50m Emplacement control: Circular within granitoid rocks 64L/8 Outcrop characteristics: Along break in slope. Toposheet No: 64 L/8). 1. 12 Km northwest of Payalikhand Topography: Approx 300m above M. highly altered kimberlitic rock (green earth) diatreme facies Diamond contents/Heavy minerals: Diamondiferous and garnet. MKF Field Dimension Trend: 100m x100m Emplacement control: Circular within granitoid rocks (64L/8) Outcrop characteristics: Expressed as a break in slope.visit: grvmalaikalam. Characteristics of the diatremes: Number and name of kimberlite body: Payalikhand-I. A.in the diatremes only Kodomali exhibits fresh rock exposures while others have been weathered to green earth at the surface. clinopyroxene Number and name of kimberlite body: Payalikhand-II.S.L 70 . diatreme facies Diamond contents/Heavy minerals: Diamondiferous and garnet. orthopyroxene. Characteristics of the diatreme Name of kimberlite body: Jangra (200 08′30″: 820 19’ 40”). highly altered kimberlitic rock (green earth). Dimension Trend: 50m x 50m Emplacement control: Circular within granitoid rocks 64L/8 Outcrop characteristics: Ampitheatrical depression within granitoid Diamond contents/heavy minerals: Not known/garnet and spinel A. spinel. clinopyroxene. KODOMALI DIATREME Kodomali (20011' 10": 820 14' 08") kimberlite exposes as a dyke with WNW-ESE trend and is the only diatreme with rock exposure visible at the surface. The near surface alteration as green earth is not much as compared to other diatremes. JANGRA DIATREME Jangra diatreme surfaces at an altitude of 500m from MSL. Since the kimberlite pipe does not crop out above the Khariar cover sediments. Exploration: The Bahradih diatreme is located in an ampitheatre like depression surrounded by resistant granitoid rocks.blogspot. 3. Characteristics of the diatreme Dimension Trend: 300m x 300m Diamond contents/Heavy minerals: Diamondiferous and garnet. 4. The kimberlite pipe located at Baharadih is elliptical in shape. it is therefore.in Geological Set up: The geological set up is same as that of Payalikhand Block. Emplacement control: Sub circular within granitoid rocks (64L/4) Outcrop characteristics: Ampitheatrical depression. ilmenite and olivine 71 . clinopyroxene. presumed that it has only intruded part of the sequence. spinel. Like other diatremes. Characteristics of the diatreme: Name of kimberlite body: Bahradih Dimension Trend: 300m x 200m. amongst the five known diatremes in Mainpur Kimberlite Field. Bahradih diatreme surfaces at an altitude of 560m from MSL. this diatreme is also surrounded by the granitoids.Presence of xenoliths of consolidated shale and sandstone within the weathered kimberlite indicate post Khariar age of diatremes.visit: grvmalaikalam. phlogopite A. The borehole core samples indicate multiple intrusions at different levels with deposition of tuffs in the upper part. The body 72 . 2.The Indravati basinal area forms the east – central part of Bastar Craton. there are kimberlitic flows in phases overlain and underlain by Indravati sediments.The Tokapal. Payalikhand I and II and Jangra diatremes have been classified as diatreme facies rocks. TOKAPAL KCR (KIMBERLITE CLAN ROCK) BODY The Tokapal rock is exposed in pit section and the rock is greenish in colour and shows typical kimberlitic clast-matrix texture and flowage structure within sediments (Jagdalpur Formation) in the form of flows (65E/16). B. without much erosion. B. Bhejripadar and Parpa-Parakot areas and the Tokapal Kimberlite Field. Crater facies material has been preserved as xenoliths within Payalikhand-I and -II diatremes.blogspot. It is also interesting to note that in Bastar.The rock shows crude banding and top portion is lateritised and covered by black soil horizon. TOKAPAL KIMBERLITE FIELD (BASTAR DISTRICT) The regional search for kimberlites in Indravati basin has located kimberlite clan rocks in Tokapal. Bahradih. diatreme and hypabyssal. Only Kodomali rocks are classified as hypabassal facies Recommendation: The MKF has scope for further work to establish more kimberlite pipes and evaluation of their diamond potentiality. The NW-SE trending dyke swarms as well as major lineaments and faults possibly indicate reactivated mantle permeable zones along which the kimberlitic pipes have been emplaced within the Proterozoic cover sediments. The Bastar kimberlites are in the crater facies.visit: grvmalaikalam. The kimberlitic pipes have intruded along NW-SE trending fracturers exhibited by mafic dyke swarms. Diamond :content : Not known B. DUGANPAL KCR BODY The Duganpal kimberlitic rock exposed in the Duganpal nala section has been exposed by drilling. viz.1.in Kimberlites of Mainpur kimberlite field have been classified into three volcanic facies. Duganpal. BHEJRIPADAR KCR BODY The Bhejripadar kimberlitic body is located near village Bhejripadar (65 E/16). Diamond content: Not known B. 3. Duganpal and Parpa-Parakot kimberlitic rocks probably indicate multiple intrusions from a single or multiple feeders covering an area with 5km length and 1 km width. crater. The area is occupied by the Archaean-Proterozoic rocks of Bastar Craton. Diamond content: Not known B.EXPLORATION FOR KCR IN RAIGARH MOBILE BELT The exploration for KCR was also conducted in the Tapti Lineament Zone (TLZ) in parts of Raigarh and Surguja districts of Raigarh Mobile Belt from 1994 to 2000 on the basis of reported diamond incidences in the river gravels of Ib. PALEOPLACER DIAMONDS OF WAIRAGARH. From 36. falling in Chandrapur and Garchiroli districts of Maharastra has revealed chrome diopside and G5 garnet. PROSPECTS IN MAHARASTRA Indicator mineral survey carried out in the western part of Bastar craton. Stream sediment sampling in the area revealed presence of kimberlitic pyrope garnet which are found to be G-9 type of lherzolitic derivative. South Africa.The chrome pyroxenes show some similarity with the pyroxenes from the Monastry kimberlite field. Detailed sampling in this area is recommended. In addition G-5 garnet has also been discovered from stream sediment samples. MAHARASHTRA: Diamond incidence is known from conglomerates of Wairagarh area in Maharashtra. Diamond content: Not known C. in terms of their Ca/ (Ca + Mg) and Mg/(Mg + Fe) ratio with chromium. NNW-SSE trending low 73 .67m to 62. The Wairagarh area exposes a narrow stretch of (10km x 6km). Utial and Talda drainages. PARPA – PARAKOT KCR BODY The kimberlitic rock in Parpa – Parakot sector was observed from the borewell cores drilled by the State Agricultural Department.blogspot. but no primary source of diamond has been located except one grain of chromite falling in the edge of kimberlite field. A major part of the area forms a part of Bardwar sub basin of Chhattisgarh supergroup. D. Maini. The borehole data show the presence of kimberlitic tuffs and pyroclastic rocks below 19.69m greenish black massive kimberlite was observed.87m from the surface upto 36. 4. Mand.visit: grvmalaikalam.in is exposed within the sandstone unit of Tirathgarh Formation. SARANGARH SECTOR The Sarangarh area falls in the north eastern part of Chhattisgarh basin. .A total of 6000 sq km area was covered by PGRS studies and stream sediment sampling.67 m. The crater facies rocks are concealed under the soil and laterite cover of >20m. visit: grvmalaikalam.blogspot.in grade, highly deformed meta sedimentary belt within Archaean Amgaon Gneiss and forms a part of the western part of Bastar Craton. An octahedral diamond (3.5mm long and 2.5mm wide, 0.15 carat) was recently recovered during the GSI investigations of the conglomerate unit of WMS. Along with diamond other heavy assemblages identified include ilmenite, garnet (G-5 garnet, almandine, grossular and andraditic garnets), pyroxenes, amphibole, staurolite, chrome spinel and rare tourmaline. This find has opened up new vistas of diamond search in similar geological milieu in the western Bastar Craton. PROSPECTS IN ORISSA With Multisensor Twin otter aero-geophysical survey carried out by the Airborne Mineral Survey and Exploration Wing (AMSE Wing) of Geological Survey of India during 1994-98 along E-W flight lines at intervals of 500m with a mean terrain clearance of 80m covering an area of about 27,850 sq. km. from Mainpur Payalikhand area in the south to Raigarh-Sundergarh area in the north around Chhattishgarh- Orissa border in search of kimberlite,. NE-SW trending olivine lamproite dyke cross cutting a NW-SE trending dolerite dyke has been discovered near Sakri village, Bargarh district, Orissa. Discovery of this lamproite has raised hopes of finding more such dykes and main lamproite bodies along the ideal setting of the contact of Bastar Craton and Eastern Ghat Mobile Belt. It may be mentioned here that this present setting is similar to the Krishna lamproite field (KLF) on the eastern margin of Dharwar Craton just outside the NE horn of Cuddapah Basin in Andhra Pradesh. Discovery of a lamproite dyke on the margin of Bastar Craton and Eastern Ghat Mobile Belt and incidence of several kimberlite indicators in Mainpur-Gariaband and Khariar roadPaikamal area prove that the integrated strategy is well founded and worth continuing further to utilize the vast amount of aero-geophysical data available with GSI pertaining to this area. Recently State DGM has recovered diamond from a pipe in Kalmidadar. The Cratonic domain of western Orissa lying in tectonic juxtaposition with circum cratonic EGMB is a promising regional target of primary diamond exploration due to old diamond panning records and recent discovery of kimberlite diatremes in adjoining state of Chattisgarh having identical geological milieu. KIMBERLITES AND LAMPROITES OF SOUTH INDIA 74 visit: grvmalaikalam.blogspot.in Kimberlites and lamproites are located in about 270 x 180 Km area in Wajrakarur-LattavaramChigicherla-Kalyandurg area (WKF) in Anantapur district, Andhra Pradesh (A.P.), Narayanpet Kimberlite Field (NKF) in Mahboobnagar district, A.P.and Gulbarga district of Karnataka and Chelima-Zangamrajupalle area (CZLF) in Prakasam district,A.P. and Jaggayyapeta Lamproite Field(JLF) also known as Krishna Lamproite Field of Krishna and Nalgonda districts of A.P. These kimberlites and lamproites are known to occur only from the Eastern Dharwar Cratonic block. The WKF (14005'/ – 15003: 77018' – 77023'; Toposheet nos 57E/8 & F/5) measures 120kmx60km with kimberlites emplaced into the gneisses and schist belt.A total of 21 kimberlites are distributed in 3 clusters, viz, (i) Wajrakarur – Lattavaram cluster – 13 bodies (pipe – 1 to pipe-13) (ii) Chigicherla cluster – 5 bodies (CC-1 to CC-5) (iii)Kalyandurg cluster – 3 bodies (Kl-1 to Kl-3) Majority of the pipes in WKF are diamondiferous. During 2004, two new kimberlite bodies have been reported from Timmasamudram(TK1 & TK-2). The (NKF) is located about 150 km southwest of Hyderabad and 200 km north of the WKF. It measures 60 x 40 km in extent. The Kimberlites of (NKF), occur in four noticeable clusters, viz., (i) Maddur cluster – 11 bodies (MK-1 to MK-11) (ii) Kotakonda cluster – 7 bodies (KK-1 to KK-7) (iii)Narayanpet cluster – 10 bodies (NK-1 to NK-10) (iv)Bhima cluster – 6 bodies (BK-1 to BK-6). Incidence of diamond has not yet been reported from these bodies. During 2001-02 inbetween NKF and WKF three new kimberlite bodies were discovered near Siddampalle village (SK-1,SK-2&SK-3) in Gadwal district,A.P. WAJRAKARUR KIMBERLITES In Wajrakarur area, three kimberlite bodies (pipes 1, 2 & 6) are found over a length of 4 km in an E-W direction. The pipe 6 occurs in black soil area whereas the rest in the residual brown soil area. KIMBERLITE PIPE 1 (WAJRAKARUR PIPE) The kimberlite reserves estimated for the southwestern part (400 x 150m) are about 6.94 Mt 75 visit: grvmalaikalam.blogspot.in upto 60m depth with a diamond resource of 52,000 ct. Though the average incidence is less, large majority of diamonds in general are gem quality and diamonds upto 9.45 ct were recovered. KIMBERLITE PIPE-6 (WAJRAKARUR WEST PIPE) Location: About 1.5 km west of Wajrararur and 300m north of Kottakunta tank. Dimension: 260 x 240m – roughly circular in shape Drilling: 19 boreholes. Deepest borehole upto 280m depth. The body is completely covered under 1.5m thick black soil. Yellow ground occurs upto a depth of 45m, followed by blue ground which extends beyond 280m depth. A granite– kimberlite breccia raft (170m long and 30-80m wide) is found in the centre of the pipe extending upto 35 to 40m depth. The kimberlite resources estimated upto 60m depth are of the order of 5.99 Mt with a diamond resource of 40,000 ct. KIMBERLITE PIPE -2 (WAJRAKARUR EAST PIPE) Location: About 2.5 km east of Wajrakarur; Dimension: 380 x 70m Drilling: 11 boreholes,Unaltered kimberlite at surface The pipe is diamondiferous. Three diamonds were recovered after processing 278 tonnes of kimberlitic material. Diamonds are of gem variety and range of weight is 0.04 to 3.26 ct. LATTAVARAM KIMBERLITES Four kimberlites (pipes 3, 4,8 and 9) are located in a radius of 0.5 km., about 1 to 1.5km east of Lattavaram (14055': 77017'; 57F/5). Outcrops are scanty. The results of exploration are as follows: Pipe No. 3: Diamond incidence(cpht)- 0.28 Pipe No. 4: Diamond incidence(cpht)- 0.25 Pipe No. 8: Diamond incidence(cpht)- 0.33 Pipe No. 9: Diamond incidence(cpht)- 0.5 KIMBERLITE PIPE -5 (MULIGIRIPALLE PIPE) Location: About 1.5 km east of Muligiripalle Dimension: 240 x 45m Sampling Five bulk sample pits ( 3 x 2 x 10m each). 276 cum of excavation, 482t of processing. No diamonds recovered. KIMBERLITE DYKE – 7 (VENKATAMPALLE KIMBERLITE) Location: About 0.5 km east of Venkatampalle (14056:77021'; 57F/5) Dimension: 1.2 km long x 0.5 to 30m wide – dyke like body. 76 78 Dimension: 143m long x 82m wide Bean shaped Pipe no. In the pipes 1& 6.5m kimberlite calcretre. Pipe no. –P 10 Diamond recovery No/Wt. Emplaced into the younger granitoids at the intersection of the ENE –WSW fracture with the major NW-SE trending Singanamala fault. covered by 1. Diamond characteristics A large majority of the diamonds recovered from the kimberlitres are gem quality.75 km west of Anumpalle village (14059' 40": 77030'55") Dimension: 1200m long x 1000m wide pod shaped body.Ct.78 KIMBERLITE PIPE – 12 (CHINTALAMPALLE KIMBERLITE) Location: 1 km west of Chintalampalle village (15002' 00": 77028' 00") Dimension: 130m long x 40m wide Pipe no. No outcrops.Ct.5 Kimberlite resources :About 0. About 14000 t of overburden over the dyke enlargement. about 90% of the diamonds by weight are gem quality and in the dyke7. rafts of granite float in the kimberlite – two linear disconnected satellite bodies noticed to the west of the main body.Diamond incidence (cpht): 44.. the pipes 1 and 6 and dyke 7 have yielded more number of diamonds.15 Diamond incidence (ct/100t): 0.in Av.48/14. –P 12 Diamond recovery No/Wt. Till now.5 Mt upto 90m depth (for the 600m length of dyke enlargements). about 60% by weight.71 KIMBERLITE PIPE –11 (DIBBSANIPALLE KIMBERLITE) Location 0..visit: grvmalaikalam. The largest diamond recovered from the area is 16.Ct. –P 11 Diamond recovery No/Wt.5 km SSE of Dibbsanipalle village (15002'00 : 77028' 00") Diamond incidence (ct/100t): 0. KIMBERLITE PIPE – 10 (ANUMPALLE KIMBERLITE) Location: 0..Nil Diamond incidence (ct/100t): Nil 77 .blogspot.30 ct by weight (from dyke-7) and is of gem variety.2/2. Diamond resources: 48000 ct upto 90m depth in the kimberlite and 4700 ct in the overburden over the dyke enlargements. visit: grvmalaikalam. west and north of the Cuddapah Basin and within the basin itself.51 ct.30 cpht. KIMBERLITE BODY CC-5 Location : This kimberlite body is located about 1km NE of Gollapalle. Toposheet no. The known source rocks tested so far are not of much economic significance and therefore intensive efforts are needed to identify additional primary host rocks for diamond.44 ct. indicating an average diamond incidence of 2. All are gems ranging in weight from 0.38 ct have been recovered from 175 tonnes material of pipe CC-5. CHIGICHERLA AREA (WKF) Coordinates: 14031': 77041'.17 ct were recovered from 88 tonnes of kimberlite material drawn from 5 trenches.Melanocratic outcrops and partly weathered and altered kimberlite capped by calcretes. Subsequently 436 tonnes of material has been processed which yielded 5 diamonds weighing 1. A.5km NE of Tummatapalle village (14049'55 : 77041' 00") Dimension: 125m long x 100m wide Emplaced into the TGA rocks along a ENE-WSW sinistral fault that displaces the Manutla dome.31 ct averaging 0. A.75km west of Golapalle Dimension: 125m x 100m.blogspot.05 to 0.2.35 cpht KIMBERLITE BODY CC-4 Location: about 1.46cpht. CHELIMA-ZANGAMRA JUPALLE AREA (NALLAMALAI FOLD BELT) A number of kimberlites/lamproites exists and lie undetected in the soil covered areas south.02 ct averaging 0. 57F/10 KIMBERLITE PIPE CC-1: Dimension: 315 x 185 m – pear shapedA grab sample of 119 t from a well dump in the body yielded 4 diamonds weighing 0.23 ct.in KIMBERLITE PIPE -13 (TUMMATAPALLE KIMBERLITE) Location: 2. nearly circular in outline Incidence of diamond: 15 diamonds weighing 2.8. the average weight of the stones being 0. 78 . KIMBERLITE BODY CC-2 Dimension 200 x 175m A total of 302 tonnes of kimberlite material was processed which yielded two diamonds weighing 1. Dimension : 220m x 70m Incidence of diamond : 6 diamonds weighing 1. 32 cpht (spot values upto 35 cpht) was recorded.24 ct 79 . Andhra Pradesh. 700 t Diamond resource : 2. in eight selected blocks in the area.NEREDUCHERLA AREA Banganapalle . along the eastern margin of Dharwar Craton (DC) in Krishna and Nalgonda district spread over an area of about 160 sq. of diamonds/weight : 167/84.visit: grvmalaikalam.9 JAGGAYYAPETA (KRISHNA) LAMPROITE FIELD (JLF/KLF) The JLF or KLF falls north of the Krishna River.5km N10W of Mallapuram Tanda. of diamonds/weight : 221/71.: 77050'-78015'. A. Kurnool district. Average diamond weight from this area is 0. six in the Munimadugu-Allahabad plateau areas and two in the Banganapalle-Rallakotturu-Lingambadi Plateau areas. B. SIDDAMPALLE KIMBERLITES During 2001-02 three new kimberlite bodies were discovered near Siddampalle village in Gadwal district.1 BANGANAPALLE . CONGLOMERATES B.26 cpht Average diamond weight : 0.50 ct Conglomerate resource : 60. 57 I/2 & E/16 Extent : 30 km long and 200 m to 2 km wide Exploration: To assess diamond potential of the conglomerates (mainly basal) exploration was carried out in 'two phases during 1980-87 by GSI in association with MECL and NMDC. mostly as clusters and run for lengths of about 1m to 400m in close association with dolerite dykes mostly emplaced along the contacts between granite gneiss and dolerite dykes.10.blogspot. Long. km. Coordinates : 15012' -15020'. The third body (SK-3) measuring 26 x 14m is exposed in a well section. The lamproites occur as 0.5m – 5m dykes.87 ct. SK-1 & SK-3 are mainly ‘hardebank’ variety while SK-2 is a concealed body with calcrete cover.38 ct Diamond incidence : 2.000 ct An average incidence of 8. The first body (SK-1) measuring 100x65m is located about 2km N25E of Siddampalle village and SK-2 measuring 110x50m is located about 1.Nereducherla. MUNIMADUGU BLOCK: No. ALLAHABAD WEST AND WEST EXTENSION BLOCKS: No.in A.Toposheet no. and comprises 25 lamproite bodies located just outside the peripheral parts of the north-eastern horn of Cuddapah basin. of diamonds/weight : 298/125. Wattipalli and Kottapalli.2 RAMALLAKOTA.67 ct Diamond incidence : 2.: 78010' – 78015' The conglomerates from both the Undutla and Cementnagar Plateau have to be tested for diamond potential. Kumool district.600 ct Of the total diamonds recovered.90 ct Diamond incidence : 2. Andhra Pradesh.visit: grvmalaikalam.LlNGAMBADI BLOCK: No of diamonds/weight : 104/51. Coordinates : 15030' –15025'.37. ALLAHABAD SOUTHWEST AND SOUTHWEST EXTENSION BLOCKS: No.000 t Diamond resource : 15.35 cpht) RALLAKOTTURU .48 cpht Average diamond weight : 0.400 ct An incidence of 8.000 t Diamond resource : 11. 8% and 16% respectively. Kimberlite specific minerals like 80 .in Diamond incidence : 1.00 t Diamond resource : 26.32 ct Conglomerate resource : 10.59 cpht Average diamond weight : 0.23 cpht was recorded over a length of 200m (with spot values upto 27.49 ct Conglomerate resource : 21.89 cpht Average diamond weight : 0. Search for kimberlite in Buthpur and Achampet block in Mahbubnagar district.3 UNDUTLA-TAMMARAJUPALLE -CEMENTNAGAR AREA Area : Undutla-Tammarajupalle-Cementnagar. yielded kimberlite specific minerals like picro-ilmenite and chrome-spinel in stream sediment samples from Palkampally. B.44.42 ct Conglomerate resource : 3.600 ct Spot values for diamond are upto 7 cpht. B.94.blogspot. gem quality constitutes about 76% while the off colour and industrials.YAMBAI AREA The erratic distribution and lensoid geometry of the conglomerate beds warrant close spaced pitting/shallow drilling to delineate the beds as well as estimate the conglomerate resources. in chrome spinel has also been recorded from Kalwakurthi and Charakunda block in Mahbubnagar and Nalgonda districts. and the present and most successful from 1947 onwards. etc. Nizam period 1886-1920. Kolar. hosts the maximum number of gold occurrences. ( 0. Mosabani. The Eastern block provides an important and favourable lithologic. Honalli.visit: grvmalaikalam. mantle derived intrusions.34 tonnes recovered from secondary source by smelting of imported copper concentrates by HINDALCO at Dahej in Bharuch dist.490 tonnes. and the remaining 10. The gold boom was experienced in India with discovery and mining in Kolar. In the northwestern Indian Shield. Hirabuddni (HGML) in Karnataka and as by product from basemetal sulphide deposits of Khetri (Rajasthan). Gadag. Pahardia. the total gold production in the year (2006-07) was 12.5 tonnes during the year 1905.blogspot. Most of the old workings were closed due to dwindling production and prevailing cost-benefits. structural and stratigraphic milieu for gold mineralization and hosts major deposits like Kolar and Hutti. Hutti. 127 kg from basemetal mines as by product.5% of world production). 1937 to 1947. gold occurs in association with copper in the Archaean 81 . The Dharwar craton. with two blocks viz the eastern and western. Bastar. of which 2. Singhbhum(Jharkhand). Uti. survived for 110 years and the Hutti gold field witnessed four periods of widely separated exploration and mining Viz. GOLD India ranked 6th in the world with a Gold production of 19. Gujarat.82 tonnes. Kundrekocha. Pre Asokan +2000 years old. in public sector and Kundrekocha in private sector in the decreasing order. Mysara. The advent of worldwide gold rushes in 19th century laid the foundation for present day mining activity.36 tonnes is from primary source. Lawa. Kolar mine has produced more than 800 tonnes of gold before its closure in 2001. Gold occurs in a variety of litho assemblages. prominent granite greenstone belts of Peninsular Sheild are located in Dharwar. whereas the production of gold from primary source during the year 2007 is only 2. diaperic juvenile plutons and granulites. in the South and a few in North viz. The deepest (about 250m in length and over 195m in depth) known old working in the world is located on the Main reef at Hutti gold mines. In the Indian subcontinent. Geochronological data of gold metallogeny revealed major periods of enrichment as Archaean and Proterozoic. Wynad. Singhbhum and Rajasthan cratons. and multiple geological environments / settings such as greenstone belts. Presently gold is produced from three mines viz Hutti. In India. Ramagiri. the second deepest (3200 m) gold mine in the world. .65 Mt of ore with an average grade of 4.In Bisanattam Block. There are two zones of subparallel lodes. confined to shear zones.05m was estimated. the gold mineralisation associated with the greenstone belts is quite significant. In Mallappakonda Block.19 Mt with grade ranging from 4. Puga geothermal system is a “hot spring” type epithermal gold deposit in the making. Nundydoorg.22 g/t of Au over widths ranging from 1.The deposits are vein type with wall rock alteration. Mallappakonda.A reserve of 4. auriferous zones associated with BIF are lensoid. in Mangalwar Complex) and Proterozoic metavolcanosediments (at Bhukia and Dugocha. the primary gold mineralisation is recorded in three different geological settings viz. Kudithinapalle and Avulathinapalle. especially in the eastern part of the belt. Mysore and Bisanattam mines is located in the central part of the 80 km long Kolar Schist Belt.in greenstone-like sequence (at Dhani Basri.