Informatics Publishing Limited

Utpal Bose ¹

Affiliations
1 Geological Survey of India, D-87, Meera Marg, Jaipur 6, IN

Abstract

No Abstract.

Full Text

   

S. P. Singh ¹, Utpal Bose ²

Affiliations
1 23, Commerce College, Professors' Colony, Chitragupta Nagar, Patna 800020, IN
2 B-16 (A), Chomu House, Jaipur 302001, IN

Abstract

Trace fossils of trail markings and burrows are reported from the Alwar and Ajabgarh metasediments of the Proterozoic Delhi Supergroup from several localities of northeastern Rajasthan.

Full Text

   

P. Gupta ¹, K. Mukhopadhyay ¹, Utpal Bose ¹

Affiliations
1 Geological Survey of India, IN

Abstract

The Proterozoic Delhi Supergroup of rocks along the Aravalli orographic axis in central Rajasthan encloses thick linear piles of syn-sedimentary volcanics. The volcanies are low-potassic oceanic tholeiites derived from mantle source. The repository basin was ensialic to start with and was partially rifted to facilitate magma upwelling concomitant with sedimentation. Structural stratigraphic and chemical characters of the volcanics militate against the possibility of its being allochthonous slices of an oceanic crust.

Full Text

     

Utpal Bose ¹, Fareeduddin ¹, M. S. Reddy ¹

Affiliations
1 Geological Survey of India, Regional Geology Division II (Operation: Rajasthan), Jhalana Dungri, Jaipur 302 004, IN

Abstract

The Proterozoic South Delhi Fold Belt (SDFB) is known to have a dominant volcanic component along the western flank of the Aravalli Range. Earlier studies have indicated both bimodal and unimodal characters of these volcanics in different parts of the SDFB. The Shyopura-Narpura area in north-central part of the Aravalli Range has, on the other hand, volcanics of intermediate and ultrabasic composition, interlayered with basic and felsic volcanics. This polymodal suite of secondary greenstone character is interpreted to have erupted in a rifted back-arc setting.

Keywords

Geochemistry, Delhi Fold Belt, Volcanism, Rajasthan.

Full Text

     

Utpal Bose ¹, A. K. Sharma ¹

Affiliations
1 Regional Geology Division II, Operation: Rajasthan, Geological Survey of India, Jhalana Dungri, Jaipur 302004, IN

Abstract

An arcuate belt of Precambrian vo1cano-sedimentaries, designated as the Hindoli Group, is sandwiched between the cratonic Archaean Banded Gneissic Complex terrain and the platformal Vindhyan sediments. Turbidites of mainly quartz wacke and petites with interlayered lava flows and tuffs of basalt, basaltic andesite and daciterhyodacite composition constitute the bulk of the Hindoli vo1cano~sedimentaries. These are interpreted to have been deposited in a continent-marginal basin with active participation of an arc system. Toward the end of the basin evolutioo; the continent-margin acted passively when quartzarenite and carbonates were deposited in a stable shelf regime.

Keywords

Hindoli Group, Precambrian, Turbidites, Continent-Marginal Basin, Rajasthan.

Full Text

     

Utpal Bose ¹, A. K. Mathur ¹, K. C. Sahoo ², S. Bhattacharya ¹, Krishan Dutt ¹, V. Aneel Kumar ³, S. S. Sarkar ¹, S. Chowdhury ¹, I. Chowdhury ¹

Affiliations
1 Geological Survey of India, Jhalana Dungri, Jaipur - 302 004, IN
2 Geological Survey of India, Bhubaneswar - 751 012, IN
3 Geological Survey of India, Hyderabad - 500 660, IN

Abstract

The oldest cratonic nucleus pf the Western Indian shield, familiarly known as the Banded Gneissic Complex (BGC), occupies a large tract in the Mcwar plains of South Rajasthan. It has essentially an old gneissic component (3.3 Ga) and a host of mafic bodies associated with detrital and chemogenic sediments which have been subjected to multiple phases of anatexis and granite intrusions (2.9 Ga and later events). The emplacement of Berach granite and succeeding dolerite dyke swarms mark the end-Archaean cratonization process. This also initiated intracratonic and cratonmarginal basin formation.

Later magmatism, especially along the basement-cover interface. is due to local remobilisation of the basement at the time of Proterozoic orogeny.

Keywords

Banded Gneissic Complex, Stratigraphy, Petrochemistry, Rajasthan.

Full Text

     

Utpal Bose ¹, A. K. Sharma ², A. Om Kumar ³, S. K. Minda ⁴, S. Banerjee ⁴

Affiliations
1 OSI, NH-5P, Faridabad-121001, IN
2 GSI, Jhalana Dungri, Jaipur-302004, IN
3 GSI, Bandlaguda, Hyderabad-500660, IN
4 Govt. of Rajasthan, Udaipur, IN

Abstract

Felsic volcanics of rhyodacitic composition have recently been recorded in the Late Archaean Berach granite massif underlying the eastern flank of the Hindoli volcano sedimentaries in southeastern Rajasthan. Feldspar-phyric lava flows and lapilli-bearing pyroclastics are the two main volcanic components.

Keywords

Felsic Volcanics, Berach Granite, Hindoli Group, Rajasthan.

Full Text