Late-Quaternary variations in clay minerals along the SW continental margin of India: Evidence of climatic variations

Abstract

Down-core variations in illite, chlorite, smectite and kaolinite (the major clays) in two sup(14)C-dated cores collected along the SW continental margin of India show that illite and chlorite have enhanced abundance during 20-17, 12.5, 11-9.5, and 5-4.8 ka B.P., whereas smectite accumulation is higher between 17 and 12.5, and after 9 ka B.P. The climate may have been predominantly arid at 17 (20-17), 12.5, 10.5 (11-9.5), and 4.8 ka B.P. The first three dates correspond to the last glacial maximum, Bolling-Allerod, and Younger Dryas events, respectively. The SW monsoon was variable between 17 and 15 ka B.P., and it was more stable and intense after the Younger Dryas until about 6 ka B.P.