(i) Archaean greenstone belts similar to Dharwar Craton. it became an insignificant gold producer with grades lowered to about 3-4 gms/t to about one tonne per annum in the mine. the Champion lode on the east and on the west the Oriental and McTaggert lode. Gold also occurs in Palaeo / recent river alluvium placers.Gold-polysulphide association were identified in Champion Reef and gold-pyrrhotite-arsenopyrite in McTagart lode with characteristic scheelite. sub-conformable to the meta-basite host rock viz.The economical values of gold ore in the southern end of the Kolar Schist Belt came into limelight at the time the KGF values were uneconomical to mine and is marked by a number of old workings. in the Ladakh region of Jammu and Kashmir. both GSI and MECL carried out investigations for gold. The mineralized zones found in fissile amphibolite are lensoid. From the position of a large producer in the world (790 tonnes since 1880 from a grade of about 16 gms/t). The deposit is under exploitation by the BGML.2 to 5. laterite.A reserve of 0. Bisanattam.The KGF comprising the Champion.3 g/t was established.Gold mineralization in the southern belt was established by GSI at Chigargunta.blogspot.The Chigargunta mineralization in the south is in non-conformance with that of the KGF to the north and is in distinct tectonised zones and post-dates the major folding and amphibolite grade metamorphism. (ii) in Banded Iron Formations (BIF) and amphibolite associated with granulites and (iii) in quartz-carbonate veins related to alkaline magmatism. in Aravalli Supergroup) with enrichment in the latter. Kolar Gold Fields (KGF) had been the primary gold producer in the country. Among these.visit: grvmalaikalam.The 3 km long mineralized zone occurs in the amphibolite and Champion Gneiss units as well as on their contacts. parallel and en-echelon in disposition and vary in width from 1 to 3 82 . parallel and enechelon occurring over a strike lenth of 400m. soil and regolith.46 to 12. In SGT. In Veppananpalli sector. All the known gold bearing lodes are confined to the western limb of an overturned syncline over a strike lenth of 15 km. chalcopyrite.57 g/t with an average width of 1. gold mineralisation has been recorded in the amphibolite band occurring within the gneisses. gold mineralization is localized along the shear zones developed parallel/subparallel to S1 schistosity in both basic and acid meta-volcanic rocks.blogspot. pyrrhotite. In this block. pyrite.2 to 2.96 g/t. the southern continuity of the Kolar schist belt is traceable as two narrow linear strips. located 3 km south of Bisanattam Mine. Gold is associated with sulphides. In the Maharajagadai block. Near Bargur (15 km SE of Maharajagadai block). proving sizeable gold reserves. gold is associated with pyrite.13 Mt of ore with a grade of 5. eleven zones of gold mineralisation have been delineated within the silicified zones in quartz-sericite schist (Champion gneiss) occurring in association with amphibolite. Extensive and detailed investigations were carried out by GSI in Hutti mines area.2 g/t was established. gold mineralisation is confined to sheared and silicified zone in amphibolite and associated BIF.2 to 0. The mineralisation is traceable for a strike length of about 75 m over a width of 0. The surface exploration.in m. sphalerite.48 Mt ore with an average grade of 1. Molybdenum is also found in the quartz veins. In the Adakonda Block. Gold mineralisation is reported in the southern extension of the Kolar schist belt in Veppananpalli and Bargur sectors in Krishnagiri district of Tamil Nadu. viz.1 g/t was established.The Hutti Gold Mines located in the northern part of the belt produced 1048 Kg of gold during 1990-91. About 0. In the Hutti-Maski Schist Belt. viz. pyrrhotite. ancient workings and mines are seen over an area of 200 km2.07 million tonnes of ore with 1 to 2 g/t of gold upto 75 m vertical depth. Wandalli. the eastern Maharajagadai strip and the western Adakonda strip representing synformal keels. The epigenetic gold mineralisation is mainly confined to the sheared and silicified zones in the quartz-sericite schist.In Kudithinapalle Block.The deposit was mined by BGML and since been closed.The prospects explored by GSI are-(i) Western 83 . A reserve of 0. by trenching and groove sampling. gold mineralization in quartz reefs is hosted by both hornblende schist and Champion Gneiss. has indicated gold values ranging from 0. arsenopyrite and chalcopyrite. In the Gadag Gold Fields of Chitradurga district.65 to 4. Uti. arsenopyrite and galena of which pyrite is the most dominant.45 m with gold assay values ranging from 0. Exploratory drilling in this block has indicated a potential reserve of 0. The quartz reef is about 100m long and 2 to 3 m wide.visit: grvmalaikalam. Hira-Buddini and Maski.5 m over a strike length of 450 m. Karnataka. In Ajjanahalli block-F.blogspot.21 m upto 75 m depth for the main lode and 0. Band-II (strike length 200m average width of 2m) has recorded 0. gold mineralization is also known from the area north of Nagavi hosted in BIF in contact with tuffaceous rocks. (ii) Middle Group comprising Kabuliyatkatti-Attikatti.56 m and gold content ranging from 1.03 to 0. Karnataka on. three major auriferous BIF bands have been delineated.28 to 1. Another prominent area of gold mineralisation is located in Wynad gold field in DevalaPandalur. A reserve of 0. north of this mine.023 Mt of ore with an average grade of 4. Analysis of trench samples indicated gold value ranging from 0.10 g/t to 4.visit: grvmalaikalam. 84 .39 g/t. Ancient mining activity is recorded in both the fields. In Kottapalle Block.70g/t. Mysore Mine and Sangli Mine.36 Mt with 2. 10 parallel zones of mineralization localized in shear zones in sulphidic BIF along a fold have been delineated by GSI. a probable reserve of 0. preliminary exploration has led to estimation of 0. hosted mostly in greywacke.29 to 1. hosted in greywacke.0 g/t. Band-I (strike length 300m average width 3 to 4m) has recorded 1. In the Anesidri-Ajjanahalli-Bellara area.07 Mt of ore upto a maximum depth of 70 m for 4 lodes over width varying from 1.41 m was estimated upto 165 m depth. In Ramapuram area. The Ramagiri-Penakacherla Schist Belt extends over a strike lenth of 100 km with number of gold prospects grouped into two fields viz. gold mineralization is associated with meta-volcanics as well as sulphide banded iron formation of the Chitradurga Group. Tumkur district. The estimated reserves at 0.bedrock samples yielded gold value ranging from 0.22 g/t. In addition. Very recent exploration for gold by GSI in Ajjanahalli Block-C.00 m upto 80 m depth for the northern lode has been estimated.2 g/t gold.7 Mt with an average grade of 7 g/t in the Om Pratima-Gantalappa Block.34 g/t of gold over a width of 1. Cherambadi and Kotagiri sectors in Nilgiri district of Tamil Nadu and in the adjoining parts of Kerala.in Group comprising Hosur-Champion.5 g/t cut-off grade are 0.11 Mt withan average grade of 2.70 g/t gold. Yelishirur and Venkatapur mines hosted dominantly in metabasalts and meta-andesites. Tumkur district.28 to 1. The strike lenth of the block is about 1500 m. RGF has a reserve of 0. Auriferous lodes of BGF are of small length.65 g/t over an average width of 1.13 g/t of Au over an average width of 1.02 to 2. Band III (strike length of 700m average width 4m) has recorded gold values from 0.77 Mt of ore.and (iii) Eastern Group comprising Sankatodak Block and a fewer prospects east of Nabhapur and Kabuliyatkatti villages. In the Ajjanahalli block.36 g/t to 6. (1) Ramagiri Gold Field (RGF) and (2) Bhadrampalle Gold Field (BGF). 5 km with a width of 2 m. Auriferous quartz veins occur in sheared biotite gneiss showing intense sericitisation.visit: grvmalaikalam. Nadghani.98 g/t. The host rocks for these quartz veins are biotite gneiss with interbanded hornblende granulite and magnetite quartzite. The gold-bearing quartz reefs show a general trend of N-S. Solomon and Hare Wood mines near Devala and Phoenix. Preliminary sampling by GSI in the year 1967. three quartz reefs are exposed.8 km has been traced.9 to 6. The width of the individual quartz reefs varies from 20 cm to 5 m and traceable for a length of about 60m. gold mineralisation is confined to zones of intense shearing and dislocation which have acted as loci for emplacement of auriferous quartz veins. Samples collected from this sector have analysed gold content of 3. This shows NE-SW trend with southeasterly dip in the southern part and N-S trend with 60º dip towards east in the northern part. Duraiswamikaradu. two quartz veins are exposed.41 g/t from 61 samples with 18. In Mangorange tea estate. The other reef is measuring 100 m x 2 m.in In Devala-Pandalur sector. Among these two reefs. The first one occurring in the form of two detached en-echelon reefs trending in E-W direction with 25 to 30º dip towards north.2 km with width varying from 1 to 3 m. In Duraiswamikaradu area. Two main types of gold mineralisation have been recognised – one is sulphide-rich and the other is sulphide-poor type. In Hare Wood mine. the lode is having a width of 2 to 5 m for a limited strike length of 40 to 60 m with grade varying from 1. Gold occurrences and ancient mining activities are also reported from Adathurai-Kotagiri sector located in the eastern part of the Nilgiri hill ranges in Tamil Nadu. the gold mineralised zone is traceable for a strike length of about 1000 m over a width of 1 to 3 m with an average tenor of 1. Subsequent detailed studies by GSI (2004-06) have brought out that the Adathurai area is traversed by a major brittle-ductile shear 85 .blogspot.2 g/t. drives and trenches has indicated an average gold value of 2. In Went Worth-I & II old workings.04 g/t. the prominent one is having a strike length of over 1. The exploratory drilling carried out in some of the old working areas reveal that in Alpha-Victoria mine. In Cherambadi sector several old workings for gold are located in Mangorange. Another quartz vein has been traced for a strike length of 1. The gold mineralisation is associated with intense wall rock alteration in the form of sericitisation and chloritisation. Alpha-Victoria. Went worth-I & II and Cherangode. a quartz reef with a thickness of 1 to 3 m over a strike length of 0. the maximum strike length and width of the lode are 116 m and 30 m respectively.3 g/t being the highest value. Rosedall and Glenrock mines near Pandalur are the important old workings located in this sector. from the old inclines.06 to 15. The gold assay values of the samples collected from this sector are not encouraging. In Solomon mine. forming the eastern extension of Attappadi valley in Kerala. In Kottathara block of Attapadi valley. These lithounits show intense shearing marked by cataclasites.visit: grvmalaikalam. This prospect falls within the Gopanari Reserved Forest area.5 m width in two profiles.03 to 3. where gold is found in quartz reefs. Preliminary sampling by GSI has indicated gold values from 0. Kerala. Old workings for gold are also recorded in Bensibetta-Modikadavur -Inbakombai sector in parts of Erode and Coimbatore districts. Similarly. The quartz vein contains sulphides which are mostly pyrite and subordinate arsenopyrite. Auriferous quartz veins are found within the sheared granitic gneisses which occur in association with charnockite.2 g/t over 1. The quartz veins occur as small stringers as well as thick veins having a maximum width of about 5 m over 150 m length.5 m width and 6. the samples collected from an gold incline have analysed a maximum gold value of 22. A total of five zones of gold mineralisation represented by lensoid auriferous quartz veins have been delineated.in trending N-S to NNE-SSW. emplacement of auriferous quartz veins is noticed.5 km. Limonitistion is seen along the fracture planes. Samples collected from the auriferous quartz veins have shown gold values ranging from 0. gold minerlaisation is reported within the fractured and sheared quartz veins emplaced along minor shears developed close to the major Bhavani Shear Zone. Four first level boreholes drilled in this zone have indicated the depth persistence of the gold mineralised zone at 50 m vertical depth. All along the shear / fracture planes.1 to 0.blogspot. 60000 tonnes of gold ore with an average grade of 13. Palaghat district. Placer deposits of gold are known from Nilambur valley in Malappuram district. mylonites and phyllonites.6 g/t has been established. In Gopanari-Velliyankadi sector in Coimbatore district.5 g/t.9 g/t thereby indicating than this zone is a promising one for gold mineralisation.8 g/t. Although the assay values obtained for the core samples by AAS are not encouraging.26 g/t over 2. pyroxene granulite and minor meta-sedimentaries of Sathyamangalam Group. Wynad gold field is one of the earliest known gold fields in the country. selected samples analysed by Fire assay method have indicated gold values upto 5. 86 In Maruda area of . The general trend of the quartz veins varies from NE-SW to ENE-WSW and occasionally along NNW-SSE to NW-SE directions.8 g/t. These zones vary in length from 7 to 13. Chemical analysis of the trench samples collected from this zone shows an average gold values of 2. Preliminary exploration carried out by GSI by test drilling has indicated six parallel lensoid zones in en echelon pattern in Kappil prospect and two lensoid lode zones in Mankada prospect. Thavingal.5 ppm. of ore with a gold content of 1726 kg in Kappil prospect.visit: grvmalaikalam. magnetite-orthopyroxene bearing quartzite (silicate phase) to silicified sulphide rich quartzite (sulphide phase).462 m.28 to 4.55 million tonnes of primary gold ore with an average grade of 4 g/t over a strike length of 350 m upto a depth of 100 m has been worked out by KMEDP.58 ppm and preliminary estimate indicate 0. A structurally controlled mineralised zone with an average width of 1. preliminary gold occurrences are also known in Meppadi.75 m has been traced with a value of 7. brecciation and minor drag folds. Kuthimada. Preliminary prospecting of the BIF occurring in Melchengam-Attipadi-Thirthamalai belts and in Vediappanmalai-Kavuthimalai-Uchchimalai areas of Tiruvannamalai district has indicated gold values ranging from < 0. Venmani.28 to 0.6 g/t. Karumsanthod. Rasipuram. Chundale. 87 . These BIF show intense shearing.t.6. Tiruvannamalai. Besides. Samples collected from Kannakadu Malai and east of Ravathanallur in Villupuram district have assay gold values ranging from 0.3 g/t gold. Tariode. Vattam. Kariyampatti and other areas have analysed 0. The BIF shows transition from quartzite (oxide phase).1 to 0. ii) Gold mineralisation associated with Archaean BIF in granulite terrain Numerous bands of Banded Iron Formation (BIF) occur in association with charnockite and pyroxene granulite within the granulite terrain in northern Tamil Nadu in parts of Dharmapuri.9 g/t of gold. Idaiyappatti. Gold bearing quartz veins occupy the shear zones and fracture / foliation planes within the BIF. North Arcot.in Malappuram district.The samples collected from the BIF of Nainar Malai. Vayittiri. Gold mineralisation is restricted to the highly sheared and fractured quartz vein within the biotite-hornblende gneiss and amphibolite.blogspot. The tenor of gold bearing reefs in Wynad Gold fields is generally 2 to 3 g/t. The grade of the mineralisation in Kappil prospect ranges from 1. are estimated reserve of 0. Villupuram and Salem districts. Gold mineralisation has been reported by GSI in epigenetic quartz veins emplaced within amphibolite / granite gneiss in Puttumala in Attapadi valley in Palakkad district.1 to 0. Kakkarikunnu and Manathoddy areas of Wynad district in Kerala. 09 g/t. In Elavadi area.8 g/t and five samples giving 0. In Vellakkal west area.11 to 0.visit: grvmalaikalam. hydrothermal alteration of the charnockite and the associated quartzofeldspathic gneiss with profuse development of epidote and carbonates and emplacement of several quartz veins. The prominent among them are in Nekkundi area near Vaniyambadi and in Andipatti-Elavadai-Ammapettai and Vellakkal west sectors within the Harur-Uttangarai molybdenum belt in Dharmapuri district. The remaining samples have shown < 0. The major quartz vein trending in NE-SW direction is traceable for a strike length of about 1 km with a width varying from 1 to 20 m. two samples have analysed 2.05 to 1.03 g/t of gold.35 g/t with sporadic high values upto 10 g/t. six samples have analysed 1. Out of 62 groove samples. fifteen samples showing gold values from 0.in The available data indicate that gold mineralisation in BIF is sporadic and the higher values of gold are mainly from the silicified zone in BIF. only three samples have 88 . five samples have analysed 1. It shows intense shearing and wall rock alteration.03 to 0.25 g/t of Au. The HarurUttangarai molybdenum prospect is located within this shear zone. Out of 87 groove samples collected from this vein. iii) Gold mineralisation associated with Neoproterozoic alkaline-carbonatite complex In northern part of Tamil Nadu. eighteen samples have analysed 0. A few occurrences of gold are reported in the quartz veins as well as in the ankeritesiderite bearing quartzofeldspathic gneiss within this shear zone.15 g/t of gold.3 g/t. 5 to 27 m.1 to 5 g/t of gold and six samples analysed from 0.10 g/t of gold. a feebly carbonated quartz vein is traced for a strike length of 800 m with width varying from 5 to 15 m. Chip samples collected from the sheared quartz vein with perthosite have analysed gold values ranging from 01.2 to 0. This zone is marked by intense shearing. a major quartz vein is traced for a strike length of 600 m with width varying from.13 to 0.3 g/t. In Nekkundi area.04 to 0. an array of alkaline-carbonatite complexes is found within the major NNE-SSW trending Dharmapuri shear zone. the auriferous quartz vein is 1 km long and 4 to 12 km wide trending in N20ºW-S20ºE to N-S.73 g/t and six samples analysed 0. In Andipatti area. gold mineralisation occurs in the quartz veins emplaced within the sheared epidote-hornblende gneiss containing quartz-carbonate and ultrapotassic veins. Out of 117 groove samples collected from this quartz vein.4 km long quartz vein traced in Ammapettai area shows a general trend of N20ºES20ºW with 20º to 40º dip towards southeast.46 to 3. The 1. The remaining samples have shown gold values <0.blogspot. Out of 42 groove samples collected from the entire length of the quartz vein. The width of the quartz vein is 5 to 17 m. to 4. On the basis of analytical result a resource of 22. The stage of exploration corresponds to G-3 of UNFC system. Au mineralization of Gulaldih :Extensive old workings occur over a strike length of about 10 km from Gulaldih Detailed geological mapping and examination of old workings have revealed presence of a N85°W-S85°E trending shear zone in the volcanosedimentary sequence of Agori Formation.40 m to 2.97million tonnes of gold ore with 1. Twenty seven samples have shown gold values ranging from 0.81 g/t Au has been estimated in Delwara West block. the sheared quartz vein have analysed 0. copper.03 g/t of gold. The prospect is divided into Bhiwa and Gulaldih block.0 m.2 to 1. Rajasthan by GSI. The stage of exploration corresponds to G-3 of UNFC system. etc. Gossan zones are well developed and are marked by boxwork with limonitic coatings. Uttar Pradesh.visit: grvmalaikalam. 89 . and from associated copper ores of the Khetri copper belt. Chemical analyses of samples have analysed gold upto 3. Veppanapalli area in Dharmapuri district and in Arakkadavu-Gudaiyur-Velliyankadu-Bhavanisagar sector in Coimbatore and Erode districts. placer gold is reported from several parts of Tamil Nadu in Singiliyankombai and Iswaramurthipalaiyam area in Salem district.3 ppm. In Velampatti block. The northern zone extends for about 2. Five parallel zones extending over a strike length of 2 km is delineated.0 g/t of gold in association with molybdenum in several boreholes drilled upto 320 m vertical depth.03 to 0.blogspot. iron.58 million tonnes to 83.3 ppm and threshold value of 1. Besides.87g/t Au. which is about 20 km long. the shear zones occur in two sub parallel zones in Agori Formation.55 million tonnes with average grade of 1.0 m The southern zone is in arenaceous phyllite with width varying from 0.in analysed 1. The mineralisation occurs in the quartz veins and is associated with sulphides of lead. Besides these primary gold occurrences. Ladera area (Jaipur district). Primary gold prospects occur in shield areas of Uttar Pradesh in Lalitpur and Sonbhadra districts. The total gold resource of Bhukia gold prospect has been augmented from 60. the major reserves of gold are from the Jagpura-Bhukia belt in Banswara district of Rajasthan.053 million tonnes gold ore with an average grade of 3.08 g/t and the rest of the samples give only < 0.Prospecting by Geological Servey of India in Bhiwa block indicated that.87 ppm with background value of 0. gold is also noted to occur in Pindwara-Watera belt. Minor occurrences are noted in Hinglaz Mata area (Dungarpur district). A tentative resource of 0. Clusters of quartz veins form detached lenticular bodies.0 g/t of gold.39 to 3. Sonbhadra district.30 m to 2. In the Proterozoic metavolcanosediments of the northwestern Indian Shield.03 g/t Au has been estimated in the Proterozoic rocks of Sonapahari area.4 km with width varying from 0. 11 million tonnes of 3. Among the important areas Kunderkocha deposit is considered to be highly potential. Bhitardari and Digarsai.62 million tonnes of 1.5 g/t). BIF hosted gold deposits of Sonadehi.306 to 0. The average grade of gold revealed from matrix-supported QPC bands of Haludbani sector is around 0. Gold occurs in these ores as discrete grains.in The known gold deposits of the Central Indian Shield includes Sleemnabad in Jabalpur MP.Reserve of gold in Kunderkocha as on 1.Porapahar Shear Zone traversing 90 .84 g/t Au (at cut off 3 g/t). In the Eastern Indian craton. Kitari-Marupar deposits of Nagpur district. Sausal. The stage of exploration corresponds to G-3 of UNFC system.28 g/t and 0.4. revealed a resource of 2. gold is reported from a number of places located to the north and south of Dalma range.visit: grvmalaikalam. . Ankua. ln north Singhbhum.25 mt with 3.699 g/t gold.Recently the intensely fractured quartzite underlying the Dhanjori volcanics and the quartz pebble conglomerate (QPC) have shown significant gold values. At Parasi work by Geological Survey of India revealed an estimated gold resources of 0. Another prospective area is the Tomka -Daitari region. At Pahardia a gold ore resource of 0. Auriferous quartz reefs are commonly found in the low-grade metasediments and metavolcanic rocks of ultramafic to acidic composition belonging to Iron ore Group and Singhbhum Group and volcanics of Dhanjori-Dalma affinities.66 g/t Au respectively.5 tonnes of yellow metal. The other notable occurrences in this area are Pahardia. Sausal.This is likely to yield of 4. Rungikocha. Investigation for gold mineralization in Sonadehi gold prospect Chhattisgarh.6 million tonnes of 1. Bastar district.28 million tonnes with 0.83 g/t Au (at cut off 1 g/t) and 1. one of the important metallogenic provinces of India.The estimated gold resources of the region is of the order of 2. Decades back gold was mined from Lawa and Mysera.85 g/t gold at 1 ppm Au cut off has been estimated up to 65m vertical depth. Chaibasa Formation forming the lower part of the Proterozoic Singhbhum Mobile Belt hosts occurrences of gold at Pahardia.1990 was 0. The bulk sample from Haludbani and Baruniya revealed 1. Ankua. Primary gold mineralization in reef quartz is noted intersecting pelitic and volcanic sedimentary sequences at Babaikundi and Birgaon along Tamar.blogspot. Pandripani deposit of Raigharh district Chhatisgarh .75 g/t. The LawaMaysara deposits and quartz-pebble-conglomerate located at the base of Dhanjori basin is equally potential in view of its multi-metal association in the latter. gold is obtained as important by-product during the extraction of copper (and other elements) from the copper ores of the Singhbhum copper-uranium belt. south of the Jamda . 0. The one at Sonapet is also quite significant. north of the Dalmas.07 g/t Au (at cut off 0.1 ton. Maharashtra. Parsori West.Koira valley.69mt. Ltd. The placers presumably have been derived from auriferous quartz veins in the metamorphic rocks of northeastern Himalaya. Andhra Pradesh. in the Singhbhum Copper Belt. especially in Keonjhar disrtict adjoining Bihar.blogspot. Occurrences of native placer gold have been recorded from a few places in rivers of Upper Assam. Madhya Pradesh. In view of insignificant quantity of gold. in Himalayan region and in the Darjeeling Himalaya.68 g/cu. Small grains of native gold were won by panning alluvial sand. Gold has been traditionally obtained from the sands of the rivers and streams of southern Chhotanagpur.m in gravel. Alluvial gold in Sonapet valley of Ranchi district varies from 0.4 million tonnes with a maximum tenor of 20 ppb. in Malanjkhand. Presence of sporadic gold placers..0m. Lalitpur. Kargil and Doda districts. lead. Placer gold has been reported from Bijnor. is not possible. 