||4,38,000 sq km
||Bihar,Jharkhand, Orissa,W.Bengal and Sikkim
||Regional Centre for Exploration and Research, AMD Complex, Khasmahal,P.O.: Tatanagar, Dist. East Singhbhum, Jharkhand - 831002.
||Anirban Saha, Regional Director
Ph. : 0657-2299807
Fax : 0657-2297689
Email : email@example.com
Eastern Region was set up during 1959 with headquarter at Kolkata. Subsequently the head quarter was shifted from Kolkata to Jamshedpur in its own premises during 1994. The major thrust of uranium exploration has been in the Singhbhum shear zone. The first uranium deposit of the country was established at Jaduguda in 1951. Subsequently, other uranium deposits like Bhatin, Narwapahar, Turamdih, Bagjata, Mohuldih, etc. were established.
Broad Geological Features
Broadly following geological domains occupy major parts of Eastern Region.
(i) Archaean basement gneiss and Proterozoic and other sediments are predominant in the states of Jharkhand, Odisha and West Bengal. The oldest rock (3800 Ma) found in India (Champua gneiss) occurs in this geological domain. The Archaean basement is overlain by Iron ore group (IOG) of rocks of Odisha and Jharkhand.
(ii) Proterozoic sediments and granites : Prominent among them are
-Singhbhum Thrust Belt Lower Proterozoic rocks comprising Singhbhum group of metasediments and Singhbhum granites.
-Dhanjori and IOG Basins – Meso-Archaean to Palaeo-Proterozoic metasediments.
-Eastern Ghat Mobile Belt rocks comprising mostly Khondalites.
Middle to Upper Proterozoic metasediments of Gangpur,Kolhan and Kunjar basins.
-Rocks of extra peninsular region in the Sikkim Himalayas.
(iii) Gondwana Sediments in Damodar, Mahanadi rift basins.
(iv) Inland and beach placers of Quaternary period.
Summary of Investigations: Important finds
Singhbhum province was well known during pre-independence period for its mineral wealth, particularly copper deposits. Soon after the formation of AMD, radiometric surveys in this province resulted in identifying hydrothermal vein type of uranium mineralisation hosted in chlorite schists + apatite, magnetite quartzites at many locations; some of which have turned out to be economically viable deposits. The uranium occurrences are spread over 180 km long arcuate Singhbhum Shear Zone (SSZ). The important deposits are as follows.
a) Jaduguda : Located in East Singhbhum district, the first place where exploration followed by exploratory mining was undertaken. Soon after, commercial exploitation was undertaken by UCIL in 1967. Mining is still in progress and mineralisation has been found to continue beyond 900 meters vertical depth. Here the mineralisation is associated with conglomerate and chlorite schist of Singhbhum group of Proterozoic age.
b) Bhatin : It lies 3 km west of Jaduguda along the Singhbhum Shear Zone. Mineralisation is associated with quartzite and biotite chlorite schist. Mining is in progress.
c) Narwapahar : It lies 10 km west of Jaduguda along the Singhbhum Shear Zone. The host rock for uranium mineralisation is chlorite-quartz schist and the mineralisation is spread over 2000 meters strike length. Currently this deposit is under exploitation by UCIL.
d) Turamdih : A cluster of deposits (Turamdih-East, Turamdih-South, Keruadurgri) occur in proximity to each other at Turamdih located nearly 24 km west of Jaduguda. Uranium mineralisation is associated with chlorite quartz schist. At Turamdih (East) the mineralisation is spread over 2 km X 1 km area and the entire resource occurs within a vertical depth of 200m. Mining of Turamdih (East) deposit is in progress by UCIL.
e) Banduhurang: Turamdih West is known as Banduhurang deposit. The deposit is being exploited by UCIL by open cast mining.
f) Mohuldih : It is located 5 km west of Turamdih. The host rock is tourmaline bearing quartz schist, quartzite and chlorite quartz schist. Mineralisation is established over 1 km strike length and within a vertical depth of 250 m. Mining by UCIL has commenced from April 2012.
g) Bagjata : It is located nearly 25 km southeast of Jaduguda. Uranium mineralisation is hosted by quartz chlorite biotite schist. The mineralisation is spread over 450 m strike length with a vertical persistence of 260 m. Mining by UCIL has commenced in 2008.
Other smaller uranium deposits along this shear zone, in a similar geological set up are (i) Banadungri-Singridungri (ii) Kanyaluka (iii) Nimdih (iv) Garadih and (v) Rajgaon.
Uranium was also found in copper tailings of Cu minerals (Rakha Mines) containing about 100 ppm of eU3O8. This resource was also used for extraction of uranium by setting up recovery units for treatment of the tailings.
Apart from uranium, rich resources of xenotime (mineral containing heavy REE) associated with garnetiferous biotite schist of Singhbhum group of rocks was also located at Kanyaluka.
