Pleistocene climatic changes as deduced from a pollen analysis of Site 717 cores

Abstract

Studies of the pollen content of the upper 200m of the ODP site 717 core from the Bengal deep sea fan reveals a major climatic change occurred around the beginning of the middle Pleistocene. Before this time the climate was warm and SW monsoon dominated, afterwards the climate became cold (pollen evidence) and glaciers in the Himalayas increased sediment input with coarser material coming in from the rivers Ganges, Irrawaddy and Brahamputra. A large increase in Pinus pollen suggests a NE monsoon carrying palynomorphs from the foot of the Himalayas. Then mangrove pollen increases, suggesting a stronger North Equatorial Current as well as the river input, along with a change in the monsoon circulation of the area. -after Authors