A History of Sediment Lithofacies in the South Atlantic Ocean

Abstract

Changes in sediment types (lithofacies) and sediment components (carbonate, foraminifers, calcareous nannoplankton) in the South Atlantic Ocean from Early Cretaceous through Pliocene are portrayed on a series of palinspastic maps which graphically document the sedimentological succession as this ocean basin evolves. Determination of paleolithofacies is based upon smear slide analyses of dated sediment from the base of over 300 piston cores and dredges which provides a broad regional coverage and supplements DSDP drilling data (with Leg 39 results as the primary data base). These maps graphically illustrate the development of oceanic circulation, CCD levels, terrigenous sediment influx, and biological productivity concomitant with changing sea-floor physiography, cycles of transgression and regression, and the Tertiary climatic deterioration.