Quartz Pebble Conglomerate hosted uranium mineralization have also been located at a number of places at the base of the Iron Ore Group (IOG) and Dhanjori basins. Important localities are Butgora, Phuljari, Chakri in Jharkhand and Sayamba, Taldih in Odisha.
Present thrust areas of Investigations
Uranium exploration programme in parts of Eastern Region currently gives emphasis for identification of (i) hydrothermal vein type uranium deposits in Singhbhum Shear Zone and South Purulia Shear Zone (ii) Unconformity type uranium mineralisation in Middle to Upper Proterozoic Chhattisgarh Basin and (iii) Quartz Pebble Conglomerate type of uranium deposits in Daitari-Tomka, Deogarh- Mankarhachua basins of Odisha.
Singhbhum Shear Zone (SSZ) is the known uranium province in the country hosting a number of uranium deposits, a few of which are presently under production by UCIL. Exploratory drilling is continued in Narwapahar-Banadungri-Singridungri-Garadih sector and Bangurdih areas to delineate the ore bodies and assess the deposits in terms of its geometry, grade and reserve.
Along South Purulia Shear Zone (SPSZ) places like Tamar, Kantaldih, Beldih, Kutni, Porapahar and Thakurdungri, etc. hosted by Singhbhum group of rocks, proximal to structural lineaments, a number of hydro- and pedo- U anomalous zones in both Singhbhum Group and Chhotanagpur Granite Gneiss Complex (CGGC) in the vicinity of SPSZ, associated with prominent fracture trends are delineated. Subsurface exploration has established lean mineralization in Beldih-Bhawanipur and Kutni-Dandudih areas. Within SPSZ and Chandil formation, several EM conductors of various strength are identified of which few are taken up for subsurface validation.
The Quartz Pebble Conglomerate (QPC)Palaeo-Proterozoic supracrustals of Singhbhum craton in Jharkhand and Odisha are found favourable and exploration efforts are continued since 1980. The first occurrence was reportedfrom Dhanjori basin in 1983. Later efforts led to the discovery of a number of uraniferous Quartz Pebble Conglomerate occurrences in Daitari-Tomka, Koira-Noamundi, Badampahar-Gorumahisani, Notopahar, Malaygiri-Bankhol, Mankarhachuan and Deogarh basins of Iron Ore Group in Singhbhum-Odisha Craton.This QPC hosted uranium mineralization is also associated with precious metals like Gold, Silver and Platinum Group of Elements (PGE). Basinwise details of Uraniferous QPC areas are as follows:
a). Mankarhachua area: The area is located north of Pallahara, Angul district, Odisha around western margin of Singhbhum craton. The uraniferous Quartz Pebble Conglomerate horizons are exposed over an appreciable strike length intermittently from Timi in east to Gurusanga in west having best exposures around Mankarhachua village. This horizon is unconformably overlying Pallahara granite gneiss along southern margin of the basin. This QPC hosted uranium mineralization is also associated with significant content of precious metals like Gold, Silver and PGE.
b). Balia-Rankia-Talangi area: The area is located in Mahagiri synform near Sukinda valley around southern margin of Daitari-Tomka IOG basin at southern part of Singhbhum-Odisha craton in Jajpur district, Odisha. The uraniferous QPC occurrences are exposed over appreciable strike length from Balia to Kakudia in southern limb and Kansa to Talangi in northern limb of Mahagiri synform, lying unconformably over Archaean granite-greenstone basement of Singhbhum-Odisha craton. Subsurface continuity of low grade QPC hosted uranium mineralization has also been established over appreciable strike length in southern limb of Mahagiri synform.
c). Birtola-Phuljhari Pahar-Bagiyabahal area: The area is located near the base of the Koira-Noamundi Iron Ore Group sequence along the northwestern margin of Bonai Granitic Complex in Sundergarh district, Odisha. The uraniferous QPC occurs as three interbedded lensoidal bands with varying dimensions within the basal part of IOG sequence and are exposed over appreciable strike length. Association of gold (Au) with uranium mineralization has enhanced the scope of investigation of the area for other metals.
Middle to Upper Proterozoic Chhatisgarh basin
Middle to Upper Proterozoic Chhatisgarh basin is located at the northern fringe of Bastar craton while eastern part of the basin falling in Eastern Region is located in western part of Odisha and eastern part of Chhatisgarh. The geologic and tectonic framework of the eastern Chhatisgarh basin is found to be favourable for unconformity-related uranium mineralization. Uranium exploration commenced in 1980’s and so far more than forty sizeable uranium occurrences in association with polymetallic sulphides are located in this part in the vicinity of Middle Proterozoic unconformity between basement Sambalpur granitoid and overlying Chhattisgarh cover sediments. In present scenario, Singhora protobasin is the main target for uranium investigation.
The region is equipped with following laboratory facilities.
Remote Sensing Laboratory