DSDP Site 534: Blake-Bahama Basin.

Abstract

Continuous coring between 536 and 1666.5m below the seafloor yielded a detailed ocean-basement and overlying sedimentary record spanning over 140 my of Atlantic Ocean history. Callovian through Albian, Cenomanian, Maestrichtian, late Eocene, and early Miocene sediments were recovered. The younger, unsampled section can be extrapolated from the findings at Site 391. The sedimentary sequence reflects largely continuous, quiescent 0.1 cm/103yr, or less hemipelagic sedimentation mostly between the calcium carbonate compensation depth for foraminifers and nannofossils. On this is superimposed periodic and much more rapid sedimentation by turbidite, debris flows, or deep currents of slope and shelf carbonates and carbonaceous claystone. Three-quarters of this sediment (decompacted thickness) was deposited in the first 50 m.y. after the site appeared on the mid-ocean ridge. Most of the overlying younger sediment was deposited in the Neogene.-from Authors