The Sambhar Lake: The Largest Saline Lake in Northwestern India

Abstract

The Sambhar Lake is a playa (seasonal lake with a flat bottom) located at the eastern fringe of the Thar Desert in Rajasthan. For more than four decades, this lake has attracted enormous attention due to its hypersalinity. The hypotheses to explain the geological evolution of the Sambhar have ranged from marine connection, river blockage by dunes and tectonics. This chapter presents the current understanding of the evolution of the Sambhar based on modern tools such as remote sensing and GIS and geochemical data such as evaporite mineralogy, elemental chemistry and stable isotopes. Available data suggest that the Sambhar Lake basin evolved as a pull-apart (extensional) basin and was further extended by geomorphic processes such as deflation. The hypersalinity of the Sambhar brine is related to progressive evaporation of fresh water in a semi-arid climate and the necessary chemical inputs for a hypersaline brine are derived from the catchment rocks. However, the salinity of the Sambhar Lake water has changed over time in response to variations in hydrological flux induced by climate change. Evaporite mineralogy and chemical composition of Sambhar Lake sediments have been used for reconstructing palaeoclimatic fluctuations in Thar region for the last 30,000 years.