QUATERNARY FACIES AND PALEOENVIRONMENT IN NORTH AND EAST OF SAMBHAR LAKE, RAJASTHAN

Quatemary landforms in the northern and eastern proximity of the Sambh ar lake in Rajasthan are products of depositional, structural and eros ional processes. The depositional landforms are made up of four fluvia l and two each lacustrine and aeolian facies. The structural and erosi onal landforms are carved out of Precambrian hard rocks. Each of the f our fluvial facies essentially comprises a sequence of upward fining s ediments characterised by a pedogenic cap except for the youngest one viz. laterocalcrete, calcrete and brown loamy soil. Amongst the two la custrine facies, the older is marked by the presence of saline deposit s and the younger by saliferous sediments. Of the two aeolian facies, the older is represented by longitudinal dunes, undulatory mounds and sandsheets while the younger by barchans and obstacle dunes. The depos itional facies have evolved in a sequence which indicate subtle variat ions in a predominantly arid climate. The presence of fluvial sediment s forming the lake base contradicts the earlier observation which sugg ested an aeolian base for these lacustrine sediments.