||5,49,000 sq km
||Rajasthan,Gujarat and parts of Madhya Pradesh
||Regional Centre for Exploration and Research,AMD Complex,Sector-5 Extension,Pratap Nagar,Sanganer,Jaipur – 302033 (Rajasthan)
||Dr. B.S. Bisht, Regional Director
Ph : 0141-2795401
Fax : 0141-2795488, 0141-2795489
e-mail : email@example.com
The Region was set up initially as North Western Region in 1988 with headquarters at Jaipur, Rajasthan, when it was originally carved out of Northern Region. It was later re-designated as Western Region. Presently, the Region has its own office-cum-laboratory complex and residential quarters at Jaipur, catering to the requirements of officers and staff.
The following are the broad geological domains in which activities of Western Region are focussed.
(i) Archaean Basement Rocks (>2500 Ma):
The Banded Gneissic Complex (BGC) with enclaves of amphibolites and intrusive granitoids such as Untala Granite, Gingla Granite, Berach Granite, etc form the basement for Aravalli and other younger meta-sediments.
(ii) Palaeoproterozoic Aravalli Supergroup:
The rocks of Aravalli Supergroup deposited in rift related basins form the most prominent geological feature. The Aravallis consist of conglomerate, arkose, greywacke, quartzite, carbon phyllite, marble etc. These rocks are well known for their polyphase folding and multiple deformations. Some synkinematic granitic bodies e.g. Darwal Granite, Amet Granite are emplaced into it. Several Aravalli equivalent basins like Jahazpur, Pur-Banera, etc. also form part of the Palaeoproterozoic sequence of the Region.
(iii) Meso-Neoproterozoic Delhi Supergroup and equivalents:
The succeeding Delhi Fold Belt comprises limestone, quartzite, arkose, quartz-mica schist and contemporaneous volcanic rocks. These rocks were deposited mostly in northeastern parts of Rajasthan and are intensely folded with emplacement of several granitoids.
(iv) Neoproterozoic and younger rocks of Western Rajasthan:
A number of younger (~800 Ma) intrusive/ extrusive bodies belonging to the Erinpura and Malani Igneous Suite (MIS) occur in the western part of Rajasthan. Marwar Supergroup of rocks comprising mostly arenaceous and mixed arenaceous - argillaceous rocks was deposited over the MIS.
Besides, the rocks of Neoproterozoic Vindhyan Supergroup and Deccan Traps of Mesozoic age occupy small parts of the Region.
A major part of investigations have been directed to locate metasomatite, surficial and metamorphite types of uranium deposits in Proterozoic and younger basins. Some of the uranium deposits identified in the Region are: /p>
Umra – Udaisagar:
It is a metamorphite type deposit located along Umra-Udaisagar-Kalamagra tract in Udaipur district, Rajasthan. The host rocks are calcareous/carbonaceous phyllites and dolomites of Aravalli Supergroup. The ore bodies occur over 650m strike length in Umra main and 750m in Umra north-east blocks and extend up to vertical depths of 315m and 400m respectively. This area is being re-investigated for unconformity-type of uranium mineralisation.
It is a metasomatite type deposit located in Sikar district, Rajasthan. The deposit occurs along a NNE-SSW trending zone of extensive albitisation in the North Delhi Fold Belt. The host rocks are albitised biotite schist and quartzite of Ajabgarh Group (Delhi Supergroup). The ore bodies occur over 1,850m strike length and extend up to a vertical depth of 650m. Exploration in contiguous blocks is in progress.
It is located in Jhunjhunu district, Rajasthan, about 120 km NNW of Jaipur. This deposit also lies along the albitite line of North Delhi Fold Belt. Exploration is progressing in contiguous areas of Jahaz.
Thrust areas of Investigations:
The following geological environments are the main thrust areas for uranium exploration:
(a) Metasomatite type uranium deposits: The zone of albitisation in North Delhi Fold Belt is considered as potential for Metasomatite type uranium mineralisation. Exploration is being carried out along the albitite line of NDFB to prove uranium deposits similar to Rohil and Jahaz.
(b) Unconformity-type uranium deposits:The Paleoproterozoic Aravalli-Delhi metasediments and Neoproterozoic Marwar Supergroup of rocks are considered as potential horizons for hosting uranium mineralisation.
(c) Sandstone type uranium deposits: The pericratonic Jaisalmer Basin occupying 42,000 sq km in parts of Jaisalmer and Barmer districts, Rajasthan overlying predominantly granites and rhyolites of Malani Igneous Suite comprises Lower Jurassic, fluvio-deltaic Lathi formation which has been identified to be potential for sandstone type mineralisation.
(d) Surficial type uranium deposits (Calcrete/ playa): Physiography and climatic conditions of western Rajasthan along with favourable geological setting associated with restricted drainage systems form an ideal set up for exploration of Surficial-type uranium and lithium deposits.
(e) Rare Metal & Rare Earth (RM&RE) Investigations: The Neoproterozoic Siwana Ring complex of southwest Rajasthan and the Ambadongar Carbonatite Complex in Chhota Udepur district, Gujarat have been identified to be potential for RM & RE minerals. The exploration for Rare Metals & Rare Earths (RM&RE) is in progress both at Siwana Ring Complex, Barmer district, Rajasthan and Ambadongar Carbonatite Complex, Chhota Udepur district, Gujarat. In addition, a number of columbite-tantalite, beryl, lepidolite-bearing pegmatite occurrences have been located in Rajasthan Mica Belt at Deoria, Sangwa, Lakhola, Soniana and Danta-Bhunas.
The Region has the following analytical laboratories