Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Prabal Rakshit ¹, A. K. Sinha ²

Affiliations
1 Geological Survey of India, Env-I. W.R. 15-16. Jhalana Dungri, Jaipur- 302 004, IN
2 Department of Geology, University of Rajasthan, Jaipur, IN

Abstract

The Neogene/Quaternary boundary is reported to be erosional. The Pleistocene miliolite limestone shows the development of a sequence of palaeo-beach-dune complexes with the gradual fall of sea level. The late Pleistocene-Holocene stratigraphic units comprise different generations of deltaic sediments aggrading older tidal marshes and backswarnps. The late Holocene sea-level fall helped in delta progradation and the development of different accretionary units all along the coast.

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Prabal Rakshit ¹, Raghavan Minakshi Sundaram ²

Affiliations
1 Geological Survey of India, Jaipur, IN
2 Geological Survey of India, Hyderabad, IN

Abstract

Calcrete and gypsum crusts in Churu-Bikaner areas of the Thar desert, are presently found buried under a cover of aeolian sediments. Non-pedogenic and pedogenic calcrete types occur in various geomorphic locales like, channels, flood plains, pediments etc. Also, different non-pedogenic channel and lacustrine basin-fill gypsum crusts are noted. The occurrences of surface and near surface calcrete, gypsum crusts, their presence in representative sub-surface sequences of fluvio-aeolian sediments indicate climatic vicissitudes in the Late Quaternary from humid to arid and vice versa.

Keywords

Geomorphology, Weathering Crusts, Palaeoclimate, Calcrete, Thar Desert, Rajasthan.

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