paleolake

A paleolake is a former lake, typically from a previous geological period. Paleohydrology, the science concerned with past hydrologic systems, infers these past conditions from evidence in rocks, such as alterations, depositions, and erosion.1

During the Pleistocene Epoch, large lakes, often much bigger than their modern counterparts, were common. These lakes, known as pluvial lakes, existed in areas that are now arid or semiarid. Their levels fluctuated due to climatic cycles, glaciation, and land movements. Sediments found at the bottom of lakes provide geologists with clues about the lake's history, the basin it occupied, and past climates. Playas, which are flat-bottomed depressions in desert basins, can also be the remnants of former lakes, with their salt and clay deposits reflecting periods of inundation and evaporation.234