91 .visit: grvmalaikalam. Morabad distts of U. Gonda. Placer gold is also known from Ankua. in Sargipalli. Sundergarh district. traces of silver and platinum are reported from Kupwara. commercial exploitation of gold. Bihar. BASE METALS The major discoveries of copper.54 g/t with thickness varying from 0. one at Ingaldhalu located in the Chitradurga schist belt and the other at Kalyadi located in Dharwar schist enclave within the Peninsular Gneissic Complex of Karnataka are being worked on a scale of about 200 tonnes per day by the Chitradurga Copper Company which is a subsidiary of the Hutti Gold Mines Co. in the Cuddapah basin. Auriferous quartz vein extending for about 500m shows gold values from 0.88 Mt (IBM. One placer sediment near ichagarh and another 1. Occurrence of alluvial gold has been recorded in almost all the districts of Orissa and panning of the stream sediments in the major rivers has yielded gold. Recoverable resource of gold in Bihar & Jharkhand has been estimated to be 128.15 to 3. zinc deposits of India are in Khetri Copper Belt and in the Dariba-Rajpura area in the Aravalli Supergroup of rocks in southern Rajasthan. Jammu & Kashmir.Orissa. Estimated tonnage of gold from placer along Sona nala and Karkari nala are about 0.P and Nainital & Pauri Garhwal districts of Uttarakhand. though there is evidence of old mining activity in the northern parts of Orissa. 2005).045-0.Potential occurrences are summarized tectonic betlwise: Deposits/Occurrences in Dharwar Craton: Two small deposits. Gold occurrences of Orissa are confined to mainly placers.in Chhotanagpur Gneissic Complex.5 km south of Ichagarh indicated 1200 ppb and 555 ppb of gold respectively.30 to 1. Leh. of which the Subansiri riverbed was the best gold producing area in Assam in older days. Copper mineralisation is prominent in the Belligudda-IngaldhaluKunchiganahalu sector over a strike length of about 5 km.. Ingaldhalu South Block . The mines of the Chitradurga Copper Company are located in the Mine block and the North block.3 km. near G. zinc. Ingaldhalu North block .Ingaldhalu-Kunchiganahalu sector. Ingaldhalu North/West Block . pyrrhotite. 57 B/8) copper deposit which is now being mined by the Chitradurga Copper Company is located in the Belligudda.4 million tonnes with a copper content of 1. this sector has been divided into 5 blocks.strike length about 1. The sulphide mineralisation is localised in quartz veins occupying narrow shear zones in the metabasalts and is of polymetallic type containing copper. lead. Ingaldhalu copper deposit. arsenic. Pyrite mineralisation with galena and occasional quartz veins is seen in chert bands and quartz reefs occurring within the metavolcanics.strike length about 1.in A belt of polymetallic sulphide mineralisation with copper. In addition.strike length about 1.visit: grvmalaikalam.R. (from south to north) viz. Copper mineralisation mostly occurs in quartz veins emplaced along shear zones occurring within the metavolcanics. This mineralised belt (designated as the Chitradurga sulphide belt) extends from Chikkanahalli (14°26: 76°22') in the north to Yarahalli (14°04: 76°26') in the south. The principal sulphide minerals are chalcopyrite. Mines block . Government of Karnataka.2% of 92 . pyrite and sphalerite with minor galena. This sector has been explored in detail by the GSI and the DUG.Halli-Chikkananahalli stretch (about 16 km). The Mines block has been explored by 45 boreholes drilled by GSI and the Department of Mines and Geology. antimony. antimony.strike length about 260 m. For purposes of exploration. Halli. Galena mineralisation with silver values is seen in the Kurubamaradikere-Madikeripura area over a length of 10 km. Mine development has been done to a vertical depth of about 300 m in 12 levels.R. arsenic.8 km . the reserves in the Mine block have been estimated to be 1.1 km . gold and silver values has been traced over a strike length of about 40 km along the eastern part of the Chitradurga Schist Belt.On the basis of the borehole data.blogspot.strike length about 750 m and Ingaldhalu Northeast block . Galena occurrences have also been reported further to the north. and gold mineralisation occur along the Gonur-G. Chitradurga district: The Ingaldhalu (14°11': 76°27'. zinc and lead with some silver and gold values. Appreciable zinc and lead are also present in the mineralised zone. The overall pattern of the distribution of copper.35 to 3. On the whole.16 million tonnes with a copper content of 1. The total strike length of the block is 1. The grade ranges from 0. copper with minor lead and zinc in the central part with the zinc and lead contents increasing laterally both towards south and north of the Ingaldhalu Mines block. The copper lodes range in width from 0.3 to 9%.14 to 3. lead and zinc values indicate zoning of the metals.blogspot.314. The cumulative strike length of the 4 zones is about 1380 m. mostly around 1%.3 m. The mineralised zone does not appear to persist to deeper levels. Zinc ranges from 0.38%.330 tonnes. the gold and 93 .5% and the mineralised zones are very narrow.25% Cu. The copper content in the sulphide zones vary between 0.53% Apart from these.35 to 1. copper mineralisation has been traced over a strike l length of about 750 m. Significant concentrations (>0. Ingaldhalu North block : This block has been investigated by 24 boreholes drilled by GSI.visit: grvmalaikalam.36 m) and copper content from 0.On the basis of borehole data.46% has been estimated for this block over a strike length of 450 m and a vertical depth of 120 m.5 to 1. The silver values in the ore mined ranges from 6 to 85 g/t with occasional higher values of upto 950 ppm. generally between 2 and 6%. (mostly less than 1 m). the reserves estimated in this block are as follows : Indicated .31 g/t silver. The width of this zone ranges upto 1. Ingaldhalu North West block :This block lies in the area intervening between the Mines block and the North block and has been explored by 37 boreholes drilled by GSI.150 tonnes with 0.1 to 0. The width of these zones range from 0. Ingaldhalu South block :In this block.5% copper) are confined to 4 discontinuous zones varying in length from 70 to 440 m.and lead from 0. a parallel mineralised zone has also been established over a strike length of about 350 m.77. The reserves estimated in this block are of the order of 0.5 and 2%.32 to 10%. The gold content is generally between 0.03 m (average 1.Reserves have not been estimated from this block.75 to 2. Total = 391.77%.95% Copper and 9.A reserve of about 0.55 m and copper content ranges from 0.8 km. Inferred .27 million tonnes have been blocked out by the mine development. Ingaldhalu North-east block : the copper content varies from 1. The mineralisation is similar to that in the Mines block.180 tonnes with 0.95% Copper and 9.22 million tonnes with an average copper content of 1.31 g/t silver.2 g/t with occasional values upto 3 to 5 g/t.79%.44 to 4. since the average copper content is <0.1 and 2.2%. generally between 0.in which about 0. it can be stated that geochemical sampling and geological work carried out in various parts of the 40 km long Chitradurga sulphide belt has identified a few small deposits over a 94 ..30% zinc coinciding with I. Kennedlu Southeast block (14°07'45'': 76°30').16% -0. malachite and cervantite and indicated multi-elemental anomalies (for lead.2% zinc. 0. arsenic and silver) scattered over an area of about 2. pyrite. 3-5% copper and 2% zinc.Geochemical sampling has indicated anomalous zones with values upto 0. Summing up. Three shallow boreholes intersected only narrow.antimony.galena. Musturu (14°28': 76°26'). lean zones of copper. viz. The quartz veins traversing acid and maficvolcanics have analysed 0.in silver contents of the mineralised zones in the Belligudda-Ingaldhalu-Kunchiganahalu sector are also quite high.0.. anomaly zones indicated by geophysical survey. 0. R. Chitradurga district : In this block. if the recoveries of gold. G. regional geochemical surveys have indicated high values of copper.50 to 1.62% Sb and upto 410 ppm silver and 0. lead and zinc viz.3% Pb.Kunchiganahalu (14°12': 76°27'). 3. The economic viability of the Ingaldhalu operations can be improved marginally. 0. chalcopyrite. silver and zinc associated with the ores can be substantially increased from the present level of less than 50%.km.90 m with 0.visit: grvmalaikalam.66% copper and 0. Chitradurga district: Geochemical sampling identified a few parallel en echelon quartz veins showing intense shearing and presence of sulphides such as chalcopyrite. Chitradurga district : Two brecciated quartzose/cherty zones (250 to 800 m) within the Peninsular Gneissic Complex contain disseminations of sulphides.5 sq.11 to 10. A few scout boreholes are being drilled in this block to evaluate the anomalies.52% Zn and 0.2 g/t gold and 950 g/t silver.P.blogspot. copper. galena and sphalerite. zinc.88% arsenic. Madikeripura (14°13'30'': 76°26'30'') . Some boreholes core samples have indicated upto 12. sphalerite and stibnite. This anomalous zone is also proposed to be evaluated by drilling.34 . lead and zinc in rock samples.6% Cu.11 . Samples of quartz veins have analysed upto 12% lead.1. Scout drilling to evaluate the anomaly is in progress.14% Cu. Halli Northwest block (14°16': 76°25'): This block is located in the northern part of the Chitradurga Sulphide Belt with a well marked shear zone trending NW-SE over a strike length of about1 km. 0.2 g/t gold. Copper mineralisation is associated with vein quartz and pegmatites intruding the amphibolites and mica schists. pyrite and chalcopyrite associated with vein quartz and pegmatites in mica schists and amphibolites have been reported from a number of locations -in Nellore District. Jonnagiri (15°44': 77°31' .blogspot. The possibility of finding deposits located distally in the overlying metasedimentaries is to be critically evaluated.24 m. The overall geological setting and indications of mineralisation warrant further detailed work in the other parts of the 40 km long Chitradurga sulphide belt and its possible extensions towards north and south.45 m thickness averaging 0. The rocks trend NW-SE with steep dips (55 to 75°) towards south-west.5%.12% over a width of 5. Sandur taluk.3% sulphur are estimated down to a depth of 100 m. granites.9 million tonnes of pyrite ore with 2. Out of 10 boreholes drilled in the area. Sporadic occurrences of malachite.visit: grvmalaikalam. Two bands of gossans are exposed along the old workings.1 to 0. Sandur Schist Belt : Yeshwantnagar (15°32'30' : 76°30'00''). Only in one borehole a richer zone of 6. Dharwar schists (chlorite schists and hornblende schists) basic dykes and quartz veins Old workings with extensive coatings of malachite and azurite are seen over a strike length of 2 km in chlorite schist.8% Cu and 2. The average sulphur content is about 23. Garimanipenta (14°59'30'' : 79°33'10'' . Reserves of 0. Bellary district : 95 . The known evidences of mineralisation in Chitradurga Schist Belt are within the volcanic sequence and are mostly proximal to the volcanic sources for emplacement of the metal.57 N/9) Nellore District : The area exposes gneisses and schists of the Peninsular Gneissic Complex in the eastern part and Dharwar schists in the western part.56 E/11) Kurnool District: The area is made up of Peninsular Gneisses. Drilling data indicates that the zone of sulphide mineralisation is essentially made up of pyrrhotite and pyrite with subordinate chalcopyrite and sphalerite. In one borehole. only one intersected sporadic copper mineralisation. This zone is traceable over a strike length of about 300 m. massive pyrite zone of 9 m thickness was intersected.20% Zn was intersected.in strike length of about 5 km. The zones of copper mineralisation are narrow with copper contents of 0. 812 million tonnes with 1..07% Cu. mostly under soil cover. grey and white quartz.15% Ni.24% Cu. pegmatite and quartz veins. Sericitisation is developed in the vicinity of the copper mineralisation. The copper mineralisation is localised in a NESW trending shear zone. The orebody is reported to consist 4 sub-parallels to parallel zones ranging in length from 450 to 1100 m and in width from 5 to 40 m.blogspot. Deposits associated with sheared quartz veins and metabasic rocks traversing granitoids : Kallur (16°08'30': 77°12'25''). Blue and grey quartz carry sulphide mineralisation. biotite gneiss intruded by amphibolite.3% Cu. At a cut-off of 0. pyrrhotite and molybdenite. and 20 ppm to100 ppm Co. Raichur district: The area. A reserve of 2. Evidences for mineralisation are seen in the well cuttings only. The chemical analysis of the borehole cores from 32 shallow boreholes have given low copper values ranging from 10 ppm to 0. chalcocite and bornite associated with pyrite and pyrrhotite. Mailaram Belt. native copper occasionally seen as specks and flakes along joints and associated with specularite and haematite. Viz. whereas the white quartz is barren. Khammam District : The area comprises quartz-chlorite schist. Exploration by drilling indicates that there are three orebodies in the area. Chalcopyrite is the principal ore mineral and is associated with pyrite. 70 ppm to 0.Integrated surveys by GSI has indicated that the sulphide mineralisation is very poor. The oreshoots are narrow and range in width from less than a metre to a maximum of 12 m. Main Oreshoot (400 m). highly scattered and erratic in nature. within silicified metabasalts of Krishnanagar formation of Sandur schist belt. Central oreshoot (140 m) and Northern oreshoot (l60 m). 96 . Mailaram (17°43': 80°38') Deposit.The ore zones are lenticular with the maximum width in the central part. The average width is around 2 to 3 m. The deposit is now being mined on a small-scale by the Andhra Pradesh Mining Corporation Limited. 10 to 20 ppm Pb and 30 to 100 ppm Zn. The quartz-chlorite schists is traversed by numerous veins of black. reserves are estimated to be 0.in Copper mineralisation occurs in the form of disseminations and stringers of chalcopyrite. The area is largely covered by soil. The schists and gneisses (of the Sargur Supergroup) trend NE-SW and dip at 50 to 85° towards south-east. granite.85% Cu has been estimated by the DMG.visit: grvmalaikalam. diorites and pink porphyritic granite has been investigated by 30 boreholes by the Department of Mines and Geology. comprising granite. The Mailaram block extends over a strike length of 1100 m and has been explored by 20 boreholes drilled by GSI. Copper mineralisation in the area consists of disseminations of chalcopyrite and pyrite.47 million tonnes with 0. Majority of the values lie between 0. the Konkanhundi layered complex. four lodes have been delineated.6% Cu have been inferred. The mineralised zone extending over a strike length of 1.80 m of shaft sinking and 1879.blogspot.S18°E.91 million tonnes with 0. The work.in Machanur (16°15'50'': 72°42'30"). Raichur district : Specks of chalcopyrite associated with malachite and azurite with minor specularite and pyrite are noticed in the shear zone.80%).beneficiation etc. norite and anorthosite.97% Cu.95% Cu has been estimated. Subsequently. These boreholes have tested a strike length of 430 m. covering an area of about 50 km2 and consisting of a rhythmic. On the basis of drilling data. Mysore district: In this area of high grade granulite rocks.12 and 0. The deposit has been explored by 26 boreholes drilled by DMG. Although the width of these ore bodies and total reserves are fairly large (6. concluded in view of the low grade ore. The economic viability will depend on the cost effectiveness of the mining and beneficiation techniques. Sowanahalli (12°08': 76°48' . The Kallur. 250.33% Cu.15 to 0.14%. the average grade is again marginal (0. Sulphide mineralisation is noticed in the northwestern part of the complex in the form of gossans and malachite encrustations along fractures in a dolerite dyke trending N18°W . The gossan zone is traced for a strike length of 400 m intermittently.60 m of level developments in two levels were carried out over a strike length of 300 m in the central part of the block. Tinthini (16°23': 76°31') Gulbarga district : Copper mineralisation is seen in the sheared and brecciated hanging wall contact of the metagabbro dyke over a strike length of 5 km. stringers and disseminations of pyrrhotite.5 to 14 m contains on an average. 97 .visit: grvmalaikalam. pentlandite. Reserves of 1.25 km with width of 4. was therefore.The lodes range in width between 2 and 30 m with copper contents of upto 3. layered (and concentrically arranged) sequence of gabbro. Reserves of about 1. along with conspicuous non-layered norites occurs as an oval shaped body within the Peninsular Gneissic Complex.57 D/16). 0.23 million tonnes). The mine development indicated that there is no improvement in the grade at depth. 13 boreholes drilled by the DMG indicated mineralization consisting of veinlets. Old workings are also present. Machanur and Tinthini deposits are located close to eachother and can probably be worked as a cluster with common facilities for milling. the deepest intersection being at about 210 m. the deposit was taken up by exploratory mine development by the Hutti Gold Mines Company Limited.The area has been explored by 6 boreholes drilled by DMG. chalcopyrite and pyrite.84 million tonnes with about 0. blogspot.in intersected over narrow widths in 7 boreholes.32 million tonnes with 1. The mineralised quartzite exhibits sinistral drag folds and is involved in intense shearing.23% Cu and about 0.60 to 26.North Kanara district: The rock formations in this area consist of rnetasediments. quartz-sericite schist which are the host rock of the copper mineralisation and ultramafic rocks.48 J/9) area. Government of Karnataka. with copper values of 0. The rock types in the schist belt comprise hornblende schists.d. Kaiga (14°51': 74°26' .20 to 2. Hassan district: The Kalyadi copper deposit is located in a supracrustal Dharwarian schist band relict in the migmatite terrain of the Dharwar Craton.89% for the 6 levels. quartz-chlorite schist and to a minor extent to amphibole-biotite schist.14 to 0.20 to 3.Mothimakki (14°45: 74°34' . pentlandite and bismuthinite and rarely native gold are also recorded.34 m) is also adequate to permit larger scale operations.8 million tonnes and blocked out reserves at 1.03% with an overall average of 0.50 m widths and Ni values of 0.37% over 0.9 m.visit: grvmalaikalam. mine and the width of the orebody (average 14. Reserves are placed at 0.31 m (average 14. Copper mineralisation is confined to the sheared and folded quartzite.Drill indicated reserves are placed at 3..quartz diorite and gabbro which occur as intrusives. The reserves are adequate to support a 500 t. 34 boreholes drilled by GSI and Department of Mines and Geology.2 million tonnes. But the average grade of the ore is marginal. and economic viability will depend largely on the feasibility of major reductions in the cost of mining. milling and beneficiation. ultramafics and metavolcanics of Dharwar Supergroup surrounded by granitic gneisses and traversed by dolerite dykes. 98 .p. Deposits associated with schist belt enclaves in Peninsular Gneissic Complex : Kalyadi Copper Deposit (13°14': 76°09' 57 C/4). peridotite and gabbro which constitute the ultramafic complex in the area. The average copper content in the various levels range from 0. indicate that the orebody ranges in width from 5.59 to 1. slickens-siding and puckers folding.34 m).42% over widths of 0. quartzites. Sulphide mineralisation of the disseminated and occasionally massive type is found in the pyroxenite.10 to 0.48 J/3) .2% Ni.Exploration by drilling in the Kaiga area has delineated a zone of copper mineralisation over a strike length of 300 m.Marcasite. Pyrrhotite is the dominant sulphide with pyrite (cobalt bearing) and chalcopyrite in subordinate amounts. Aladahalli (13°08': 76°21'. The basal part of the Bababudan group comprises conglomerate (quartz pebble) and current bedded quartzite and quartzsericite schist which are the host rocks for sulphide mineralization.8% cut-off with 1.in Kalasapura (I3°17': 75°56': 48 O/15).1%. The gossan zones listed above have been tested by drilling – 20 boreholes in Aladahalli Main block. 0.03% Cu.5% cut off with 3.3 boreholes in Bhaktarahalli block. In the Aladahalli West block. 5 boreholes in Mangalapura block and 1 borehole in Ugranahalli block. The sixth borehole drilled to test the eastern zone intersected a 16 m wide sulphide zone out of which a width of 2.43% (average 0. Several discontinuous NW-SE trending gossan zones are seen near Aladahalli.16 million tonnes with an average grade of 0.In the Balehalli block the copper content seldom exceeds 0. Uranium mineralisation is also associated with the quartzite and conglomerate. 57 C/8).186 million tonnes with 0. Balehalli.13 to 0.5% cut-off.25%). 0.The ten boreholes drilled in the Dasapura block have Reserves of 0. the following reserves have been estimated : 1% Cut-off with 1.48% Cu. The 99 .27 m) with copper contents of 0. Nine boreholes drilled in the area by GSI have indicated zones ranging in width from 1.83% at 0.visit: grvmalaikalam. two zones of mineralisation are present but no significant sulphide zone was intersected. Sulphide mineralisation comprising pyrite. Mangalapura and Ugranahalli. 17 boreholes in Balehalli East and Main block.75% Cu.1 m yielded 0.24% Cu.25% has been estimated over a strike length of 240 m. Hassan district : This is a narrow NW-SE trending schist belt within the Peninsular Gneissic Complex. Chikmagalur district: The area forms the southeastern part of the Chikmagalur schist belt and consists of Precambrian metavolcano-sedimentary suite of rocks belonging to the Bababudan Group. 7 boreholes in Aladahalli West block.6 million tonnes with 1. The mineralisation is conspicuously restricted to the uppermost contact of the quartzite with amygdular amphibolite.34 million tonnes with a copper content of 0. 10 boreholes in Dasapura block. Dasapura. chalcopyrite and pyrrhotite occurs as disseminations in micaceous chlorite schist. Bhaktarahalli. It may be worth while to explore for mineralisation of the type associated with the conglomerates at Kalasapura. In Aladahalli Main block.blogspot. Reserves of 0.757 million tonnes with 1.10 to 8 m (average 3. d. pentlandite and cubanite) is indicated in gabbro and titaniferous magnetite bands over an area of 600 m x 200 m.3 to 1. Idagondanahalli (12°39': 76°19'). pyrrhotite.8 m respectively.in five boreholes drilled in the Mangalapura block also did not indicate any appreciable copper values. In the Belgumba area.38 million tones of titaniferous-vanadiferous magnetite with a copper content of 0. The basemetal mineralization (pyrite and chalcopyrite) is seen in the magnetite gabbro occurring in the basal part of the complex.p. In Nuggihalli the average copper in the individual borehole ranges from 0.visit: grvmalaikalam.Occurrences of basemetal mineralisation with ultramafics have also been recorded from Ranganahallibetta (13°03' : 76°26'40'').48% over widths of 1. On the basis of drill hole data. The copper values were mostly less than 0.1% in the third level borehole.04% over 8. Copper values in these rock types range from 0.8 m in two boreholes.2 million tonnes of vanadiferous titaniferous magnetite with 0.36% over 4.8 to 5. the drilling data indicate copper values of 0. Zinc values in the sulphide zones in Bhaktarahalli and Mangalapura East block were found to range upto 1.56% whereas the copper content in the other rock types is less than 0. 