Site 356: Sao Paulo Plateau

Abstract

We cored sediments to a subbottom depth of 741 meters on the southern edge of the Sào Paulo Plateau. The oldest sediments recovered are Albian laminated dolomitic limestones, which were deposited at intermediate depth (~1,000 m). These are overlain by Turonian-Coniacian conglomerates and mudstones, rich in organic matter, which were laid down in part at least, in a semirestricted basin of local or regional extent. Post- Coniacian sediments are mostly pelagic biogenic carbonates with varying admixtures of terrigenous material, and were deposited in an open marine basin. The carbonate section is continuous across the Cretaceous- Tertiary boundary; a thick Danian section was recovered. Siliceous components are present in significant quantities only in the Eocene. There is a hiatus at the Paleocene- Eocene boundary, an important hiatus from middle Eocene to lower Miocene, and a hiatus from lower Miocene to Pliocene.