Quaternary Facies and Palaeoenvironment in North and East of Sambhar Lake, Rajasthan

Quaternary landforms in the northern and eastern proximity of the Sambhar lake in Rajasthan are products of depositional, structural and erosional processes. The depositional landforms are made up of four fluvial and two each lacustrine and aeolian facies. The structural and erosional landforms are carved out of Precambrian hard rocks. Each of the four fluvial facies essentially comprises a sequence of upward fining sediments characterised by a pedogenic cap except for the youngest one viz. laterocalcrete, calcrete and brown loamy soil. Amongst the two lacustrine facies, the older is marked by the presence of saline deposits 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 depositional facies have evolved in a sequence which indicate subtle variations in a predominantly arid climate. The presence of fluvial sediments forming the lake base contradicts the earlier observation which suggested an aeolian base for these lacustrine sediments.