100 . Kadikengalbetta (13°20': 76°16').18%. Reserves of 6. reserves of 8. sulphide mineralisation (pyrite.36% has been estimated on the basis of the 1st and 2nd level boreholes.1%. Deposits / occurrences associated with ultramafic complexes: Sulphide mineralisation (pyrite with subordinate pyrrhotite and chalcopyrite) associated with titaniferous magnetite bands is seen near Nuggihalli (13°01': 76°28').2%. Masanikere (13°51': 75°59'). In the Tagadur area. Belagumba (13°14': 76°18') and Tagadur (13°26': 76°26'). Mineralisation Exploitation of the deposits in the Aladahalli area can be done on small scale of about 300 t.Occurrences similar to Aladahalli sulphide zone is also recorded from Ramanahalli (13°23':6°20'). the metasediments (quartz-chlorite-carbonate schist with quartzite bands) of the Chitradurga Group are intruded by a gabbro anorthosite complex.4% with occasional high values over narrow widths. subject to economic viability.3 to 0. Hassan district. Tavarekere (13°51'30' : 75°57'30''). Copper is concentrated in the magnetite gabbro and vanadiferous titaniferous bands.19 to 0. The overall copper content is estimated to be around 0.Magyathhalli (13°53'30': 75°57'00'') areas (48 O/13).blogspot. Shimoga district : In these areas. The copper content in the ferrogabbro ranges from 40 ppm to 0.15 m and 1.34% Cu has been estimated.5% and nickel from 0.17 to 0. pyroxenites and maficultramafic rocks.Hills-Palar Ghat section and the second type of mineralisation consisting of pyrite. Old workings for copper are seen on the northern slope of the ridge near Hadabanatta village. norite and anorthosite. there are a number of reported occurrences of copper and copper-nickel-sulphide mineralisation from a number of locations. These occurrences are mostly associated with calc-granulites. geochemical soil sampling. only one basemetal deposit. Mamandur Deposit (12°02':79°02' . stratabound pyrite and pyrrhotite associated with pyroxene granulite and magnetite quartzite along Talbetta-M. gabbro. The general trend of foliation is NNE-SSW to NE-SW with dips of 60 to 65° towards SE.M. the multimetal lode with lead-zinc-copper and silver values and a parallel lode on the foot wall side with disseminated copper mineralisation.visit: grvmalaikalam. A total of about 30 boreholes were drilled and 607. The Mamandur area is made up of migmatites and charnockites with bands of garnetiferous biotite sillimanite gneiss. two types of sulphide mineralisation are noticed syngenetic. geophysical surveys and drilling by the GSI and the Directorate of Geology & Mining. of mine development was carried out. magnetite quartzite and a suite of ultrabasic rocks comprising pyroxenite. The Mamandur area has been extensively explored by large scale geological mapping.in Base Metal Deposits/Occurrences in SGT: Kollegal (12°09': 76°07') area. Mysore district: In this area located in high grade granulite terrain. In addition.46 m.. copper.57 P/4) South Arcot District: This deposit lies in the Peninsular Archaean complex in the transition zone between charnockites on the west and migmatites on the east. Exploratory mining consisting development of an adit level and the first and second levels have been carried out by the BGML. Government of Tamil Nadu under a collaboration programme with UNDP.blogspot. pyrrhotite and chalcopyrite occurring in the fenitised gneiss and associated quartz veins related to alkali syenite-carbonatite emplacement near Tomyarpalya . Viz.M. Galena from the mineralised zone has given an isotope age of 2581 to 2600 Ma. pyroxene granulites. Quartz barytes vein with galena and molybdenite have been recorded from the Alangayam area. the multimetal copper-lead-zinc deposit at Mamandur is so far known. silver and cadmium and the other disseminated copper sulphides and is considered to be of the stratiform 101 .. The exploration work has shown the presence of two zones of mineralisation. lead.Hills Ghat section and M. In SGT of Tamil Nadu. The multimetal lode comprises zinc. Viz. Drilling data indicate that the multimetal orebody does not persist beyond a depth of 280 m. is estimated to contain 0.14 5.16 5. The range in metal contents in the orebody are as follows : Copper 0.0 % The second zone comprising essentially of chalcopyrite is located about 10 to 15 m.20 0. the southern part being generally poorly mineralised and containing mostly chalcopyrite. It has been traced over a strike length of about 460 m. 1.blogspot. This mineralised zone has been traced over a strike length of 760 m. Appreciable concentration of chalcopyrite of possible economic significance is found only over a strike length of about 180 m.40 _____ _____ _____ 102 Grade Ag (g/t) Cd% 39.19 _____ _____ _____ 0.15 m. Exploratory mine development shows continuity of the orebody: the adit level of the BGML exposing the ore zone continuously over a strike length of 182 m.13 . which extends over a strike length of 180 m with a width of about 7 m and a depth persistence of 34 m. the ore reserves available in the orebodies are estimated to be as follows : A: Multimetal Lode Proved Probable Reserves (million tonnes) 0.23 to 14.visit: grvmalaikalam.13 million tonnes of ore with a metal content of 0. the northern part of about 300 m is relatively better mineralized and the sphalerite rich ore body extends over a strike length of about 300 m with an average width of 3.15 m and persist to a depth of 280 m in the dip plan . to the foot wall (western) side of the multimetal lode.15% Pb and 0. The reserves in this ore body are estimated to be 0.42 1.45% Cu.92 0. 0. 0.53% Zn.in exhalative volcanogenic sedimentary type. The depth persistence of the lode is also limited to about 35 m.88 0. in some sections with an average of about 3.17 to 1. The chalcopyrite rich ore body.12% Pb and 37 g/t Ag. Drilling and exploratory mine development data indicate that the width of the multimetal orebody ranges upto about 9 m.62% Cu. The average width of the lode is about 8 m. below the surface.37 1.54 1. Of this.16 to 1.66 million tonnes with a metal content 5.13 5. On the basis of the drilling and exploratory development data. Part of the zinc values in the lode are in the form of the zinc spinel gahnite.46 Average % Cu % Pb % Zn 0.86 % Zinc 2.04 % Lead 0.69 Zn. by drilling. in B: Footwall Lode 0.69 37.. Satyamangalam area (11°15'.13 0.14% Pb.66 million tonnes of ore averaging 0.blogspot. 1. so far known from Tamil Nadu. 58 A/15 & E/3) Periyar and Coimbatore Districts : In the Satyamangalam Group of rocks lying between the Moyar-Bhavani-Attur lineament in the north and Noyil Cauvery lineament in the south and forming a part of the Cauvery suture zone (transform fault?) which extend right across the Tamil Nadu State in an east-west direction from its western border with Kerala to the boundary of the Cretaceous sedimentary basin on the east. sulphide mineralization with coppernickel-cobalt and marginal PGE and gold values also occurs in sheared ultramafic bodies occurring within hornblende gneiss.visit: grvmalaikalam. silicified zones occurring within the metagabbros or close to the metagabbro hornblende-biotite gneiss contact. particularly zinc are only partial.12 0. The silicified zones range in strike length from 100 200 m to about 6500 m. This also is a small deposit with 0.d.62 0.11°28':76°54'-77°15. Sulphide mineralisation occurs in sheared. Thus the Mamandur Cu-Pb-Zn-Ag deposit is the only one multimetal deposit. as part of the zinc is present as gahnite. it should be possible to operate a small scale mine of about 150-200 t.0 IBM carried out Ore beneficiation tests and showed that the recoveries of metal. These zones contain pyrite. on a deposit of this size. its economic viability will be adversely affected. 5. But because of the presence of part of the zinc values as gahnite and consequent low recoveries during beneficiation and its isolated location. In addition. During regional geochemical survey and mapping by GSI. numerous sulphides in well dumps with copper-nickel-cobalt etc.42% Cu. values and as many as 15 silicified zones with development of in situ limonite after sulphides have been delineated. pyrrhotite and chalcopyrite with some nickel and gold values. Normally.p. as seen in the Nadukavundanpudur and Ballepalayam and other areas. Regional geochemical surveys in an area of about 350km2 falling along the strike extensions of the Mamandur deposit has not brought out any significant mineralisation.40% Zn and about 40 g/t silver. The 103 . In these areas also values of greater than 1000 ppm nickel and copper have been reported in association with ultramafic rocks.blogspot.8. 2 g/t gold and 0.Outcrops are rare due to soil cover.65% Co.The possibility of locating Cu-Zn-Pb mineralisation in the alkaline-carbonatite province of northern Tamil Nadu also needs examination Arumanullur (8°19'15'': 77°24'35'' .2% Cu and less than 0. But potential areas for search for copper-nickel sulphide mineralisation associated with mafic-ultramafic complexes are large. A few grab samples have analysed upto 2. Data of a few boreholes indicate that the sulphide content ranges from sparse disseminations of less than 0.Minor chalcopyrite.12 and 16.5 m to about 8 m. Incidence of pentlandite. A similar geological setting prevails over large areas to the East of Cauvery river in Salem and Tiruchirapalli districts in Toposheet Nos. On the basis of geophysical surveys and a few boreholes. 4.1% Cu.ultramafic complexes. Analytical data of core samples yielded less than 0. 0. Several bands of banded magnetite quartzite and sillimanite bearing gneisses are also present in these areas indicating that there may be possibilities of locating copper-lead-zinc deposits of the Mamandur type.Though the results of exploration so far have not indicated appreciable nickel and copper values in the various silicified zones and sulphide shows in ultramafic fragments from well dumps the over all geological setting is considered favourable to warrant further search. No copper deposits of possible economic significance have so far been established in Tamil Nadu.Kanyakumari District: 104 .9% Ni.in width of these silicified zones ranges from 0.6. 58 I/2.3 g/t Pt.57 H/7) and adjacent areas.1% Ni. pyrrhotite and chalcopyrite have been recorded from Chalk hills and Red hills area and the nickel content is fairly high in the limonitised peridotite/dunite suggesting the possibility of locating copper-nickel sulphide mineralisation associated with mafic . Chalk Hills area (11°43': 78°10': 58 I/12) Salem District : Some of the major magnesite deposits of the country are located in this ultramafic complex.1% to as much as 50% total sulphides in some sections. 0. pyrrhotite and molybdenite occurrences were noticed in pyroxenite and amphibolite near Godepalaiyam and Maranur. it is inferred that these ultramafic bands are of limited size ranging in strike length upto 200-300 m and in width from 2-15 m. The well dumps at a few locations indicate appreciable pyrrhotite and pyrite with subordinate chalcopyrite. 3.10. Sulphide mineralisation associated with the ultramafic bands occurring within the hornblende biotite gneiss country rock is seen in well dumps at several locations in toposheets 58 A/15 and E/3.visit: grvmalaikalam. Thaniar area (12°25' . in a NNE-SSW direction in a shear zone in metanorite.5 g/t for 7 samples have been recorded from the sulphide zones.visit: grvmalaikalam. and the width of the sulphide bearing zones from less than a meter to about 50 m.about 20 to 25°). Trench sample data have indicated copper values of 0. North Arcot & Dharmapuri Dists.blogspot.Harur .5% to about 5% in some bands. The thickness of the mineralized sections with a relatively better concentration of chalcopyrite ranges upto 4 m.36 million tonnes copper ore with 0.79°05') North Arcot Dist. resources of 0. Alangayam .12% Cu.and strike length upto 3. Since zoning of iron.05%. Groove samples indicated only 0.4% Cu are estimated.94% (average 0. as the dips are moderate . The nickel values in the area are 0. However. The occurrence near Arumanullur is by far the best known and contains the maximum concentration of sulphides.: Massive concentration of pyrite -pyrrhotite occur as thick bands in association with the pyroxene granulite and BMQ bands of this SGT terrain.34%).pyrrhotite – chalcopyrite mineralisation within meta-norite band is also reported from Pattankadu (8°37': 77°34').in In this area. lead. zinc. The concentration of sulphides in the other meta-norite bands ranges from less than 0. gold values of 0.This strike length has been tested by 13 boreholes. the sulphide zone has been traced over a strike length of about 135 m.44%) and nickel values of 0.9 m.02 to 0.5 km have been mapped.12% and nickel less than 0. Tirunelveli district. Five parallel bands with thickness upto 7. copper. A similar occurrences of pyrite .Bhavani belt. (true width about 12 to 15 m. The drilling carried out by the DGM indicated that the orebody is highly lenticular and discontinuous.12 to 1..12°40': 78°57' .12 to 0. copper upto 0.10 g/t to 1..16 g/t with an average of about 0. Analytical data of samples with fresh sulphides have indicated that the copper and nickel contents are very low. Here.72% (average 0. The strike length of these bands range from about 50 m to over 500 m.1%. Josiar Alangulam (9°53': 77°58': 58 G/13) Madurai District: Lead-Copper-Zinc mineralisation in calc-sillicate rocks was traced over a discontinous strike length of 200 m in a 3 m wide zone in this area. sulphide mineralization has been recorded from a number of meta-norite bands occurring in the Arumanullur area and in the areas lying about 3 to 10 km to the north and north-east of Arumanullur. the possibility of locating Mamandur type of copper-lead-zinc deposit in this area is considered worth examining. with iron at the base and copper-lead-zinc at higher levels is common the world over. : 105 .On the basis of the drilling data. Bhundelkhand granite complex and the Mahakhosal and Vindhyan Groups of rocks.09%).04%.37% Ni (average 0. pyrrhotite and chalcopyrite) hosted in pyroxenite has been recorded.(i. It is the largest single copper deposit known in Peninsular India. reserves available in the deposit upto –8 m. Incidence of pyrite has also been recorded from a number of locations and in association with the quartz-barytes and molybdenite mineralisation.30% and upto 0. The area comprises charnockites with pyroxene granulite.9 km with an average width of about 65 m. Malanjkhand Granitoid Belt: Malanjkhand copper deposit: The Malanjkhand (22°02': 80°43' . Chip samples have analysed Cu content between 0.7 million tonnes 106 .1 m wide quartz vein in a faulted and fissured zone. the Malanjkhand copper deposit is by far the best known. MECL and the mine development by HCL.58 F/11) Madurai District: In this area.48% Cu (average 0.L. about 600m below the surface) at a cut-off 0.0005 and 0. the possibility of copper zinc mineralisation in the vicinity of quartz-baryte veins and other sulphide mineralisation will be worth evaluating.in A large number of quartz baryte veins with galena have been recorded from the Alangayam area and galena is a common association with molybdenite bearing zones ores which occur along shear zones in a number of areas in this alkaline carbonatite belt. Vettilaimalai (10°27: 77°41' . The ore zone extends over a strike length of about 1. Near Narayanapuram in Thiruvallur district. The pyroxenite body is about 50 m wide and extends for a strike length of 290 m. The copper mineralisation is localised in the quartz reefs.visit: grvmalaikalam. associated with the granites and also seen within the granites near its contact with the quartz reefs.e.45% copper are estimated to be as follows: Proved:145.2 to 9. R. anorthosite and quartzofelspathic gneiss. pyroxenite. basemetal deposits and occurrences have been recorded from Malanjkhand granitoid belt. Of these. carrying specks of pyrite. On the basis of the drilling carried out by GSI. Since copper-lead-zinc-baryte zoning is reported from a number of areas the world over.blogspot. Trench samples have indicated 0. Hindustan Copper Limited.54 B/12) copper deposit located in the Balaghat district is presently under exploitation by open cast mining by M/s. Base Metal Deposits/Occurrences in Central Indian Craton: In Madhya Pradesh. sulphide mineralisation (pyrite. chalcopyrite and pyrrhotite was emplaced along the contact of norite body with country rocks. a 380 m long 5.18 to 0. The copper concentrates are expected to yield 1. low grade copper ore beyond the main ore body is also likely to be excavated.32 gm/tonne from 0.in Probable:50. Toposheet No. But some of the mineralised quartz reefs have sizeable widths and strike lengths.29% (cut-off 0.044 million tonnes of lead ore with 1. Imalia (23°36': 80°16'). and Dhorli (21°52' : 80°46' – 64 C/13).38 million tonnes of ore have also been estimated from this zone. In addition. In addition.4 million tonnes of 1. brought out any significant copper deposit.visit: grvmalaikalam.82% Cu. Jabalpur district : In the Imalia area 0.19% Pb. The areas with a similar geological set-up surrounding Malanjkhand copper deposit have been investigated. reserves are of the order of 0.03 million tonnes with an average copper content of 0.18% copper is also likely to be produced during mining. Deposits / occurrences in Mahakhosal Group : A number of basemetals occurrences mostly localised in the zones of shearing and faulting have been recorded from different parts of this belt. 0. 70 g/t of silver and 0. They are : Bhaunra Pahar (22°04' : 80°48') – Taregaon (22°03' : 80°51' – 56 B/16) area. Exploration to search for Malanjkhand type of deposits adjacent to Malanjkhand has indicated only sparse mineralisation. but a number of occurrences for copper have been recorded.2% copper). Gidori (21°52' : 84°43' – 64 C/9).4 million tonnes Possible:40.12 million tonnes of 0.28% copper.24 g/t of gold. The quantity of such ore is estimated to be about 93.blogspot. 64 A/6.075 million tonnes of copper ore with 1. Considerable scope for further search in the Malanjkhand belt as also other belts exists. presence of bismuth and arsenic has also been established in the sulphide ores of Imalia block there by suggesting 107 . During open cast mining. Bodapahadi (22°03' : 80°53'' – 64 B/15). 6. Parewa Dongri (22°02'35'' : 80°45'30'' – 64 B/15).04% molybdenum. Pathratola (22°00' : 80°55' – 64 C/13). The work has not. Manegaon (21°58' : 80°48' – 64 C/13).58 tonnes of Ag metal at an average of 17. Nawalia (23°39' : 80°28') area. If lower grade ore are also taken into consideration.3 million tonnes Total : 236. Significant molybdenum values are associated with the ore. Bhula (23°37': 80°20'). About 3 million tonnes of oxidised ores with 0.12% Cu over a strike length of 240 m have been estimated. blogspot.50% Cu viz. and Antri (26°03' : 78°15') and Bhageh (26°31' : 78°26') .in polymetallic nature of mineralisation.. Cadmium and tungsten values increase 108 .Jamtoli (54 P/10. 13 & 14) area.5 m.5% Pb. The copper values in the borehole cores varied from 50 to 500 ppm . 55 K/5) Zinc deposit. Shivpuri district.24°31' : 81O52' .20% Zn (mostly traces to 0. Chhatarpur district. Sidhi district : Sulphide mineralization confined mostly to the silicified shear zones has been intersected below 200 m depth in the boreholes.2% Cu. District Betul.Baheria Shear Zone (24°20' . Besides copper.5% Zn).81°56' .P. cobalt and nickel occur as traces in the mineralised zone.Gijora (26°04' : 78°28') areas. pegmatite and epidiorite emplaced along N-S to N10°E .51% Cu x 6. lead. The remaining boreholes intersected zones averaging less than 0. and 1. SD/6 – 0. SD/1 . Few samples gave silver values of 1 to 50 ppm. The maximum metal contents in core samples were 2. quartz vein and epidiorite has been recorded from Chichola (21°04': 80°40'). silicified fault breccia. galena. Deeper drilling will be necessary to get a complete picture regarding the potentiality of the silver mineralization. Ag and W. The possible strike extension of the zone with +0. pyrite and pyrrhotite occur within the mineralised zone established over a strike length of 265 m. Dura district. Copper and fluorite mineralisation localised in silicified fault breccia. 63 H/15).E78°22'30'' in Toposheet No. Multai Tehesil. The grade varies from 2 to 16% Zn. BUNDELHKAND GRANITE GNEISS Quartz reefs and veins traversing granite bodies revealed sulphide mineralization.visit: grvmalaikalam. Zinc is the predominant metal with minor Cu. Durg district. M.5% Cu is about 600 m. Cd.50% Cu x 2. Lead-zinc and fluorite mineralisation occurs in quartz veins.0.50% Cu x 9. The drilling results have proved the depth wise (60 m) extension of the silver mineralisation with a gradual widening of the zone with depth. Bahera . Pb.S10°W shear zones in Chandidongri (21°05' : 80°38'). Only 2 boreholes intersected copper zones averaging 0.0 m and 0. There are indications of a thin zone of supergene enrichment. zinc. Massive sphalerite ore studded with chalcopyrite. Gwalior district . at Salaiya (24°40': 79°45') .5 m. Bhawratekra (N21°57'40'': E78°21' . and sporadic galena near Andar (25°42' : 78°06'). 2.344 1. Pular Parsori 0. Kolari Zone III 8.58 m 0.89% Cu __________________________________________________________________________ 109 . Ran Mangli 0. But since a part of the zinc values are in the form of gahnite. The Bhawratekra deposit (Reserves 0.visit: grvmalaikalam.4 ppm Ag.308 1.47% Cu __________________________________________________________________________ 5.83 m average width . The reserves estimated at 2% and 4% Zn cut off upto a depth of 180 m are as follows :.p.85 million tones of 6.0% Cut-off 3.38 1.77 2. Dubarpeth 1.35-3.5 ppm Ag.18% Cu 2.in with the increase of Zinc values and silver values increase with Pb values and attains maximum of 115 ppm.4% Cut-off .85 million tonnes of 6.At 4% Zn cut-off of 5.d. Thanewasna 4.0% Cut-off 4.829 0.909 1.76% Cu 1.48% Zn.1.10 m average width .58 million tones of 4.03-4.80% Cu 5.48% Zn) can perhaps be exploited on a small scale of about 150 – 200 t. 120 ppm Cd and 3.25% Cu 0.119 1.52% Zn.65 m 1. ore beneficiation aspects will have to be critically evaluated. before decisions regarding feasibility of mining the deposit can be taken.1.08 0.4% Cut-off .23 m 0.272 6.blogspot. Five copper deposits and one zinc deposit have so far been delineated in Maharashtra as summarised below : __________________________________________________________________________ Deposit Reserves Grade Million tones % Average thick -ness(m) __________________________________________________________________________ 1.19% Cu 3.0 6.7 0.52 __________________________________________________________________________ Total 5+6 6. 85 ppm Cd.845 2.79% Zn 51-6.24% Cu 1.73 _________________________________________________________________________ Total 2-4 (1. Thutanbori 0. and 3.At 2% Zn cut-off of 5.81% Cu 1.0% Cut-off) 1.0. 308 million tonnes with 1.78 in Nagpur district. Ranchi. Nagpur district.in The Kolari (Zone-Ill) zinc prospect is located at 2 km S57°W of Kolari Village (20°48' : 79°31'. 55 P/5) about 75 km from Nagpur on State Highway No. 56M/10). Maharashtra.blogspot. Thutanbori and Ran Mangli.21. Ran Mangli and Thutanbori deposits close to each other and to the Kolari Zone III zinc deposit. 55P/9) are located about 30 km to the east of Umrer. Maharashtra. in Umrer Tehsil. The Thanewasna (19°51': 79°44'.300 tpd. Kolari.5 km) and (iii) The Baharagora Sector (Strike length . Thutanbori (20°51' : 79°35'.Pular (20°51': 79°30'. 55P/9) and Parsori (20°50' : 79°33'. Till 1970. Pular . lead and zinc have been recorded from eight districts of Bihar and Jharkhand. Some of the deposits in Singhbhum are very large and are being mined since 1908.visit: grvmalaikalam. They are: (i) The Turamdih Sector (strike length .3. but the grade (0. Exploration to-date has established copper mineralisation of possible economic significance in 3 sectors over a cumulative strike length of about 30 km in the central and eastern part of the belt.47% Cu.The reserves and grade of ore in the Kolari Zone III deposit appear to be adequate enough to sustain economically viable operations on a scale of over 500 tonnes per day.At 110 . Maharashtra. the Tehsil town. viz.08 million tonnes are fairly large.78. Bhagalpur. Nagpur district. if a common infrastructure can be established for all the four deposits. a Tehsil headquarters of Nagpur district. Palamau. Almost half of them are copper occurrences located in the Singhbhum Copper Belt of Singhbhum district. 56-M/9).5 km) (ii) The Tamapahar-Rakha Mines-Roam Sideshwar-Chapri-Kehdadih-Surda-Mosabani-BadiaMainajharia Sector (strike length .89% Cu) is marginal.5 km) Over 150 occurrences of copper. The combined reserves at 6. The combined reserve in these deposits works out to 1. 55P/5) prospect lies at 58 km from Nagpur on State Highway No. 55-P/9) prospect is located at about 15 km on the fair weathered road from Pauni. Maharashtra. Shahabad and Gaya. the Mosaboni Group of mines were the only copper mines in the country.Parsori.Santhal Parganas.The feasibility of mining them will largely depend on economic considerations. Base Metals in Eastern Indian Craton Singhbhum copper belt extends over a strike length of 128 km in the Singhbhum district of Bihar. Chandrapur district) deposits also occur close together in adjacent parallel zones. Hazaribagh. Ran Mangli (20°48' : 79°27'. viz. They can perhaps be mined as a group of small deposits. Chandrapur district) and Dubarpeth (19°40': 79°30'. on a scale of 200 . Singhbhum.The Pular-Parsori. 90 1.53 1. indicated that the Rakha Mines block and adjacent areas constitute a highly potential prospect. The average content of these elements in the lodes of the area is as follows: 111 .54 2. southern and eastern parts of Ranchi district and in southern Bhagalpur district. In Singhbhum Copper Belt .66 200.10 1.79 30. The Rakha Mines block was worked by M/s Cape Copper Company between 1908 and 1923.54 1.400 m is continuously mineralized.30 0.28 1.55 105. are associated with the copper lodes. etc. Except 2 occurrences of lead with some copper in Palamau district which are associated with sedimentary rocks of Lower Vindhyans.t.59 85.) (% Cu) (in m. In the Tampahar-Rakha mines-Roam Sideshwar sector the lodes have been tested by drilling to depths of about 600 m and have been found to persist without signs of bottoming.15 35.) (% Cu) (in m.02 114.96 Besides copper.visit: grvmalaikalam. nickel. An evaluation of the Mine assay plans.52 0.The entire strike length of about 5.8 0. Copper-lead-zinc mineralisation appears to be confined to Hazaribagh and the adjacent Santhal Parganas districts.0 0.t.17 60. The copper lodes have been emplaced principally along shear fractures developed within the shear zone..16 2.t. The lead-zinc mineralisation is widely distributed in the western part of Singhbhum district.) (% Cu) 14. below the surface. ______________________________________________________________________ Proved Probable Cut-off Reserves Grade Reserves Grade Grade % Cu 1. Tamapahar-Rakha Mines-Roam Sideshwar Sector: (22°36'N to 22°38'50''N : 86°21'08''E to 86°24'E) This sector carry very significant copper mineralisation.t) (% Cu) (in m.24 1. and drilling data of M/s Cape Copper Company.blogspot..74 1. The estimates of insitu ore reserves for the three blocks are furnished.33 4.in present copper mines in the Mosaboni and Rakha-Roam Sideshwar areas are being operated by Hindusthan Copper Limited.49 2.27 0.95 15.99 10.5 1.Chalcopyrite and pyrite are the principal sulphides in the mineralised zone.38 1.5 Possible Reserves Total Grade Reserves Grade (in m. The Mosabani mines have been developed to a depth of about 1250 m. the remaining occurrences are found in Archaean rocks.99 79.94 40.100 .16 0. a number of other elements such as molybdenum.99 49.05 2.86 1. 