Flood plain record of southwest Indian monsoon during the last glacial

Abstract

Rapid oscillations in the intensity of the Southwest Indian monsoon during the last glacial phase have been inferred for the first time, from newly generated continental records from the site of Bhimpura, located in the Mahi river flood plain in the tropical semi-arid parts of western India. The flood plain sediment belonging to the Last Glacial is characterized using grain size, degree of sorting, sediment facies, magnetic susceptibility, carbonate percentages (calcrete, CaCO3 and calcite), opaque magnetic heavy minerals, common rock forming minerals, and clay mineral percentages. Synthesizing these climate sensitive variables, seven flood periods and non-flood periods are identified. These episodes reflect strong and weak monsoonal phases at a time scale of a few thousand years.