Amazon deep-sea fan

The Amazon River and the Amazon Fan (the deep-water sediment deposit formed on the continental margin by the Amazon River since the mid Miocene) have played an important role in preserving these climate records especially during low sea-level stands when the Amazon River discharged its sediment load directly into the deep sea. IDP Leg 155 will sample the sediment facies of the Amazon Fan in order to study its sedimentary response to Pleistocene sea level variations, evolution of Equatorial South American climate, and changes in western Equatorial Atlantic Ocean circulation. High-resolution seismic images of the Amazon Fan show that it has been built of a series of distinctive units that are typical of many mud-rich fans. The integrated analysis of fan architecture and growth pattern, land climate as recorded in fan sediments, and paleocirculation patterns in the western Equatorial Atlantic will allow us to understand more fully the response of this important equatorial region to glacial-interglacial and other cycles. -from Authors