74% Cu have been estimated.24 million tonnes with +1. vertical depth.in Nickel 0. These boreholes have tested the depth persistence of the lodes upto 300 m. Chapri-Sideshwar-Kendadih area : This area extends over a strike length of 5 km.80% Cobalt 0.73% Cu may be available for open cast mining.007% Sulphur 2. The reserves estimated in this area are as follows : 112 . The Sideshwar/Chapri zones have been investigated over a strike length of about 2.1 g/t Copper concentrates with over 24% copper with recoveries of +96% were obtained. In the Chapri area. The maximum reserves potential down to 600 m depth at a cut-off of 1% Cu can be of the order of 20 million tonnes per km. i. The Rakha mines and Roam-Sideshwar blocks were taken over by M/s.02% P 20 5 0. Probable reserves of 7.3 km by 66 boreholes (total meterage 20703 m) by MECL.blogspot. The potential reserves over the mineralised strike length of 3068 m down to a depth of 300 m is about 8.008% Arsenic 0.e. about 100 million tonnes over the 5 km stretch.Hindusthan Copper Limited in 1974.025% Bismuth 0.There are six copper lodes occurring in an en-echelon pattern.71 million tonnes of 0. The drilling carried out by the MECL indicates that there are several ore lenses ranging in strike length from 100 to 500 m localised mainly in quartz-chlorite schist.011% Molybdenum 0.10% Selenium 0. Sideshwar-Chapri-Kendadih-Surda sector: The ore reserve potential of this sector is very high and is yet to be fully assessed.25 million tonnes with 1. Kendadih mine area : Several rich lodes have been developed in the mine workings. the ore zones are fairly wide and reserves of 14.visit: grvmalaikalam.60% Cu.55% Silver 1 g/t Gold 0.0025% U308 0. The mineralisation is hosted in biotite-chlorite schist occurring in sheared soda granite.in Proved 2.27 1.13% Cu At 0.1 to 2.visit: grvmalaikalam.5% Cu 0. These boreholes have intersected several thin zones with 1 to 5% copper alternating with low grade zones.t. Probable reserves upto 100 m depth are estimated to be: Cut-off Reserves Grade 1. Pathargora. the probable reserve comes to 0. Surda and Badia Mines and Dhobani (old mine) of M/s.Dhobani (22°31' : 86°27') Mines area : In this sector.t. The Mosaboni. Probable 1. Khadandungri (22°26': 86°32') area : 113 .47 m.5% Cu cut-off. the mineralisation is distributed in a much wider zone of shearing (upto 5 km) than in the Rakha Mines sector. Drill indicated reserves of 5. with 3. with 2.t. Possible 1.blogspot.5% Cu cut-off 1.58% Cu.0% Cu 0. viz. At 1% cut-off. Surda (22°33' : 86°26') .2 km has been investigated by GSI. A probable reserve of 1.6 m) spaced 150-200 m apart drilled by GSI.41 m.25 m were met with in most of the boreholes.653.Badia (22°29' : 86°28') .t. A number of mineralised zones ranging in width from 0.24 m. with 2.32 m.Pathargora (22°32' : 86°27') – Mosaboni (22°31' : 86°23') .t. Mainajharia and ChirudihSomaidih are also present.798 m.91% Cu Chirudih-Samaidih area : 9 shallow boreholes were drilled by GSI. with 2.46 m.61 m. Tamajhuri.5 km.4% Cu There is therefore considerable scope for further exploration and increasing the rate of ore production from this 21.t.70% Cu 0.59 0. A strike length of about 3.47 m. Hindusthan Copper Limited are located in this sector.t. with 1. A few other mineralised areas.5 km stretch of Tamapahar-Rakha Mines-Roam Sideshwar Sector.t.39% Cu has been estimated at 0.01% Cu Surda-Mainajharia Sector : This sector extends in a NW-SE direction over a strike length of about 8. Probable reserves are estimated to be: At 1% Cu cut-off 0. Tamajhuri (22°32': 86°26') area: The area has been explored by 18 shallow series boreholes (total drilling 2. Copper mineralisation is closely associated with the metabasics and their derivatives and is co-folded with the host basic schists.86°11'43''). The area has been sub-divided into six blocks for purposes of exploration. The uranium mineralisation occurs on the hanging wall side of the copper lodes in the Turamdih deposit and in the Narwa Pahar (22°42' : 86016'). Molybdenum. vanadium and titanium are seen associated with mineralisation.Uranium and apatite deposits are also found in this sector. 3.3%. Drilling in the area has established mineralisation over a length of 630 m. Copper mineralisation of varying intensities is seen to persist over the entire strike length of 1320 m explored in detail. 5. The average thickness of the zone is about 1 to 3 m and the average copper content is 1.22 m). The mineralisation is confined to amphibolite.Rajdah Sector : A cluster of significant copper deposits with an aggregate reserves of about 30 million tonnes and lying close to each other have been identified in this sector.2. Mohuldih (22°44' : 86°09'). Kharkari River ..Bayanbil (22°44'00'' : 86°14'30''). Zones of richer concentration constituting the lodes occur as lensoid bodies predominantly within the chloritequartz schist.Nandup (22°44'30'' : 86°14'15'').Turamdih (22°43'2'' 22°43'53'' : 86°10'47'' .4.The total strike length of about 3500 m has been investigated by 45 boreholes (total depth 7823. The total length of mineralised zone is about 1 km.blogspot. Besides these a few other significant occurrences are also located in this sector viz.visit: grvmalaikalam. They are :1. Turamdih Sector: 114 . The drilling has established the mineralised zone upto a depth of 200 m. Garadih (22°43' : 86°14') and Keruadungri (22°44' : 86°11').in The rock formations in the area belong to the Chaibasa stage. Baharagora (22°16'15'': 86°43'00'') Sector : This sector lies in the Singhbhum district of Bihar near the trijunction of Bihar.Ramachandra Pahar (22°43' : 86°13'). Rajdah (22°41' : 86°17'). West Bengal and Orissa States. Hitku (22°42' : 86°15').Dadkidih (22°44' : 86°10'). Turamdih area : The deposit has been explored in detail by close spaced drilling and exploratory mine development.Of these the Turamdih deposit is the largest. only the Turamdih prospect has been investigated.270 2.18 1.87 1.74 Dhadkidih 3.52 ___________________________________________________________________________ (ii) Of these deposits. 2A & 2B) Million Grade Million Grade tonnes % Cu tonnes % Cu 1.in (i)A cluster of deposits viz.85 1.29 Ramachandrapahar 1.5% Cu 7.81 7.70 1.59 Nandup 4.42 ___________________________________________________________________________ Total 28. Zones of richer concentration constituting the lodes occur as lensoid bodies predominantly within the chloritequartz schist.09 1. Nandup.visit: grvmalaikalam.25 1.0% Cu 17.371 2. The deposit has been explored in detail by close spaced drilling and exploratory mine development.2% Cu 12.992 1.. Ramachandrapahar.15 4.850 1.Bayanbil and Dhadkidih occur close to each other extending over a strike length of about 5 km. The drilling has established the mineralised zone upto a depth of 200 m A summary of the probable in situ ore reserves for different cut-off grades estimated on the basis of drill hole data is as follows : ___________________________________________________________________ Cut-off grade Total Reserves Reserves in major lodes (Lodes 1A.59 ____________________________________________________________________ A bulk sample drawn by the MEC was beneficiated by the IBM.50 Bayanbil 1. Turamdih.59 10.434 1.00 1. Copper mineralisation of varying intensities is seen to persist over the entire strike length of 1320 m explored in detail.36 1. 115 .100 1.0% Cu cut-off are: ___________________________________________________________________________ Prospect Reserves in Grade (% Cu) million tonnes ___________________________________________________________________________ Turamdih 17.blogspot. The reserves in these 5 prospects at 1. 95 1.81 2.06 to 2. of which 1.08% U3O8 and 0. The grade of the individual occurrences ranges from 1 to 15%. blebs and locally as thin stringers. it will be feasible to mine a higher grade at a cut-off of 1.L.31 1. 0.12 0.18 million tonnes with 1.29% have been estimated upto a depth of 200 m.42% Cu.) have been estimated to be as follows: __________________________________________________________________________ Cut-off Reserves in correlatable Reserves in grade lodes (lodes 1 and 2) uncorrelatable lodes Million Grade Million Grade tonnes % Cu tonnes % Cu 1.77 million tonnes upto a depth of 145 m may be workable.52% Cu it should be feasible to open a group of mines with a total capacity of about 2000 .90 0.2% Cu 1.7 million tonnes with a copper content of 1.blogspot.5% Cu 0.11% Cu with a recovery of 90%. Ramachandrapahar : Drill indicated reserves in an area of 540 m x 480 m down to a depth of 130 m below the surface are estimated to be 1.36 1. Probable ore reserves down to a depth of about 140 m (10 m R.69 1.15% Cu which on flotation yielded a good concentrate analysing 25. Data of 6 boreholes (total drilling 610 m) indicated that copper mineralisation occurs as several detached en-echelon lenses over a strike length of 160 m.09 1.visit: grvmalaikalam. In case the average grade of 1.03% Ni at a cut-off of 1% Cu.03 to 0. The zone of intense shearing where ore is localised is about 3 m wide.98% have been identified. impregnated with apatite and magnetite. Five lodes with width ranging from 1 m to 5. Bayanbil:Copper mineralisation occurs in magnetite bearing quartz-chlorite schist as disseminations.in The average grade of the sample treated was 1.2 m and copper content from 1.60 2. Nandup Prospect : Inferred reserves of about 4 million tonnes with a copper content of 1. 116 .3000 tpd in this sector.52% is marginal.74 1.5% at 1% cut-off.0% Cu 1.5% Cu.2% or 1. In view of the sizeable total reserves in these prospects and the average grade of 1. Inferred reserves upto a depth of 100/120 m are placed at 3. Galudih: The host rocks in the area are silicified quartz-chlorite schists.98 1.64 Dhakidih: The host rock for the mineralisation is quartz-chlorite schist. Hazaribagh district. old workings and mine spoils.visit: grvmalaikalam. Old workings are found at several places between Baraganda and Parsabera (24°04': 86°03'). Small occurrences of copper have been reported at Phaga (24°46': 86°56'). Rajdah-Tamapahar Sector: No significant copper mineralisation has been recorded. Bihar: There are many occurrences of copper.49%.84°00'). Amjhore Pyrite Mine Area: (24°35' .21% Pb x 0.km. 117 .89 to 2. The mineralised zones intersected vary in thickness from 1 to 2.21 sq.5m to 22 x 12 m in Toolsitanr area and from 3 x 1 m to 30 x 8 m in Charkipahari area. Some copper and molybdenum values are associated with the uranium mineralization.41% Cu x 0.22% to 1.blogspot.50 m and 0. chalcocite and galena. This zone occurs about 6 to 10 m above the pyrite horizon and dips northward at low angles. Four boreholes were drilled. The lens dimensions vary from 1 x 0.There are several old workings in the area about 2 km SSE of Bhairukhi village (24°36'00'' : 86°36'15''). Baghmari mineralised pockets (maximum extent 150 m x 50 m) are associated with dolomite marble and tremolite-actinolite schist. but some uranium deposits are located near Bhatin and Jadugoda. lead and zinc in this district.77 m) and metal content from 0.24°45': 83°50' .in Sankhadih: The area around Sankhadih-Kharswan is predominantly covered by alluvium. Charkipahari-Toolsitanr area: Copper-lead mineralisation extends over a strike length of 4 km in this area and is indicated by the presence of malachite and azurite stains.Three of the 11 boreholes drilled to test this zone intersected two en-echelon copper lodes.17 m and in copper content from 0. The main zone bearing these minerals extend from Baraganda (24°04': 86°04') to Parasia (24°09': 85°47') over a length of 30 km.04 m. Mineralisation is restricted to lenses of tremolite-actinolite schist within the granite gneiss.km.55 to 1. Bhusi-Bhandaria-Duarsar (24°50'20'' to 24°51'40": 86°35'45'' to 86°39'45'') and Baghmari (24°47': 86°45') in Bhagalpur district.The incidence of strata-bound lead-zinc mineralisation in the form of a thin seam varying in thickness from 0.17% Pb + Zn (Average 0.44% Pb + Zn) has been established by drilling over an area of 5.11 to 1.Bhagro-Bajra-Jhibra area (24°48'45'' to 24°49'55'': 86°32'45'' to 86°37'15'').11 m. disseminations of Chalcopyrite.77 m (average 0. Shahbad District: The stratiform Amjhore pyrite deposit (thickness 0. sulphur content about 40%) occurs in the uppermost part of the Bijaigarh Shale horizon of the upper Vindhyans over an area of about 100 sq. The maximum values obtained were only 1. 49% Cu at 0.83°20') and Chormaria (20°18'. Pur-Banera-Rewara Copper-Lead-Zinc Deposit: This polymetallic sulphide deposit of Bhiwara area occurs in metasediments with mineralization of Cu-Pb-Zn-Fe sulphides. 118 .86°42').The ore occurs in garnet-graphite-sillimanite bearing biotite schist and gneiss.The southern extension of the Singhbhum Copper belt (of Bihar) for a strike length of about 15 km in the Kusumbari (22°04' . Base Metal Deposits/Occurrences in Western Indian Precambrian Shield: Deposits in BGC: Rampura-Agucha Zinc-Lead Deposit: This deposit is a major recent discovery in the basement rocks – the BGC.blogspot.The Sargipalli shear zone in the Gangpur basin of Sundargarh district extending discontinuously over a distance of 35 km. from Lokdega (22°02' -83°55') in the east to Amatpari (22°12' .8% cut-off). Kesarpur (22°06' . calc-silicate and amphibolite.46% Cu.81million tonnes with 1.Hindustan Zinc Limited on a scale of 500 t.83°17') over a length of 29 km in the Bolangir district.p.visit: grvmalaikalam. pyrite. a number of scattered occurrences of galena are reported from Bolangir. Surwas-Lakhols-Satdadia Copper Deposit: This mineralized zone of copper sulphide occurs in metasediments of Bhilwara area with magnetitequartzite. calc-granulite and amphibolite. Apart from the above mineralised belts.The Adash prospect in Sambalpur deposit is also a small.The Kesarpur deposit is of marginal grade and reserves are low (2. and 2. and arsenopyrite occurring in the core of a synform in the basement (BGC) rocks. copper and silver in dolomitic marble and mica schist. marginal one: Reserves 0. They are: 1. which are devoid of mineralization except for these deposits.d. The Sargipalli deposit is being mined by M/s.The stratiform and stratabound mineralization includes sphalerite and galena as major minerals with minor pyrrhotite. Exploration of the Sargipalli deposit has indicated that these areas mostly comprise iron sulphides.83°38') in the west hosting lead mineralisation with subordinate zinc.86°41') area of Mayurbhanj district hosting copper mineralization. Sambalpur and Mayurbhanj districts with one significant zone in between Ampali (20°25' .in Two main mineralised belts are known in Orissa.93 million tonnes with 1. Delhi Supergroup The Khetri and Kho-Dariba copper sulphide ore mineralization and the polymetallic sulphide ore mineralization along Ajari-Basantgarh-Ambaji –Deri are the two major sulphide deposits. arsenopyrite. galena and chalcopyrite with minor pyrrhotite occur as tabular and lensoid bodies in cordierite-anthophyllite-chlorite rocks and amphibolite. cubanite. The zinclead-copper deposits of Ambaji and Deri are massive stratiform types located in the southwestern part of the Delhi Fold Belt. 119 .cadmium.silver. Akwali and Satkui-Dhanota. and pyrrhotite with minor arsenopyrite.fluorite and sulphur with minor gold. sphalerite.It occurs as a broad conformable Lead-Zinc-Copper sulphide clusters to bedding in graphite mica schists and calc-silicates. magnetite. Ajmer district in the Sawar-Bajta metasedimentary belt of Sawar Group of Bhilwara Supergroup and the carbonatehosted sphalerite-galena mineralization of Sawar Group. lead. pyrite. indium and mercury. sphalerite. Other major Lead-Zinc-Copper mineral deposits in Aravalli Supergroup occur at Mochia.Other oocurrences include the pyrite-chalcopyrite mineralization near Bajta. Zawarmala and Borai. Aravalli Supergroup Rajpura-Dariba-Bethumni (Zinc-Lead-Copper) Belt: This 17 km long belt of polymetallic sulphide mineralization in Aravalli Supergroup consists of ores of zinc.blogspot. copper. pentlandite.Ore minerals are chalcopyrite.The ores are synchronous with the second phase of Aravalli deformation resulting in localizing the spahalerite. Kolihan. pyrrhotite lenses. The major ores are are sphalerite.in Copper sulphide occurrences in the metasediments of Bhilwara area are known from WariLunera. molybdenum. pyrite. pyrrhotite. Massive stratiform copper-zinc ore deposits occur along Ajari-Basantgarh-Rohera-Pipela section in southwest fold belt confined to chlorite-mica-quartz schists and amphibolite.phosperous. Angeni Copper Deposit. pyrite. upto 5 cms thick with minor covellite and magnetite parallel to pervasive schistosity in a zone of basement-cover interaction.visit: grvmalaikalam. chalcopyrite.Zoned copper-lead-zinc and iron-rich minerals characterize Dariba mineralization. galena. galena and pyrite mineralization.arsenic. Khetri Copper Belt This 100 kms long belt has dominant stratabound copper deposits confined to chlorite schist and amphibolite at Madhan-Kudhan.Pyrite. cubanite. cobaltite. This is characterized as a Proterozoic mélange zone (ductile shear zones). Udaipur district: The metabasic chlorite schist bands in the basal Aravalli hosts thin discontinuous lenses of chalcopyrite. 5 to 6. Main. The regional structure is an anticline plunging at low angles towards north. The Main orebody is developed on the northwestern flank of an anticlinal structure and consists of five overlapping lodes over a strike length of 400 to 600 m. The lead orebody is being exploited by the HZL at the rate of 240 tpd..5 m. Three ore bodies.Z. Concentration of the mineralisation is better along depressions between the anticlines. only the lead deposit at Bandalamottu in Cumbum formation of the Cuddapah Supergroup is being worked on a small scale by M/s.The deposit has been investigated by 92 surface boreholes and a large number of underground boreholes and mine development by Hindustan Zinc Limited (HZL).in The base metal deposits of Gujarat are mainly located in Amba Mata deposit in Banaskantha district where the main prospect is 2 km long and 600-800m wide with mineralisation of mainly lead and zinc with subordinate copper. Viz. At present. As a result of the drilling and mine development. Agnigundala belt: The Agnigundala belt is located in the north-east corner of the Cuddapah basin. Bandalamottu deposit (16°13'30'' : 79°34'45'' . (about 20°dip). The only working lead mine of H. This area comprises dolomite and dolomitic limestones interbedded with phyllites and quartzites of the Cumbum formation of the Nallamalai Group. The thickness of the orebodies ranges from 1 . Zones of lead-copper mineralisation occur mainly in the upper part of the dolomite.Viz. Galena is the dominant sulphide mineral with minor chalcopyrite and occasionally sphalerite and pyrite.11 m and the average thickness of the individual lodes from 1. The mineralisation is generally poor where the dolomites are associated with chert bands. The bulk of the basemetal mineralisation is localised in the Nellamalai sub-basin. the mineralized zone in the Bandalamottu hill has been established over a strike length of about 1200 m with a down dip extension of about 500 m. The other base metal deposits are located in KuiChitrasani belt falling in Gujarat-Rajasthan. Hindustan Zinc Limited.. Over 30 copper-lead and zinc occurrences are located in this belt in the calcareous quartzites and dolomites of the Cumbum formation.The Eastern orebody is located on the eastern flank of the anticlinal 120 .L.blogspot. Base Metal Deposits/Occurrences in Purana Basins: As many as 70 of the 84 deposits/occurrences recorded from Andhra Pradesh are located in the rocks of the Cuddapah Supergroup.56 P/12) of Guntur district is located in this belt.visit: grvmalaikalam. Eastern and Western have been identified. 5 .visit: grvmalaikalam.I of the main orebody in the lower part of the upper dolomite horizon.In addition there is a zone of copper mineralisation below lode No.261 _________ 1. III.08 0.10 0. & V) Grade . and comprises the No. 121 . II.6 1.459 _______ Copper Ore: Grade .899 Eastern Orebody (Lode .t. IV.I) 3.The reserves estimated by the GSI for the various orebodies are as follows: __________________________________________________________________________ Average Grade Reserve (thickness) Pb % (m.059 Western Orebody (Lode .650 Eastern Orebody 1. The lead deposits are being mined by HZL (about 240 tpd). I lode only.84 to 6.A Grade .180 Western Orebody (Dolomite zone) 3.60 3.58 1.71% Total : Cu 0.571 _______ 11.B Main Orebody 1.15 6.48 3.B 2.1.100 Main Orebody (Lode – 1.12 5.The Western orebody is located to the west of the main orebody.49 3.99 7.036 _________ The reserves estimated by the HZL (over a strike length of 700 m) are of the order of only 2. I.46 million tonnes with an average lead content of 4.in structure which extends over a strike length of about 320 m. This ore body extends over a strike length of about 900 m.A Grade .It extends over a strike length of 150 m and comprises only lode No.0 0.775 Cu 0.I) 5.5 .45 1.) __________________________________________m_________________________ Lead Orebody: Main Orebody (Lodes I.blogspot.36 4.29 to 8.3.18 0.98% (at 2% cut-off). 79°42' .60 - Central 0. 122 .t) ___________________________________________________________________________ NE Dhukonda 1.46 8.visit: grvmalaikalam.22 SW Dhukonda 0.t) Lead Ore Reserve Grade % Pb (m.07 7.16 1. Due to structural complications it has not been possible to clearly establish the exact nature of correlation of the orebodies.17 8. Drilling data indicate that the orebodies occur as parallel en-echelon.Copper mineralisation is dominant and confined to coarse–grained quartzite.blogspot.59 1.94 - Nallakonda (16°13' . The area has been explored by 79 boreholes. The deposit has been explored by 72 boreholes drilled by GSI and exploratory mine development at 4 levels by Hindustan Copper Limited (HCL). Lead mineralisation is subordinate and is localised in dolomites.06 2. The orebody appears to have a gentle pitch of about 10 to 15° towards north-east.The rocks are intensely folded. Copper mineralisation is localised in coarse grained calcareous quartzites. The better zones of mineralisation are seen along the nose of major anticlinal drag fold plunging towards north-east.Prakasam District: The area comprises chlorite phyllites and grey argillites with intercalations of quartzites and dolomite of the Cumbum formation. Guntur Dist : The geological setting in this area is similar to that of Nallakonda. lodes of limited depth persistance and that the orebodies are repeated due to folding.40 1.The orebodies are spread over an aggregate strike length of 2 km.The downdip extension of orebodies ranges from 90 m to 400 to 450 m.in Dhukonda (16°13'30": 79°43'30" . The drilling indicated reserves are as follows: Block Copper ore Reserve Grade % Cu (m. in the southern and southeastern slope of Dhukonda peak and adjoining areas.56 P/12) deposit .98 Total 9.04 2.39 0.00 Western Dhukonda 0.13 1. The GSI drilling indicated the presence of mineralisation over a strike length of 1300 m and a vertical interval of about 60 m.48 0.51 0.56 P/12) Deposit.91 0. 