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S. Sarangi ¹, A. Sarkar ¹, S. K. Bhattacharya ², A. K. Ray ³

Affiliations
1 Department of Applied Geology, Indian School of Mines, Dhanbad-826004, IN
2 Physical Research Laboratory, Navarangpura, Ahmedabad-380009, IN
3 Department of Geology, Presidency College, Calcutta-700073, IN

Abstract

High resolution oxygen isotope analysis of samples from two different Eocene Oligocene Boundary (EOB) sections of Wagapadhar and Waior of Kutch area and their correlation with DSDP sites indicate continuity of sedimentation at these sites. A rapid cooling of -6°C across the EOB, synchronous with extinction of Eocene larger benthic foraminifera, is also observed.

Keywords

Isotope, Eocene-Oligocene Boundary, Kutch, Gujarat.

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S. Sarangi ¹, K. Gopalan ¹, A. B. Roy ², B. Sreenivas ¹, S. Das Sharma ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN
2 Jai Narayan Vyas University, Jodhpur - 342 00 1, IN

Abstract

Pb-Pb isochron age of carbonate rocks of the Jhamarkotra Formation of the Aravalli Supergroup from the Udaipur sector in Rajasthan has been measured for the first time as 1921±67 Ma (2σ). We consider this as a reset age, as it is indistinguishable from the earlier reported Rb-Sr isochron age of 1900±8O Ma for the Darwal Granite formed synkinematically with the Aravalli deformation. The depositional age of the Jhamarkotra carbonates could be 200-300 Ma older as suggested by the positive δ¹³C anomalies noted in these carbonate rocks.

Keywords

Pb-Pb Isochron Age, Carbonates, Aravalli Supergroup Rajasthan.

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