5 m. Guntur Dist : The area comprises phyllite.38% Pb + 0. The mineralised zone has a strike length of 600 m.69% lead are estimated. The dolomite host rock is folded into an anticline plunging gently towards east and is partly sheared.40% Cu over0. The beds trend NE-SW with southwesterly dips of 35 to 60°.5 m. At a cut off of 2. The lodes pinch and swell both along strike and dip. The average width of the mineralised zone is 2. Prakasam Dist.Fifteen boreholes have been drilled. and dolomitic breccia intercalated with thick phyllites of Cumbum formation.56 P/11) area. to 30 m.t.82% were estimated on the basis of the drilling data by GSI.in The orebody comprise a series of parallel en-echelon lodes with sinistral shifts.3 million tonnes with 2.: The area comprises quartzite. several breccia zones of 0. The Ittammakuvva block has been explored by 5 boreholes.3 and 0.. Guntur Dist. In the Gabbilagavi block. in the southern limb. Peddagavalakonda (16°16'30'' : 79°39'30'' .blogspot.8% the highest value being 1.96% Zinc has been estimated upto a depth of about 150 m. below the surface.50% copper only. The area comprises phyllites interbedded with dolomite and quartzite of the Cumbum formation. Exploration by 4 boreholes has not indicated the persistance of breccia zones beyond 70 m. Lead mineralisation is hosted in dolomitic quartzite breccia and quartzite.56 P/11) area. This downward revision of the reserve estimate is mainly attributed to the limited strike and depth persistance of the oreshoots as revealed from exploratory mine development. Lead values range between 0.35 million tonnes with 1. stringers.0% Pb + Zinc.visit: grvmalaikalam. Reserves of the order of 3. slaty phyllite and argillite with interbeds of dolomitic limestone and quartzite of the Cumbum formation.Old workings in mineralised dolomite are seen over a strike length of about 1000 m. The area has been explored by 18 boreholes. pockets and streaks of galena and sphalerite with stray specks of pyrite and chalcopyrite.14 million tonnes with copper content of 1. thick are seen on the surface over a width of 800 m. are of the order of 0. with 1. Viz.77 m. Vummidivaram (16°09'19'': 79°25'3'' .The mineralisation is predominantly/in dolomite in the form of veinlets. But the reserves estimated by HCL after exploratory mine development over a strike length of about 150 m. in the northern limb and 200 m.43 m.56 P/8) area. reserves of 0. Four of these boreholes intersected significant zones of lead 123 . Karempudi : 16°23'30" : 79°40'40'' . Reserves of 0. depth probably due to pinching/faulting of the mineralised zone. Gabbilagavi and Ittammakuvva. The beds strike NE-SW with dips of 40 to 60° towards southeast.The area is divided into two blocks. Balam Devlam (Pb) located east of Bandalamottu. Lead zinc ores are localised in dolomites enclosed within Cumbum slates. Kanchugavi (16°12': 79°24' . Anticipated reserves are of the order of 0. Three dolomite bands are interbedded in the 124 .Zangamarajupalle belt: This belt is located in the south-central part of the Cuddapah basin and stretches over 50 km (N-S).73 J/13) deposit. Dolomites are the host rocks.blogspot.04% Pb and 1. Dips are moderate and rolling. 10. 4. 2. Lead. Gajjalakonda (15°45' : 79°24').30 m x 2. Mella Vagu. located 3.56 P/11) Prakasam District: Disseminations of galena are reported to occur in breccia zones in quartzites of the Cumbum formation. 6. 13.6 km NW of Bandalamottu. Out of 8 boreholes drilled. Tadivaripalle (Cu-Pb). Old workings are seen over a strike length of 150 m.60 to 3. Papayapalem (16°22': 79°38' .02% Pb + 0. only 2 boreholes intersected mineralised zones: 0. Yerrakuppukonda (16°12': 79°42'). Ramasamudram (l6°01': 79°24').55% Zn. 5. 11.in mineralisation in the lower dolomitic horizon with lead values of upto 8.visit: grvmalaikalam. 9.56 P/12) area.56 P/12) Guntur District: In this area galena mineralisation is seen in brecciated dolomite of the Cumbum formation. Guntur District : In this area specks of chalcopyrite and galena are seen in sheared and silicified dolomites of the Cumbum formation. Other reported occurrences are: 1. Sakalavonikuvva (Pb-Cu). Other occurrences in the Agnigundala area: Veerappakonda (16°12': 79°42' . Cuddapah Dist: The area comprises variegated slates and phyllites interbedded with dolomites and quartzites of Cumbum formation. Basuvapuram (15°24': 78°38'): Lead. Sarikonda (Cu).45m x 3. Old workings are seen over 500 m.18 million tones with 4% Pb. Chityale (15°28': 77°47') Lead.99% over widths of 1.19 m. Currapusala (Cu). Zangamarajupalle (14°46': 78°53' . 7. 12. Ling-alakonda (Cu) located along the NE continuity of Dhukonda Block. Varikunta . Copper. These zones do not appear to have dip or strike continuity. 8. Koilkuntla (15°13': 78°19'). Two boreholes drilled in the area intersected highly limonitised zone with malachite and specks of chalcopyrite. At the surface a persistant leached zone is seen over a strike length of 400 m. 3. The sulphides occur as continuous to semi-continuous beds /lensoid bodies in cherty dolomite with finegrained (stratiform) layers of sulphides along bedding planes..t. grey dolomite and black pyritiferous carbonaceous slates of the Cumbum formation. The Zangamarajupalle area forms the western limb of a doubly plunging major anticline. These boreholes indicated the persistence of the mineralised zone both along strike and depth. light to dark grey rock with argillaceous. Zones of shearing and brecciation occur in dolomite. three better mineralised zone Viz. Kothapalle block and Chikativaripalle block. vertical depths were drilled by the MECL.Subsequently..42 m. On the basis of the borehole data.The mineralisation is mostly stratiform and confined to the transitional zone between dolomites and cherts and the overlying carbonaceous slates.t. Thin chert bands occur interbedded with the dolomite. arenaceous and carbonaceous intercalations.63% Zn 1.57 J/13) deposit.: The area comprises greyish green slate. The total strike length of the block is 3. 2 in the Kothapalle 125 . The mineralisation mostly occurs in the grey dolomite. The upper dolomite is 3-8 m thick with chert band at the top.3 km divided into Golapalle East block. four series of boreholes spaced at intervals of 50 to100 m along the strike to test the mineralised zones at 50 m. 2. 100 m.91% Pb At 2% Lead + Zinc cut-off 2. The lower dolomite (10 to 20 m) is impersistent and merges with the middle dolomite in the southern part. The middle dolomite (30 to70 m) carries the mineralisation and is a finegrained. The reserves estimated on the basis of MECL data are as follows: Reserves At 3% Lead + Zinc cut-off 1.The area has been explored by 22 boreholes at intervals of 200m. It is developed all along the strike length of 2 km. Grade 2.Sphalerite and galena with minor chalcopyrite occur in association with pyrite at the chert bearing brecciated contact of the dolomite with carbonaceous slates. The lodes I to V in the main dolomite are lead-rich whereas the lode-V in the cherty dolomite is zinc rich.visit: grvmalaikalam.. Central Section (400 m) Southern Section (600 m) and Northern Section (200 m) have been identified.74% Zn 1.34 m. Cuddappah Dist.in slates.blogspot. 33 boreholes have been drilled in the Golapalle block.150 m and 200 m.There are 5 lodes (I-V in the main dolomite and one in the upper dolomite.3% Pb Golapalle: (14°45'00'': 78°54'00'' . 03 2. The strike trend is NNW-SSE with dips of 10 to 35° to east or west.70 3 1.22 1. Karredukuppa (14°51'30" .50 3.94 3. Drilling of 6 boreholes indicated only sporadic specks of galena and sphalerite.85% Zn and 0.88 to 3. The reserves estimated in the Golapalle block are as follows: Cut-off Pb + Zn% Reserve m.Ganga project. some of the old workings are very extensive with large open stopes.visit: grvmalaikalam.50 4.36 1. 0. thickness.78°49'30" .91 4 0. Six boreholes drilled in the area indicated that the mineralization is impersistant and lensoid.87 2. Cuddappah Districts : This area is located along the northerly strike extension of the Zangamarajupalle belt and comprises mainly Cumbum slates interbedded with dolomites and dolomitic quartzites. In the Gopalpalle block.86 __________________________________________________________________ The entire deposit falls in the submersion zone of the proposed dam site of Telugu .34 to 3. Chinnelupatti area. Two mineralized zones have been identified.t.33 km. The mineralisation appears to be of the pitches and flats type presumably pitching at 10° to 20° towards north. The old workings indicate a series of lenticular ore zones of 100 to 200 m strike length and 5-20 m. continuous mineralisation has been established over a strike length of 1.5 126 .20 to 4 m.59% Pb.46 2.89 1. Old workings in the area appear to be along a shear plane in dolomite as also along axes of minor folds in the dolomite.88 2. Cuddappah District: This area forms the northwesterly extension of the Zangamarajupalle-Kareduppan belt.55 4.25 to 0. An upper zone associated with cherty dolomite with mostly sphalerite and minor galena and a lower zone of chalcopyrite with minor galena. Varikunta (15°11: 78°46' .57 J/13) Cuddappah District: This area is located about 21 km south of Varikunta and has a similar geological setting. Random samples of oxidised zones analysed 0.30 2.57 I/16) area.72%) over widths of 1.23 5. Grade Pb% + Zn% Width (m) Total Pb + Zn% 5 0.76 3. The mineralisation is weak in the other two blocks. The metal content in the mineralised zones was found to be less than 2% Pb+Zn (0.in block and 5 in the Chikativaripalle block.63% Cu.37 2 1.61 1.blogspot.83 1. Galenasphalerite-chalcopyrite mineralisation within dolomites is noticed over a strike length of about 2.23 to 0. Gani-kalava belt . The country rock is green grey shale which carries dolomite lenses and quartz barytes veins with galena. Kurnool District: The mineralisation in the Gani block consists of an eastern sector of strike length 1100 m and a western sector of strike length 950 m with a gap of about 350 m.25 m. These are intruded by dykes of kimberlitic 127 .43 million tonnes with1. Chelima (15°30': 78°40' . reserves of 0. But the strike persistence of these values is very limited.7% Cu over 1. There is a marked angular unconformity between the lower Cuddappahs and the Tadapatri shales.The Gani-kalava copper belt comprises Vempalle limestone and Pulivendla quartzites of the lower Cuddapah Supergroup have overlain byTadapatri shales of the Kurnool Groups. Geochemical surveys have indicated several linear anomalous zones for zinc and occasional spot values for Pb and Cu.The Cuddappahs and Kurnools in the area are intruded by sills and sheets of metagabbro and metadolerite. stringers and pockets associated with breccia and quartz vein in traps or at the contact of the trap and shales. Copper ore occurs in quartz reefs (nearly vertical) cutting through the Tadapatri shales and traps of the Kurnool formation.57 I/6) block. Drilling in the eastern sector over a strike length of 500 m has indicated the probability of a significant and persistent zone of copper ore over a strike length of at least 300 m.blogspot. in between.57 I/11) Kurnool District: The area is made up of Byrankonda quartzite and cherty quartzites with dolomite. green shales. On the basis of borehole data. slaty and phyllitic shales of the Cumbum formation. Gani (I5°40'70'': 78°19'57'' . Ambavaram : Preliminary geochemical surveys indicate an anomalous zone of Cu-Zn over an area of 200 m x 4000 m. It is in the form of disseminations. Some borehole intersections have shown values of 1.Kurnool District: This belt extends over 16 km in the northwestern part of the Cuddapah basin. The mineralisation in the western sector is highly lenticular though old workings are extensive.37% Cu are inferred to be available over a strike length of about 550 m and a depth of 100 m. thicknesses. Mineralisation is confined to WNW-ESE trending shear faults occurring in the Tadapatri shales.Copper occurrences have also been recorded from Somayazulapalle (15°35' : 78°11') Kommamarri (15°12' : 77°53') and Gummankonda (l5°38'30' : 78°18'00'') in the Gani-Kalava belt.31 to 2.in km.visit: grvmalaikalam. 73% Pb over a width of about 5 m. The mineralised zone contains barytes. Three groove samples from trenches indicated values of 2.97 m. Basavapuram (15°24': 78°43'): Lead mineralisation associated with barytes is noticed in quartz veins traversing slaty rocks Pulivendla belt : Cuddappah District : Copper mineralisation associated with barytes occurring along shear zones in the Tadpatri formation have been recorded from Venkatapuram (14°24': 78°13').32% Zn. Eleven boreholes have been drilled. of which 3 intersected mineralised zones with upto 3.. over widths of 0. Vemula (14°22': 78°14') and Midipenta (14°19': 78°19').10% Pb+Zn over 0. thick zone with 5.96% Pb. Pacherla (I5°23': 78°42' .30% Cu was intersected. The zones of high values coincide with the known shear fractures in the area. thickness. slates. limestone. The chalcopyrite 128 . quartzite.36 to 8. Six boreholes drilled in the Venkatapuram area did not indicate any significant zones of mineralisation. Drilling of 12 boreholes indicated only weak mi neralisation with 0. Mallapuram (15°30'35'' : 79°10'30'' . The mineralisation is more conspicuous in the nose of the fold where the mineralised dolomite has a thickness of 10 m. dolomite and chert trending NNE-SSW to SW-SW with variable dips of 10 . chalcopyrite. and 6.57 I/12) Kurnool District: Copper-lead-zinc mineralisation in this area is hosted in dolomites o the Cumbum formation. Ahobilam (15°08': 78°40'30'' . The Venkatapuram block is situated on the western limb of an anticline. But drilling of 5 boreholes did not intersect any mineralisation of significance.in carbonatite.15 to 6. pyrite and galena.Two samples indicated 3. dolomite and ferruginous phyllite of the Pakhal Supergroup.30 to 4 m.57 I/11) Kurnool District: Galena and sphalerite and occasionally chalcopyrite and pyrite re seen in dolomite intermittently over a strike length of about 2 km. Khammam district: The area comprises phyllite.14 to 2. In a fourth borehole a 0.visit: grvmalaikalam.57 M/2) (Marakapur belt) Prakasam Disrict: The area comprises rocks of the Cumbum formation. phyllites with quartzite.15% Pb. The strike length of the mineralised zone is about 600 m Venkatapuram (17°46': 80°47') area.blogspot. Viz. Surface indications of mineralisation are seen over an aggregate strike length of 1 km.85 m.80° towards SE. Geochemical surveys in the Vemula area indicated an anomaly zone with lead contents of 300 to 1000 ppm. Mineralisation is found mostly in the zone of brecciation and dolomites. Three boreholes were drilled of which only one intersected 0. Yellambailu (17°41': 80°40') area. Ragaboyingudem (17°31': 80°22') Khammam District : The area comprises dolomite and phyllite with sheared quartz veins. Copper mineralisation is seen in quartz-chlorite schists traversed by grey quartz veins and the Pakhal quartzite and dolomitic limestone. 129 . The zone corresponding to the old workings analysed 1. Baryte is often associated with cherty quartzites.88% Zn and 0.27 to 1. tremolite. one corresponding to the line of old workings and the other in the underlying quartz-chlorite schists. The strike trend is NE-SW with steep dip towards north-west. Drilling of 15 shallow boreholes indicated that the mineralization occurs as lensoid bodies with limited strike and depth persistance.2% Cu.in mineralisation occurs as disseminations and stringers in quartzite and dolomite. dolomitic limestone.38% Cu over 2.2% Zn and 0.visit: grvmalaikalam. 0. Khammam District : This area is located 8 km south-east of Mailaram. Disseminations of chalcopyrite.68 m.08 m. 0. and quartz veins of the Pakhal Supergroup.68% Pb.5 to 5. 3) 2.61% Cu over 2. Excavations are seen over a strike length of 370 m. close to the Archaean and Pakhal contact. 2. Old workings are seen over a length of 120 m. Drilling of 8 boreholes has indicated two en-echelon zones of copper mineralisation with a cumulative strike length of about 150 m. phyllite.40 m. but within the Pakhal quartzites and limestones.97% Pb.65% Pb. 2) 0. They are : 1) 2.35% Zn and 0. marble. Khammam District : This area comprises cherty dolomites interbedded with phyllite and cherts and quartzites of the Pakhal Supergroup.blogspot. Venkatapalem: (17°16' : 80°13'). Only three boreholes indicated significant values.83% Cu over a width of 0. pyrite and galena are associated with dolomites.58% Cu over widths of 1.24 m.13% Cu. and comprises quartz-chlorite schists and biotite gneisses (Sargur Group) intruded by pegmatite and quartz veins and quartzite. Three boreholes drilled in the area indicated two zones of mineralisation. The average grade of the mineralised zone ranges from 1. There are a number of reported base metal occurrences in the State. One borehole intersected oxidised zone with 1.10% Cu over 1.10% Sn. The other explored occurrences are Dudhi (copper-lead-zinc) in Mirjapur district. KhanayunGalpakot-Kimkhet area (copper-lead-zinc) in Nainital-Pithoragarh districts and Tons Valley in Dehradun district. The total reserves of 3. Traces of copper on talcose laminae in limestone has been recorded at Khajjidoni (16°10' : 75°31' ) and north of Gaddankere (16°11' : 75°37'). was opened up by two adits by the MECL at 1015 m RL.visit: grvmalaikalam.55 m. Six boreholes were drilled. at two levels (1015 m RL and 985 m RL). The surface indications of mineralisations are seen in the form of a small outcrop unaltered. the Gorubathan lead-zinc deposit. in West Bengal.depth. in the Vindhyans and in the shear zones crossing the Bundelkhand granites. which had been explored by the GSI by drilling at 50 m strike interval. silicified epidoteactinolite biotite-quartz rock. hard. show specks of malachite and occasionally chalcopyrite.95% Zn in the area.blogspot.68% As. Askot (Copper-Lead-Zinc) Deposit (29°46': 30°20').062% Sb.83% TMC) along with 1. 2. A deeper borehole was negative. The southern ore body. width at 80 m. covering some 150 m.70 million tonnes with 130 .64% Pb and 3. base metal mineralisation is located in the large hilly tracts covered by the Garhwal Group of rocks. The exploratory mining carried out exposed the ore at 985 m level with 1.77% Zn (10.. the most important one being the Askot deposit which is described below. Pithoragarh district The sulphide mineralisation is confined to the northern limb of the Askot syncline near its southeastern closure. 0.0.77 million tonnes of ore averaging 2. In Uttar Pradesh. Base Metal Occurrences in Himalaya At the foothills of Himalaya.in Sarakal : (17°43' : 80°42'. Although these two occurrences are of sporadic nature. Incidence of copper mineralisation has been recorded from two locations in the Kaladgi basin of Bijapur district. (the most important one).39% Pb.32% Cu. 4. 4.65 C/10) In this area some old workings in felspathic quartzites and ferruginous quartzites (of Pakhal Group) are seen.68% Cu. only one basemetal deposit has so far been identified viz. The GSI has estimated reserves of about 0. the possibility of finding economically viable deposits for copper in the Kaladgi basin cannot be ruled out OTHER DEPOSITS . Two other shear zones viz.33%Cu with appreciable amount of lead and zinc has been tentatively estimated in the Ranga Valley (PotinYazali area).97% Cu and 1. The Sikkim-Darjeeling area is dotted with as many as 40 base metal occurrences confined essentially to the Daling/Darjeeling Group of rocks with biotitic granites occurring as tongue like bodies. (27°23' : 88°35'). host rock (dolomite). Peshok (Copper) (27°04' : 88°24'). but the average width of the orebodies (3.to Meso-Proterozoic age.27 to 4.blogspot.. But the reserves are distributed over a number of orebodies in several blocks.30 m) is a favourable factor. Zn with Ni. But the results of exploration to date have not indicated any mineralisation of possible economic significance in these shear zones. In the Lesser Himalayan sequence of West Kameng District of Arunachal Pradesh. Co. Proterozoic grey dolomite of Mukatung Formation of of Shergoan Group hosts lead-zinc mineralization in the form of galena and sphalerite. The IBM estimated following reserves for the Dikchu ore body. Recoveries of about 90% of the magnetite are reported. North Sikkim district. Dikchu (Copper-Zinc). Cu. are known from the state.5% and 2.90 lakh tonnes) Peshok (Copper) grades between 0. the deposit is similar to 131 . Drilling encountered poor mineralisation in Bhotang.. Palaeo to Meso-Proterozoic Polymetallic mineralization : The Bomdila Group of Lesser Himalayan sequence in Ranga Valley of Lower Subansiri District of Arunachal Pradesh hosts polymetallic (Fe.91% Cu and 1.87% Zn in this deposit may be adequate for opening a small mine of 300 to 500 tpd. and Pedong (Copper) (27°09' : 88°37').53% Zn Probable reserves:1.visit: grvmalaikalam.77% Pb + 3. These orebodies have only limited strike persistences of upto 240 m.in 3.In Pedong the richer zones have a grade of about 2. Rangpo. However. This is not a very favourable factor. The mineralization is confined to the magnetite bearing schistose units of the Potin Formation. Sn and W) mineralization of Palaeo. the fact that magnetite is the principal gangue mineral in the orebodies can favourably influence the economics of mining.23 lakh tonnes with 2.59% Zn Total: 2. Purulia-Bankura and Chirugora-Kutni-Beldih.85 lakh tonnes with 2. East Sikkim district . highly erratic in depth persistent. Two copper-rich zones with a possible reserve of 1. Pb.62 lakh tonnes with 3% Cu and 1.5% Cu (VE).55mt with an average grade of 0. metamorphic grade (lower amphibolite) and character of mineralization (strata bound) is concerned. The important copper-lead-zinc prospects are: Bhotang (Copper-Lead-Zinc) (27°10'30'': 88°32'00''). Proved reserves: 1. but so far as age (Proterozoic). The deposit is patchy.5% Cu (VE).56% Zn (2. The mineralized belt extends for a distance of about 9 Km on which four explorations blocks are located. mainly pyrite. tuffs. This deposit occurs in the Pullampet Shale of the Cuddapah Supergroup. vug fillings. BARYTE The largest baryte deposit in the world with a reserve of 74 Mt is located in Mangampeta in Cuddapah District. Gossanous bands have assayed 0. galena. Belgaum district.in that of Rajpura-Dariba Group of Rajasthan.80% copper. Strata bound sulphide occurs in the carbonate rich formations of the volcano – sedimentary sequence of the Garhwal Group in U. carbonaceous and/or calcareous slates and tuffs. slag heaps and gossans scattered throughout the area are indicative of base metal mineralisation. haematite and maghemite are other associated minerals.K. where more than 300 mt of lead and zinc been discovered by G. disseminations. 132 . Himalaya. Fractures and shears. Dharwar district: The metasedimentary-volcanic suite consist of andesite flows. these occurrences contain a number of old workings 2)Kwanu lead-zinc-copper belt in Uttrakhand in Deoban group of rocks: The Kwanu lead-zinc-copper belt extends over a strike length of about 1km from Chamri in the southeast to Anyar in the northwest.64 to 12. Anyar is located in the adjoining state of Himachal Pradesh.I.visit: grvmalaikalam. Deccan Traps: Native copper as thin films along joints. Though a good concentration for and economic deposit has not yet been demarcated. vesicular in fillings and disseminated grains have been reported from the Deccan basalts near Handigund (16°25': 75°05'). Magnetite. The principal host rocks for mineralisation are dolomite. The base metal mineralisation in this area is associated with Sauli Formation of Deoban Group. Rain Agar. veins and patches of metallic sulphides.blogspot. Further exploration is required to assess the nature and intensity of mineralisation.S. 1)Pb-Cu mineralisation in the epiplatform carbonate sequence around Bora Agar. Traces of mercurous sphalerite and argentite are also present. parallel to the axial planes of tight folds are the main locales of mineralisation. whereas. Mineralisation occurs mainly in the form of stringers. Old workings. Shisakhani and Dhanpur in Uttarakhand Himalaya and Sirban Limestone around Sersandu in Jammu Himalaya. carbonaceous shales and ferruginous cherts. Late Palaeozoic metallogenic epoch mainly associated with volcanic rocks. sphalerite and chalcopyrite. Nagavand (14°20': 75°35'). shale. Amtiyargad and Chamri prospects of this belt are in Uttarakhand. Uttarakhand.2900 ma. Batwari and Kheel in Sirmaur districts of Himachal Pradesh and in Kinnaur district. In the Granulite Terrain of Tamil Nadu. In Askot copper-lead-zinc deposit. Gairi (Dewas District).000 tonnes are located in Kaami. Andhiri Kho. Bari (Sidhi district) and around Bhoiron in Tikamgarh district. dated to be ca. Baryte veins occur south of Phutana and NNW of Thanewasna. Mettuppalaiyam. Coimbatore District.baryte occurs in the septarian nodules in the concretionary zones overlying the Gunderdehi Shale near Dotapur in Raipur district. meta-pyroxenite / chromiferous metapyroxenite. chromitite.S. chromium and copper mineralisation. Barytesoccur as very thin vein along foliation planes in Musnota in Mahendergarh district and from Haripur in Ambala district of Haryana. meta gabbro ±garnet. Among these. Tenmudiyanur. Manehra (Jabalpur district). Torappadi. the major Sittampundi and Mettuppalaiyam complexes represent layered or differentiated sequences of dunite. In this state minor occurrences of baryte are noticed near Kopela and Jingaanur areas of Gadchiroli District and north of Ran Mangli in Nagpur district. The world's largest deposits of PGE are located in the Bushveld Layered Complex in South Africa and in the Stillwater complex in U. amphibolite.A. Baryte deposits of the order of 15. The mineral is associated with quartz veins near Alangayam. Sunehra. 0000 tonnes. the total reserves of barytes have been inferred to be about 20. nickel. gabbroic anorthosite and anorthosite. PLATINUM GROUP OF ELEMENTS (PGE) AND CHROMITE The ultramafic – mafic suite of rocks are considered to be the potential host for PGE. Mahadwari and Dewada areas in Chandrapur District of Maharashtra. Vellore District. 1425 tonnes of barytes are located in Aarsomang. In central India. 133 . several ultramafic-mafic -anorthosite complexes occur in Sittampundi. Kadavur and Oddanchatram areas. Dhar area (Dhar district). Manmalai. Pithoragarh district. These complexes.visit: grvmalaikalam.blogspot. Tatyana. The PGE mineralisation is generally concentrated in the basemetal sulphides and in the chromites. garnet-pyroxene granulite.in Baryte occurring as lenses in pegmatites occurs near Kurichchi. SW of Kerua Village near Harsi Reservoir (Shivpuri district). are emplaced within the amphibolite facies gneisses and the associated supracstals of Archaean age within the E-W trending Cauvery Shear Zone. 134 . Recent exploration (2007-2008) by GSI indicated the presence of PGE mineralisation in the form of Sperrylite (PtAsS).7 ppm over 0. Close-spaced sampling carried out subsequently has resulted in delineating two zones of PGE mineralisation in the Karungalpatti block – one in the chromitite band No.56 ppm of Pt + Pd over 3 m width and the other in the chromiferous meta-pyroxenite band no.I.5 m is found within the meta-pyroxenite band showing malachite-azurite encrustations. two zones of chromitite / chromiferous meta-pyroxenite have been delineated. preliminary sampling of the chromite-bearing metapyroxenite band has indicated 0. Braggite (PtS) and stibiopalladinite (PtAsS) reported alongwith pentlandite (NiS) and chrome-spinel within the chromitites in Chettiyampalayam Block of Sittampundi Anorthoste Complex. a significant zone of PGE mineralisation has been delineated for a cumulative strike length of 1. The PGE mineralisation with an average grade of 1.visit: grvmalaikalam. The depth persistence of these PGE mineralised zones is being tested by scout drilling.S.4 km with total PGE values ranging from 1 ppm to a maximum of 18 ppm in the chromitite chromiferous meta-pyroxenite bands.929 ppm of total PGE. In Tasampalaiyam block.5 m.5 m width. in the meta-pyroxenite of Solavanur block in Mettuppalaiyam Ultramafic Complex. In Mallanayakkanpalaiyam area. a significant zone of PGE mineralisation (1-4 ppm of total PGE) extending for a strike length of about 1.70 ppm. located at the western part of the Sitampundi Complex.45 ppm of Pt + Pd over 1.S. the western zone shows significant PGE mineralisation with Pt + Pd values ranging from 0. Chip samples collected from these bands have shown Pt + Pd values ranging from 0.25 to 1 m width.43 ppm of Pt + Pd. Similarly.G.III with an average grade of 1. Among these.in PGE mineralisation in Sittampundi Anorthosite Complex was first identified by GSI in the year 1984 when one of the seven chromitite samples analysed in U.7 ppm to as high as 6.blogspot. The average grade of PGE mineralisation in this zone works out to be 1.1 km has been delineated by G.8 ppm of Pt + Pd over a width of 2.S.The depth persistence of these PGE mineralised zones is being tested by scout drilling. Based on detailed mapping and close-spaced sampling in the adjoining Chettiyampalaiyam block. two linear bands of chromitite and chromiferous meta-pyroxenite have been delineated for a cumulative strike length of about 500 m with a maximum width of 3. with sporadic high values upto 16. In Karappadi block. has given 0.97 ppm of Pt + Pd.IV with 2.8 ppm of Pt + Pd over 1.47 ppm to 1.60 m width. 8 km between Sittampundi in the west and Karungalpatti in the east. are made up of chromite (50-60%). Chromite occurs as bands. Only minor chromite mineralisation is reported from Central India. Mallanayakkanpalaiyam and Solavanur areas in Erode district. Chromite generally are of podiform nature associated with ultrabasic intrsuives in the gneissic terrain. 135 . Nickel values upto 0.30%.Dhenkanal districts) .72 to 28. Vellore District.14% to 30.50 to 19.221 million tonnes upto a depth of 6 m. Peridote / dunite from Chalk Hills. Salem District has yielded upto 0. These chromitite bands.20% of Cr2O3. More than 90% of India’s reserve of about 150 mt. Several linear parallel bands and lenses of chromitite occur within the anorthosite gneiss in Sittampundi Complex for a total stretch of 12.59% of Fe2O3 and 10.31% of Al2O3. At places. 10.The reserves are estimated at 0. Important chromite occurrences are reported from Sittampundi and Mettuppalaiayam ultramafic complexes in Tamil Nadu.blogspot. The known deposits are in Maharashtra in Sindhudurg and Nagpur-Chandrapur districts. Coimbatore District has yielded 0. The estimated deposits are of 0. The mineralisation occurs in two locale:(1) Jojohatu — Hatgamaria (Singhbhum district) and (2) Sukinda (Jajpur . 24.20 to 25.04-41.43% Ni.12% have also been recorded from the Torappadi ultramafic body. amphiboles (30-35%) and rutile and other accessories (5%).78% and total iron as Fe-varying from 16. massive chromitite with 70-80% of chromite showing cumulate texture is also noticed.20% of FeO. In Mettuppalaiyam ultramafic complex. Chromite : The region south of the Singhbhum Cu-U belt is very rich in Cr mineralisation.40% Ni and occasional composite grains of Pentlandite + Pyrrhotite + Chalcopyrite have been recorded from the Red Hills. varying in width from 8 cm to a maximum of about 3 m.visit: grvmalaikalam. These chromitite bands analyse 21.Deposits in (1) were much smaller and already mined out.10 to 0. The chromitite samples collected from Solavanur and Karappadi areas have given Cr2O3 values ranging from 20.53 mt. lenses and disseminations within the meta-pyroxenite-gabbro-anorthosite sequence extending for a strike length of about 1 km with a width of about 250 m.10–13. of economic grade Cr-ores occurs in this region. Ore mineralisation at Sukinda is more intense than at Baula Nuasahi. three occurrences of chromite are reported at Karappadi.Baula Nuasahi (Keonjhar district).in The weathered profile over the Bhuvanagiri Ultramafics. Cr mineralization occurs in Ladakh in the form Chromite lenses in ophiolitic suits of rocks represented by basic and ultrabasic rocks which have been emplaced within flyschoid sediments.visit: grvmalaikalam.1995 were assessed at 86. Nagaland. Chromite is the main economic mineral of the ‘Ophiolite suite’ of rock that is similar to those of the Alpine type in their mode of occurrence.in Chromite mineralization is reported from Kyun Tso-Shurok Sumdo. Roro and Jojohatu in Bihar e. 3. Ponda and Dudsagar in Goa.04.23 million tonnes in which the shares of proved. physical (podiform) and chemical characteristics (high Cr2O3 content (>45%) and low TiO2 content). probable and possible reserves are 30%. Kondapalli in Andhra Pradesh b. Copper in the form of disseminated chalcopyrite and native specks is associated with Dras volcanic in Tal and Spiti area. in south to north-east of Chiphur in Nagaland in north.blogspot. Meso-Cainozoic mineralisation epoch associated with Indus ophiolites. Tertiary Ophiolite Association Chromite occurrences of Manipur. Sukinda and Nausahi in Orissa b. The inferred reserves have been estimated at 14000 tonnes Late Mesozoic Ophiolites of Northeast: The belt with Ophiolite suite’of rock extends for about 200 km from Moreh in Manipur. INDIA’S RESOURCES AND PRODUCTION: 1. Sinduvalli and Byrapur in Karnataka c. Leh district and Sanko area. Sittampudi complex in Tamilnadu. Over 97% of the total recoverable reserves are found in Orissa State. Bhandara and Ratnagiri in Maharashtra d. Andaman and Nicobar Islands and Jammu & Kashmir. Archean Greenstone Association a. Proterozoic Granulite Association a. 2. 36% and 34% respectively. Out of 136 . [ Important resource occurrences in India are shown in Plate – 1] Resources : Total recoverable reserves of chromite in the country as on 01. in the total recoverable reserves of all grades about 34% is of Metallurgical grade and 29% is of charge Chrome grade. RECOVERABLE RESERVES OF CHROMITE (In thousand tonnes) ______________________________________________________________________________ State / Grade Metallurgical (>48% Cr2O3) Refractory (>40% Cr2O3) Charge Chrome (>44% Cr2O3) Low Beneficiable BY STATES Recoverable Reserves ( as on 1. seams. Maharashtra accounts for the remaining 1% production. Six seams have been delineated with thickness varying from 10 to 50 m. These are friable in nature and described as brown ore. accounting for 99% of the total production in 2003-04. granular ore. ferruginous ore. 2004] B. BAULA – NAUSAHI BELT : Nausahi ultramafic complex covers a surface area of 5 sq km and a detached segment occurring at a distance of 50 km to the ENE of Sukinda area.visit: grvmalaikalam. total resources of chromite in the country as on 1. friable ore.2000 are 179 m.tons of resources (74%). Chromite occurs as persistent thick bands.663 _____________________________________________________________________________________ [Source : IBM Year Book. Production : Orissa continued to be the leading producing State of chromite.tons of insitu reserves (26%) and the remaining 132 m. Ore bodies in Nausahi sector are spread over a strike length of 3 km in N-S 137 . Category-wise. As per UNFC system.blogspot. grade-wise and state-wise break up of recoverable reserves are given in following table.6%) of chromite resources in the country are located in Orissa.Major share (98.439 12799 Karnataka 523 648 1170 Maharashtra 2 0 2 Orissa 28227 17263 45490 Manipur Tamilnadu _____________________________________________________________________________________ ALL INDIA 28752 17910 46. Production of chromite in Karnataka.4.2000) Proved Probable 8072 3464 407 448 14381 7057 5876 6923 Total 11535 855 21. disseminated ore and banded ore.4. Baula-Nausahi and similar occurrences of ultramafic rocks at Bhalukasoni and Ramgiri. lenses within ultramafic complex. Mining of chromite in Nausahi area started during 1942-43.tons comprising 47 m. The chromite deposits occur in number of localities along NE-SW belt associated with ultramafic complexes of Sukinda. The chromite deposit of Sukinda belt is mainly stratiform type and can be classified into the categories like lumpy ore. Goa and Tamil Nadu.Zone-I group of iron ore deposits occur on the Bonai Iron Ore Ranges of Jharkhand and Orissa states and in the adjoining areas in Eastern India.The width of individual band as revealed from borehole data. have been identified in the country on commercial ground . Banded Iron Formation of Pre-Cambrian Age : Extensive outcrops of BIF. varies from 15 m to as thin as 10 cm. parts of Andhra Pradesh.5 channel samples collected from pits showed the following analytical results : Cr2O3 . Reserve of 3.24% IRON ORE Major iron ore deposits in India. Zone-II group comprises the iron ore deposits in the 225 km. iron formation which is seen confined to granulite terrains. in south India. Maharashtra. The DGM.77 to 54. marbles.This is a weakly banded magnetite.24. magnetite rich banded magnetite quartzites occur in parts of Andhra Pradesh near the East Coast while in Tamilnadu good deposits of magnetite occur in Salem district and in neighbouring areas.in direction. The most common names used in India to designate BIF are Banded Haematite Quartzite (BHQ) and Banded Magnetite Quartzite (BMQ).blogspot. metavolcanics and amphibolites completely engulfed in a voluminous mass of a tonalitic gneiss. Orissa estimated a total reserve of the order of 1550 tonnes for both massive and spotted variety of chromite with Cr2O3 content from 25. Karnataka and Kerala) that 138 . Chhatisgarh.8. The formation is highly folded and metamorphosed under granulite facies condition.07 to 27. are found in the states of Jharkhand.76%.10 to 14. Ramagiri can be approached from Jeypore.quartzite forming part of a supracrustal sequence of quartzites. In addition. Bhalukasuni chromiferous ultramafic body is the only known occurrence of its kind. Orissa. which is connected with NH No. The Nausahi ores are inferior charge chrome grade. distributed in five zones designated as Zone – I to Zone-V.visit: grvmalaikalam. Iron and silica are higher than in Sukinda sector.Zone – V deposits cover iron ore of Goa state. mica schists.49% Fe(t) .43. Typical examples are iron formation from the granulite regions of South India (Tamil Nadu. Karnataka. east of famous Nausahi chromite fields. long North-south trending linear belt in central India comprising the states of Chhattisgarh and Maharashtra (East).40 million tonnes of chromite of all grades have been estimated in BaulaNausahi sector. Zone – III deposits occur in Bellary-Hospet Regions of Karnataka while the Zone – IV deposits cover the rich magnetitic deposits of Bababudan-Kudremukh area of the same state in south India. Orissa. Uttar Pradesh and Jammu-Kashmir. is the one confined to the schist belts formed during the period 2900-2600 Ma. Nagaland. Detail description of the deposits belt-wise and sectorwise has not been enumerated. These form important repositories of rich iron ore deposits in India.The occurrences of iron ore deposits are also reported from Assam.Thus the iron ore formation within the Indian shield can be divided into two main types :(i) those lying within the high grade region and (ii) those confined to Archean schist belt. West Bengal. Chhatisgarh. Maharashtra. The larger and rich iron ore deposits are mainly concentrated in Jharkhand. Important accumulations are in Singhbhum district (Jharkhand). Orissa. MANGANESE 139 . Chhattishgarh and Goa.in is different from those of the Archean schist belt. Keonjhar district (Orissa).) formed in distinct tectonic environment and later incorporated within high grade mobile belt. Sedimentary iron ore deposits of siderite and limonitic composition: These ores are also known as Bog iron deposit. These ores of siderite and limonitic compositions are found associated with the iron stone shales of lower Gondwana age occurring in the coal fields of Jharkhand and West Bengal and the ferruginous beds in the Tertiary formations of Assam and the Himalaya.The second and the more extensive type having characteristic of both Algoma and Superior type. The major ore minerals are haematite and magnetite. highly deformed and metamorphosed belt within Archean granulites and gneisses and represents formation of an older age group (>3000 Ma. But these deposits are not economically significant. Himachal Pradesh.In Ranigunj area the sedimentary iron ores occur in the form of thin beds of ironstone of variable thickness and frequently in the Ironstones shale Group of the Damuda series in Ranigunjcoalfield. Magnetite ore deposits are mainly confined to Chikmagalur district in Karnataka and Salem and North Arcot district in Tamil Nadu and Prakasam district of Andhra Pradesh. Andhra Pradesh. Kerala and Rajasthan. Bastar district (Chhatisgarh) and in Goa.visit: grvmalaikalam. Meghalaya. Titaniferous and vanadiferous magnetites: The vanadiferous-titaniferous magnetite deposits of south eastern Singhbhum (Jharkhand). These types of deposits are confined to states of Jharkhand. Tamil Nadu.In upper Assam such deposits occur in Lakhimpur and Sibsagar districts and are mainly of two types: clay iron stone and impure limonite.blogspot. Karnataka. Bellary district (Karnataka). the first type occurs as narrow.Among these. Mayurbhanj and Keonjhar (Orissa) and Hassan districts( Karnataka) are associated with gabbroid and ultrabasic rocks. Karnataka and Goa. Comparatively small deposits are situated in Maharashtra. The manganese belt in Nagpur and Bhandara districts extends for 100 km from west of Gumgaon to Ghanor in the east and passes through Paraseoni.4% of the total resources estimated for the country. rhodonite rock or both and (2) as lenticles of bands of nodules in crystalline limestone. Manganese ore in Sindhudurg district occurs as secondary enrichment deposits associated with lateritised Dharwarian metasediments. near Mansar. Madhya Pradesh is India’s foremost source of high-grade manganese ore.1 Mt of manganese which constitutes 22. The largest and richest deposit is located in Balaghat district. next to that of Karnataka.5 km northeast of Ratanpur near Newasa and Kamarakhol area of Bilaspur district of Chhattisgarh.blogspot. Andhra Pradesh contributes about 90% of the manganese ore production in the country. cryptomelane and pyrolusite. Maharashtra was the second largest producer of manganese ore. Jhabua.Maharashtra possesses about 10% of the country's total estimated resources of Manganese ore. Khargone and Seoni districts.Orissa accounts for one third of the country’s annual production of manganese and possesses the second largest recoverable manganese reserve in the country i. Jhabua. braunite. patchy or pockety deposits of varying dimensions. 50. Khargone and Seoni districts. There are as many as 55 known manganese deposits in this district. lenticular. Managanese ore minerals occur in close association with haematite and carbonates as stratiform.186 million tonnes.55 million tones) of manganese ore in the country. Other small deposits and occurrences are in Chhindwara. within various greenstone belts. sharing 26% of mineral production.3 Mt . The major share of manganese ore of this sector comes from Sausar Group Manganese ore deposits occurring in the lower part of the Sausar Group. The manganese ore here is mainly associated with kodurites of the Khondalite Group in Eastern Ghats and Penganga beds in the Pakhal Basin. Dongribuzurg and Chikla with a maximum width of 20 km in the central part. Guguldoh. Mansar.e. The ore occurs in two forms viz.in Karnataka has the largest recoverable reserves (64. The ore minerals are mostly psilomelane. There are about 20 deposits spread over a length of 45 km and with an outcrop width of about 15 km. Deposits have also been rcorded from Lada Buru and from Lanji. which are of the order of about 22. Jabalpur. Manganese minerals are found scattered on the eastern slope of a hill 1. 140 . schists and quartzites associated with spessartite-quartzite rock (gondite). Manganese ores are mined in Singhbhum district in between Noamundi and Gua and from south of Chaibasa. Goa possesses 83. The total recoverable reserve of manganese ore of all grades is estimated to be 2. Other small deposits and occurrences are in Chhindwara. Jabalpur.visit: grvmalaikalam. (1) as bands intercalated with gneisses. Alsalpari. Kandri.36 million tonnes of all grades. 03% cut-off or 5.visit: grvmalaikalam. galena and molybdenite and occasional chalcopyrite are emplaced within epidote . TUNGSTEN 141 . The resources estimated in this block are of the order of 2.in MOLYBDENUM Molybdenite mineralisation occurs in two different geological settings .079% Mo at 0. Near Karadikuttam in Dindigul District. In Velampatti South Block. some of the borehole core samples show values as high as 2000 ppm of Mo. Vellore Districts of Northern Tamil Nadu and the other in a graphite pegmatite intrusive into migmatitic gneiss of Karadikuttam area of Dindigul District.0125 to 0. intrusive into migmatitic gneiss.one associated with the alkaline group of rocks occurring in Harur-Uttangarai Belt.01% cut-off.74 million tonnes with an average grade of 0. has revealed a number of low dipping parallel quartz veins.0285% of Mo.28 million tonnes of ore with average grade 0. A reserve of 0.01% to 0. In Harur-Uttangarai Belt.hornblende gneiss.032% Mo has been estimated. A probable reserve of 86.33. The maximum thickness of the mineralised zone is one metre.05% cut-off and 0. the extension of the above said mineralized zone has been proved further north over a strike length of 0.336 million tonnes with an average grade of 0.38 km.75 million tonnes of ore with an average grade of 0. The other nine blocks existing north of Ponnaiyar River in Uttangarai Sector are being explored.03% cut off is established. which proved the depth persistence of molybdenite mineralisation upto the vertical depth of 320m.723 million tonnes with the average grade of 0. TIN.blogspot. Dharmapuri and Alangayam. Tamil Nadu. detailed work was carried out by GSI by drilling upto the fourth level over a length of 1.68 million tonnes of ore with an average grade of 0.baryte vein bearing pyrite. The Alangayam area falls in the northeastern part of the Gudiyattam Bhavani Belt and mainly consists of epidote . Detailed prospecting including scout drilling by GSI. molybdenite occurs in the form of disseminated and thin stringers in a graphite pegmatite.04% of Mo has been estimated. A number of quartz .102% Mo at 0.51%). Exploratory drilling has established about 0. In the other blocks of Harur sector.hornblende gneiss occupying the valley between the Yelagiri Hills in the west and the Javadi Hill range in the east. a tentative resource of 12. In the Velampatti Central Block. some of which assayed significant molybdenum values (0.408 tonnes with the average ranging from 0. the mineralisation is confined to the shear zone within which emplacement of quartz and carbonate veins are present.50km.064% Mo at 0.314 tonnes and possible reserve of 6.059% Mo at 0. Indicated ore reserves at Jaduguda have been estimated at 2. Tiruchirapalli District.08% uranium oxide.15%. tin is found in the form of cassiterite mineral in the pegmatites and in alluvial soil being derived from these pegmatites in Bastar district.Tungsten are known from Pauri and Almora in Uttarakhand & Sonbhadra & Hamirpur districts of UP. Uttarakhand and Lalitpur district. Bhiwani district of Haryana contains appreciable quantity of casseterite and wolframite with tin ore (0. and in Gola-Alipura area of Ajmer district of Rajasthan. Disseminations. On the basis of trench sampling 4 or 5 ore shoots upto 5 m wide are inferred.blogspot. Significant concentrations.visit: grvmalaikalam. Orissa continues to be the leading state accounting for 59% of the total bauxite production of the country Jharkhand is rich in bauxite deposits. URANIUM Singhbhum district in Jharkhand has so far remained the only place in India. about 200 to 300 ppm. Ore shoots are estimated to comprise about 20 to 30 % of the total width of the mineralised zone and are expected to have an average W content of 0. At Jagduguda. uranium occurs associated with hard compact and somewhat mylonitised chlorite-sericite schist and granular metasedimentaries. BAUXITE The deposits in AP and Orissa with a total reserve of about 1650 Mt constitute one of the largest bauxite deposits in the world. It occurs in the high 142 . In the state of Chhattisgarh. producing uranium ore. Uranium is found associated with copper mineralisation in Chamoli district.Tin values (upto 1800ppm) are associated with the mineralised zone in the Kambalipatti. are seen near Kambalipatti. Stratiform zinc-scheelite mineralisation in Sakoli belt represents the earliest phase of metallogeny in this belt In the state of Madhya Pradesh.8 Mt with an average grade of about 0. Somagiri and Rayarpatti. the mineralised zone has been traced over a strike length of about 270m with a width upto 40m. Madurai District.15% tin) of the order of 30. Uranium in Singhbhum district was first reported in 1921 by GSI. streaks and patches of scheelite are seen in the calc-granulite band occurring within pegmatoidal granite/granite body in the Karungalagudi area. the mineralised zone extends over a strike length of about 1800m but the mineral content is rather low. Tin values of 200 to 500 ppm are reported from three grab samples of quartzite from Vaiyampatti. sporadic occurrences of cassiterite have been noticed within Aravalli Supergroup intruded by granitoid rocks of Jhabua district.33 million tonnes.10 to 0. At Kambalipatti. Several ore shoots (at the cut-off grade of 0. In the Somagiri also the mineralised zone as a width of about 40m or more and is inferred to have a strike length of about 1km. In the Rayarpatti area. Tamil Nadu.05% W) are inferred. upto 2% W. Uttar Pradesh. Tosham prospect.in Extensive deposits of wollastonite are located in Khera Uparla and Bel ka Pahar areas of Pali-Sirohi districts. visit: grvmalaikalam.blogspot.in hilltops of the Chhotanagpur plateau as residual deposits. Bauxite occurs as segregated sheets, pockets, patches and lenses within laterite cappings over the traps and gneisses Extensive deposits of bauxite are found in the western Chhotanagpur plateau area falling in Lohardaga and Gumla districts and adjoining Palamau district. The reserves of high-grade bauxite, containing above 50% Al2O3 were tentatively estimated to be about 9 mt in the erstwhile Ranchi district and 1.7 mt in Palamau district. The exploration at Amtipani area (23º20' to 23º23' : 84º16' to 84º19') established an estimated reserve of 4.95 mt analyzing 48.47% Al2O3 and 5.59% SiO2 in five blocks covering 1.75 sq km. Occurrences of bauxite with laterite in Kharagpur hills, Munger district are known since long. Deposits occur on the hills at Khapra (25º10' : 86º27'), Maruk (25º11' : 86º28') and Maira (26º14' : 86º22'), of which the deposit at Maruk is the most promising bauxite occurrences.Bauxites are also reported in the high level laterite, capping the highly dissected plateau tops of Rajmahal trap rocks in the Santhal Parganas district. Bauxite with laterite occurs as capping over the Dhandraul Quartzite of the Vindhyan Supergroup near Adhaura (24º41'15": 83º37') in Rohtas district (erstwhile Shahabad district).The reserves of bauxite estimated from Andhra Pradesh are placed at 565 Mt. Bauxite occurs in association with laterite capping on Deccan Traps on the high plateaus, east of Kolhapur and Satara districts and along the low lying plateaus of the Konkan terrain in Kolaba and Ratnagiri districts. It also occurs in Kolhapur district, Raigad district, Ratnagiri district, Satara district Sindhudurg district and Thane districts of Maharashtra. The important occurrences of bauxite are located in Rakti Dadar, Nanhu Dadar, Jamuna Dadar (Mandla) , Tikuri and Tikaria (Jabalpur), Mundi Dadar, Touri Dadar, Kauwajhar Dadar (Balaghat) and also in Shahdol, Rewa, Satna, Guna, Shivpuri and Vidisha districts of M.P. High grade bauxite occur between Keshkal and Amabera (Bastar district), Phutka Pahar (Bilaspur district), plateau laterite in Khuria (Raigarh district), Bodai, Daldali, Kesmarda (Rajnandgaon district) , atop Deccan trap in Mainpat-Jamirapat and JokaLuchupat (Surguja district) and also in Durg district of Chhattisgarh state. Bauxite occur as irregular lenses / pockets and high-level laterite cappings over charnockite in the Nilgiri Hills, Shevroy Hills, Kollimalai Hills, and the Palani Hills of Tamil Nadu. The diasporic bauxite is extensively found in Jammu region. It belongs to Jangalgali Formation. The aggregate reserves of 13.40 million tones were estimated for these deposits. In recent years GSI has investigated bauxite deposits of (1) Triyath-Krul,Ransuh-Khori areas of Chakkar (192000 tonnes bauxite, 345600 tonnes alumunous clay) (2)Saro-da –Bas-Malhad area of Sangarmarg (13,26,430 tonnes pisolitic/non pisolitic bauxite,aluminous clay and kaolinite) (3) Panhasa area(total 2432000 143 visit: grvmalaikalam.blogspot.in tonnes) (4) Heimna-Gura area (219980 tonnes) and (5)Karthal-Simnigali-Lodra, Jangalgali, Sukhwalgali, Chhaparbari, Kotla areas and Mohogala areas(1.33 million tones). NON METALLIC AND INDUSTRIAL MINERALS Magnesite Prominent deposit of magnesite is located on Chalk Hills as criss-cross veins traversing dunite / peridotite in Salem District, Tamil Nadu with estimated reserves of 44 million tonnes. High grade magnesite reserve in Paintahl, near Katra are 2.5 million tonnes while 45,330 tonnes magnesite occur in Kyun tso-Shurok, Leh district. 3.48 million tonnes magnesite has been reported from Agar – Girechhina deposit, Almora district with 38% MgO; 7.9 million tonnes from Dewaldhar depoist with 38% MgO ;6.7 million tonnes from Kanda – Masauli deposite with 39.67% to 44.50% MgO; 0.01 million tonnes from Areapani prospect; 43.45 million tonnes of grade 1 magnesite deposit and 3.14 million tonnes of grade II magnesite from Pithoragarh district, UP. A reserve of 9.2 million tonnes magnesite deposit with Mg O from 37% to 44% has been reported from Bora – Agar, Pithoragarh district, UP.In Alaknanda valley, a possible reserve of 2.65 million tonnes with MgO between 38% to 41.61% from Dwing – Tapowan depoist; 6.45 million tonnes with MgO more than 43.5% from Gulabkoti- Pagnao- Mamolta- Molta deposit;1.38 million tonnes with MgO from 38% to 43.5 % from Helang deposit; 1.54 million tonnes with Mg O from 38% to 43.5% from Palla – Jhakhola – Kimana deposit; 1.31 million tonnes with Mg O 42.348% to 45.96% from Mandra – Taraktal deposit and in Nandakini valley area 5.45 million tonnes with MgO 38% to 43.5 % from Ramini deposit have been reported. Limestone Extensive deposits of cement grade limestone occur in the Himalayan states. Huge deposits of limestone of differenet industrially exploitable grades occur in Jammu and Kashmir. Extensive deposits of limestone occur in various part of the state. Reserve in these districts are - Anantnag 671 million tonnes, Baramulla 180 million tonnes, Srinagar 7.5 million tonnes, Ladakh .53 million tonnes, Kathua 45.45 million tonnes, Rajouri 12.26 million tones (probable reserve), Poonch 6.5 million tonnes and Udhampur 3.03 million tonnes. Cement grade limestone reserve of 117 million tonnes (CaO:45.22 to 47.80% and MgO:0.91%) occur in Jamkhal and Gangta Hill in Bilaspur district of Himachal Pradesh(H.P.). In Kangra district, H.P.,3 km north of Dharamshala, 17.6 million tonnes cement grade limestone of CaO 42.52% and MgO 2.04% are reported. In Mandi district 550 million tonnes reserve of cement grade limestone with CaO 34.40 to 52% and MgO 0.2 to 9.1 % are 144 visit: grvmalaikalam.blogspot.in reported. In Shimla district, H.P., tentative reserve of 1020 million tonnes is estimated in Drawal, Kariali, Jutog Thench and Suma. Cement garde limestone deposits of the order of 50.25 million tonnes are located in Ambala & Mahendergarh districts of Haryana. From Rihuita, Kolgadaiya, Sidhpur & Hanuman dhara blocks, Banda district, U.P.the limestone reserves are reported to be 66 million tonnes. From Barkot – Nutiya, Lambidhar- Hathipawn and Song valley deposits, Dehradun, limestone reserves of 38.2 million tonnes, 7 million tonnes and 146.4 million tonnes respectively, have been estimated.Substantial limestone deposits occur in Tamil Nadu both as crystalline and noncrystalline (amorphous) varieties besides corals. The bulk of limestone deposits are mainly distributed in parts of Salem, Tiruchirapalli, Karur, Madurai, Virudhunagar, Ramanathapuram, Nagapattinam, Tirunelveli, Tuticorin and Coimbatore Districts. The total reserves of crystalline limestone are 200 million tonnes of ‘Proved’ category and about 25-30 million tonnes of ‘Inferred’ category. Non-crystalline limestones are located in parts of Tiruchirapalli, Tirunelveli and Tuticorin Districts with reseve base of about 670 million tonnes of both 'proved' and 'inferred' categories.Coral limestone is found in a series of islands in Gulf of Mannar, Palk Bay and Rameswaram. From Rihuita, Kolgadaiya, Sidhpur & Hanuman dhara blocks, Banda district, the limestone reserves are reported 66 million tonnes. This is high in Mg O content. From Barkot – Nutiya, Lambidhar- Hathipawn and Song valley deposits, Dehradun, limestone reserves of 38.2 million tonnes, 7 million tonnes and 146.4 million tones respectively, have been estimated. From DeobanBazmara area, Chakrata tehsil, Uttarakhand a probable reserve of 478.43 million tonnes with 45% to 46% Ca O has been estimated. In Deoban sector, Durari Dhar deposit has 80 million tonnes with CaO ranging from 51.38 % to 53.34%, Kanasar deposit 62.5 million tonne with CaO from 47.08% to 53.05%, Deoban deposit 125 million tonnes with CaO from 45.91% to 51.22%, Aun chak deposit 98.43 million tonnes with Ca O from 49.33% to 53.1% and Osmar deposit 18 million tonnes with CaO 52.53%. In Bazmara sector, Bazmara deposit has 50 million tonne limestone with CaO from 50.56% to 53.17%, Bazmara Lani deposit 25 million tonnes with CaO from 52.27%to 53.04 %. In Pithoragarh district, Dharchula deposit has cement grade lime stone of 6.591 million tonnes with Ca O from 40.97% to 49.75% , Gangolihat deposit 91.89 million tonnes with Ca O from 46.80% and 46.40%, Rorgaon deposit 7.8 million tonnes with Ca O from 39.38% to 51.43%. In Nainital district, Betalghat – Jaurasi deposit has a reserve of 10 million tonnes with 44.% Ca O. A large deposit of limestone has been reported near Nagni in Tehri Garhwal district and 3.6 million tonnes cement grade limestone around Garur chatti area, Pauri Garhwal district. A reserve of 161.22 million tonnes with 60 million tonnes of cement grade and 30 million tones of blast furnace grade limestone has 145 Tamil Nadu . 26 million tonnes with Ca O from 42. a reserve of 0. Vindhyan rocks in Rohtas and Palamau districts. about 100 to 150 tonnes of nodules were produced annually.5km in Tiruchirapalli District. some fine-grained. The total recoverable resource of limestones of all categories and all grades has been estimated to be 1450.90 million tonnes with CaO from 43% to 44% from Chandi – Basuhari block. Rohtas limestone belt.24m was estimated. long belt in the eastern part of shear zone. Upto 1960.84 million tones in the whole of Bihar & Jharkhand Apatite and Rock Phosphate/Phosphatic nodules: Apatite is found in East and West Singhbhum district as veins emplaced in the Singhbhum Shear Zone and also as a constituent associated mineral in mica pegmatites of Bihar Mica Belt. Besides. Recoverable probable reserve of apatite in Jharkhand has been estimated as 7.3% from Gurmah – Patwadh block.50%.23% from Susnai Mahona block and 70. In Singhbhum district.48 per cent. of apatite with 15% P2O5 was estimated in 1989 by IBM.45 mt. Asbestos 146 . Munger and Palamau districts. In Pathargora.000 tonnes of apatite has been estimated with P205 content of 27. A total probable reserve of 127. later work in (1992) Pathargora has indicated a possible reserve of 3.14 to 26.89% P2O5 at 4. along a belt extending from Neykulam to Siruganpur covering an area of 27. Phosphatic nodules occur in association with gypseous clay and shale of Karai Formation of Uttattur Group of Cretaceous age. 48. in parts of Gaya.1% to 48.UP.60 million tonnes with Ca O from 42% to 45% from Kanach block. viz.. Vellore District.0% P2O5 cut-off. However. apatite occur in a 60 km. and Chhotanagpur Gneissic Complex in Hazaribagh. Ranchi. Dharmapuri District.visit: grvmalaikalam. Tamil Nadu.90 million tonnes with Ca O from 38.blogspot. non-crystalline limestone is also found within the rocks of Kolhan Group in Singhbhum district.73 Mt. 49. between Ichagarh (22º45':85º42') and Khejurdari (22º41' : 85º34'). but no production is reported at present. A total possible reserve of 178 million tones (Mt) atite of all grades in the whole of Singhbhum Shear Zone has been estimated by IBM (1998).in been reported from Kajrahat limestone belt. The P205 content of the nodules varies from 21.27 Mt. of apatite with average grade of 11. Hazaribagh and Munger districts.In the carbonatite near Sevattur. Rohtas limesote belt. Limestone deposits in Bihar and Jharknand are mainly associated with two different groups of rocks. apatite crystals are disseminated and a reserve of 190. Sonbhadra district. Small crystals of apatite have been noted in hybrid rocks (syenite-pyroxenite) in the Hogenekal area.000 tonnes of these nodules upto a depth of 15. . near Wenganur and Kandodi in Garhchiroli District of Maharashtra. LIGNITE. 147 .2007. Bokaro. Stibnite Stibnite reserve of the order of 10.blogspot.in Asbestos occurrence in Jharkhand are almost entirely confined to the East and West Singhbhum districts and are associated with Precambrian basic and ultrabasic rocks. Although both crysotile and amphibole varieties are found. Tremolite type being the most common crysotile variety occurs at Roro (22º39'30":85º30'30"). 13km south of Namakkal and Allanganathan in Namakkal District and at Kargudi in Karur District of Tamil Nadu. Narshingpur. Coal Resources of Bihar is 160 milliom tones and Jharkhand is 74313.65% Sb) occur at Bara Shingri in Lahaul & Spiti districts of Himachal Pradesh. Schore Sconi and sidhi district of Madhya Pradesh. Other occurrences of borax have been noted at Chumathang. the leading State in the Indian subcontinent in respect of its solid fossil fuel content. A total reserve of all categories of asbestos in whole of Jharkhand has been estimated to be of the order of 0. Nurda (22º20':85º44'). the majority of the occurrences are mainly of amphibole variety.01. Out of different Gondwana basins of Peninsular India. Ramgarh. Karanpura. Yang and Mahe areas of Leh district. Bichaburu (27º17'30":85º48'00") and Manpur (22º36':86º16'). OIL and GAS (FOSSIL FUEL) Jharkhand. to the west of Barakar River and a small area in trans-Ajay part). COAL. especially where the latter have been serpentinised.visit: grvmalaikalam. Auranga and Hutar from east to west are included in EW trending Damodar-Koel valley basin belt.155 Mt. The coalfields like Raniganj (western part. Jharia. Minor occurrences of asbestos have been reported between and Kolgaon in Sindhudurg District. near Tumkhera khurd in Bhandara District. Borax The net reserves of crude borax in Puga valley have been estimated 5423 tonnes. Asbestos occurs at Goreghat (Balaghat District). Badagaon and Khemra (Betul district ).64 million tonnes as on 01. Kalimati (22º16'00":85º35'30"). Amphibole asbestos has been noted near Bargur and Muddampalayam in Coimbatore District. bears the testimony of classical development of the Permian coal measures. Chusul. Dhantalab (Dewas district) Abdia (Hoshangabad district ) and in minor quantity in Mandsaur. the newly redefined Jharkhand State of erstwhile Bihar occupy the most important Damodar-Koel valley basin belt along with a subsidiary basin chain to the north of it and the Rajmahal group of basins (a part of Rajmahal-Purnea master basin).582 tonnes (1. Perambalur. through Neyveli. Thus prognosticated gas-in-place reserves of 281 Billion cubic meter (BCM) (at equilibrated pressure under saturated reservoir condition) were derived from prospective areas of Bihar and Jharkhand coalfields.P. Srimushnam. The lignite belt in the Cauvery Basin of Tamil Nadu. Chirimiri coal field. Johilla coalfield. Singrauli coalfield of Sidhi district in the state of M. about 130km long and 5 to 15km wide. Baramulla district. Sonhat coalfield (Koriya district) and Bisrampur coalfields. extends from Bahur in the north.84 million tones. Hasdo-Arang coal field. Besides these two large coalfields.9 million tonnes). Estimated reserve are at Jangalgali (4.blogspot.The total Coal resourse of West Bengal is 28334. Umaria and Korar coalfields of Narsinghpur district. the Geological Survey of India carried out an exercise for prognostication of possible gasin-places reserves (Coal Bed Methane) in selected areas of few coalfields containing high rank coal under cover of younger sediments. Chinkah (3. Down dip extension of this lignite zone is reported from ONGC boreholes from 500m to 1800m depth in Tiruvarur. Jhilmili coalfield. The important coal fields are 1) Wardha Valley Coalfield (Chandrapur District) and Kamthi-Saoner Coalfield (Nagpur District) of Maharashtra state. 3) Pench-Kanhan-Tawa coalfields in Betul-Chhindwara and Hoshangabad districts. Satpura-Son basin. Barjora. Few deposits of lignite of the order of 7. there are a few minor coalfields and/or outliers of coal bearing rocks.Semi-anthracitic coal deposits are located in various part of Udhampur & Rajour districts of Jammu region. gas desorption data.25 million tonnes) and Jigni-Kura (0. Kamalapuram. and Wardha valley basin . Jayamkondacholapuram and up to Mannargudi in the south . Nagappattinam and Thanjavur Districts of Tamil Nadu.visit: grvmalaikalam. Till date. wherever available.falling in parts of Union Territory of Pondicherry and Cuddalore. Lakhanpur coalfields and Tatapani coalfields (Surguja district) in Chhattisgarh state. Attempt was made to make the estimate more realistic by reconciling empirical calculations of methane content with actual gas emission. published or otherwise. Mand-Raigarh coal fields (Raigarh-Jashpur districts). Metka (2. During the last 10-12 years. Important coalfields of central region include coalfields of Mahanadi basin.7 million tones).18 million tonnes). like Darjeeling. Recently. The lignite occurs as a subcrop at depth ranging from 50m to 500m below ground level.The coal is generally non-coking and high in moisture. Mohpani coalfield. 2) Korba coal field. Sohagpur coal field. Sendurgarh coal field (Bilaspur and Korba districts). 148 . Hetampur and Tangsuli in West Bengal. Raniganj coalfield is the only coal producing area of the State.26 million tonnes are reported in Nichahom and Chowkibal. the Birbhum coalfield has been discovered.in Raniganj coalfield of West Bengal holds the earliest known coalfield of the country. north of Kollidam River whereas. GSI has proved 4. Flaky graphite has been noted near Borakonde and Kamaram in Bastar district. respectively.visit: grvmalaikalam. Exploration of these deposits are being carried out by GSI. Exploratory work by ONGC indicated possible occurrences of lignite at 800m – 1400m depth level in the Kalol basin.5 million tonnes of lignite reserves upto a depth of 36. Kartpadar and Limpara in Raipur district of Chhattisgarh state.Major occurrences of Lignite in Gujarat are in the Panandro Lignite field and adjoining areas of Kachh district and in the Bhuri – Rajpandi area of Bharach district. which has 600 and 1470MW generation capacity. MECL & DMG Rajasthan.blogspot. In the Bastar district of Chhattisgarh state. Sustantial deposits of lignite occur in the Tertiary formations of Middle Eocene area in the Barmer – Jaisalmer Palana and Nagaur basins of Barmer/Jaisalmer. Bhandara and Gadchiroli districts of Maharashtra. The estimated reserve of lignite is about 6500 million tonnes and 18. Flaky ghaphite is noted near Borakonde and SW of Kamaram. graphite occurs associated with quartzite and diopside gneiss on the west bank of Sabari river. The lignite occurs within Tertiary formations of Eocene age.in Kovilkalappal and Mayiladurai. GRAPHITE Graphite occurrences are reported from Sindhudurg. Bikaner – Nagaur districts. It is being mined by Neyveli Lignite Corporation Limited and the mined lignite is utilised in thermal plants I&II. 1 to 90 m thick (cumulative thickness) in the Mannargudi area. Significant prospects of oil and natural gas have been identified over an area of about 40.Graphite occurrence is located in Puvandhi in Sivaganga District. Graphite is also reported from the khondalites near Kartpadar and Limpara (Raipur district) and as lenses in association with quartzites and schists at Kennapara. Lignite zone is 1 to 25 m thick with an average of 12m.000 million tonnes in the area north and south of Kollidam River. respectively. Sizeable deposits of Lignite are reported from Hundwara tehsil of Baramulla districts. Manikpur. Kurinjankulam in Tirunelveli District. Kobi and Tolkipara areas of Surguja district. south of Kollidam River.000 km2 on-shore and off-shore in the Krishna-Godavari basins in parts of East and West Godavari and Krishna districts. Specks of graphite are reported from Palachelama and Bote Tongu.5 m in Nichahom and Chowkibal areas of J & K. Nagaur and Barmer districts. Rajasthan has good deposits of lignite in Bikaner. NLC. Palakottai Hill and near Pudupalaiyam in 149 . Chiklar.75.In the state of Madhya Pradesh. 2. ilmenite and garnet sands occur along the coast of Karaikal with reserves of 17. 1.Graphite is reported from Almora and Pauri Garhwal districts in the Himalaya and Hamirpur district in Uttar Pradesh. Rutile. The Chavara heavy mineral deposit extends in the north to sandy beach west of Nirkunnam to south of Trikkunnapuzha in Alappuzha District. Gypsum 150 . in the graphite schist from Jobat. graphite is found associated with graphite schist and phyllite of Tikari.7 million tonnes graphite has been estimated upto a depth 3 m. Maramjhiri. Monazite and Garnet sands: Tamil Nadu has major heavy mineral deposit (Ilmenite. Reserves are estimated of over 0. Gauthana.60.07 million tonnes.093 tonnes of heavy mineral deposit have been estimated between Periaswamipuram and Vembar Naripaiyur in Ramanathapuram District. major concentration of these heavy minerals occur along east coast between Kolachal and Kanyakumari in Kanyakumari district with reserves of 45.862 tonnes (AMD). Jowari Moti and Kalapan areas of Jhabua district and in carbonaceous shale of Morar Formation near Chalgaon and Chattgurhi near Behat of Gwalior district. Apart from these. Rutile.26. Ilmenite.06 million tonnes and Sillimanite0.in Vellore District and Tirumangalam. the coastal tract between south of Ponnani to Balangod is endowed with 9. as reported by Atomic Minerals Division (AMD). In Malappuram District.Ponnamangalam in Madurai District.3 million tonnes in the inner shelf areas of Kollam-Varkala sector.9 million tonnes. Rutile. Monazite and Garnet sands) associated with the beach sands spread along its vast coastal tracts. Zircon-0.000 tonnes of magnetite. Tampura. The AMD has estimated a reserve of 3. The heavy mineral deposits of Kerala are mostly dominated by ilmenite and monazite confined to sandy beaches of coastal stretches of Varkala and Chavara in Kollam District. These deposits are being worked by the Kerala Minerals and Metals Ltd. and Indian Rare Earths Ltd.000 tonnes of garnet and 4000 tonnes of zircon.From Kalimati and Sirar areas of Almora district. The Thiruvananthapuram District deposit of ilmenite and monazite in beach sands are found in Vizhinjam. Apart from these GSI has proved the probable resources of Ilmenite-0.33 million tonnes of heavies from these areas out of which ilmenite constitutes a reserve of 2 million tonnes. Bhopali.visit: grvmalaikalam.605 tonnes..000 tonnes of ilmenite. 93. In the Union Territory of Pondicherry. Kovalam and near Veli and Varkala.30.80. Junawani and Golighat areas in Betul district.15. a possible reserve of 10.6 million tonnes of graphite concentrate in Tamil Nadu.blogspot.Graphite also occurs in Doda and Baramula districts (probable reserve of 16 million tonnes)ofJ& K. Barmer (Utarlai. Gypsum occurs as lump in Ambala district.19 million tones of ore with an average grade of 7. Pauri Garwhal district. Uttarakahd.87% P2O5 have been 151 . Lakha. Gypsum deposits are known from Dehradun. Baramulla district (63. Tamil Nadu.62% P2O5. Deradun district. This reserve also contains 0. Gypsum reserve from Manjhara area (13209 tonnes). A probable reserve of 0.066 lakhs tones). Deogarh. Mahipur (2032 tonnes) and from Rangargaon (30481 tonnes) have been estimated. At Beldih reserve of 4. Nachna. and Churu district (Bhallan. Sri Ganganagar district ( Siramsar.862 million tones of ore with an average grade of 10. upto a depth of 15 m. The lensoid apatite zone has been delineated over a strike length of 350 m in Mednitanr. Garur chatti area (1. a total of 4. Thob. Bhaddara.58% P2O5 has been estimated up to a vertical depth of 50 m and in the eastern sector 0. Hamirwali Wadi. Suratgarh.39% P2O5. Nainital. Hanumangarh.Gypsum deposits are located in Uri.25 million tones of ore with average grade of 10.74 million tones of ore with average grade of 7. Chittar ka Par areas).blogspot.26 million tones of ore with average 8. Desli.17% P2O5 has been estimated up to a depth of 150 m which includes high grade reserve of 1. Phalsund.00% P2O5 has been estimated for a vertical depth of 50 m. Pauri Garhwal and Tehri Garhwal districts of Uttarakhand & Hamirpur & Jhansi districts of Uttar Pradesh. Borasar Malkisar. In Kutni. Large gypsum deposits of the order of 100 million tonnes occur between Liwa Thach and Kapus in Kinnaur district of Himachal Pradesh. Dhirera. Kharari chatti area (1.60 million tones are reported from Perambalur in Perambalur District and Lalgudi Taluk in Tiruchirapalli District.26% P2O5 has been estimated up to a vertical depth of 50 m.585 lakcs tones). areas).83 million tonnes). Kaoni. and it is located mainly in Bikaner district (Jamsar. a probable reserve of 0. Lunkaransar areas). Karnisar. Jaisalmer (Sri Mohangarh. Apatite-quartz rock occurs on surface only as float ore boulders..Gugthani (5080 tonnes). Raghunathpura. The apatite ore contains high Nb-content which may be recovered as by-product. Gypsum reserves of 15.33% P2O5 has been estimated up to a vertical depth of 100 m. Dhakoria areas).56 million tones of ore containing an average grade of 13. and Ramban-Batote–Assar belt (41 million tonnes) of J & K. Apatite The important apatite occurrences are located in Beldih and Mednitanr in the western part and Chirugora. mahala. At Chirugora. Shethon areas) of Rajasthan. Uttarakhand. Kavas. Tehri Garhwal district. Purtaha Kutni and Dandodih-Gamardih in the eastern part of West Bengal.in Rajasthan accounts for about 90% of total production of gypsum in the country.visit: grvmalaikalam.521 million tones of ore with an average 7. Haryana. Pallu. At Purtaha. Bharru. a reserve of 1. Satta Sunde and Nokh areas).56 million tones of ore with an average grade of 21. Nagaur district (bhadwasi. The reserve also includes 1.04% P2O5.11 million tones with 25. distributed in East Godavari. Visakhapatnam and Vizianagaram districts.29 million tones of ore with 12. The apatite mineralisation appears to extend over a strike length of around 300 m.in estimated up to a vertical depth of 100 m. In Dandodih-Gamardih.04% P2O5 have been estimated up to a vertical depth of 50 m. Along the North Purulia shear zone. a total of 4.22% P2O5 and 0. Precious and Semi-precious Stones A number of occurrences of precious and semiprecious stones are known from gemstone belt in the Eastern Ghats. apatite-magnetite-quartz rock is reported to occur at Pankridih in the northern part of Purulia district. 152 .blogspot.48 million tones of ore with average grade of 8.visit: grvmalaikalam.