Foraminiferal assemblage and stable isotopic change across the Cenomanian-Turonian boundary in the subtropical North Atlantic

Abstract

The Cenomanian/Turonian boundary interval (CTBI) at Site 1050 (30869N, 768149W) was investigated to char-acterize climatic and oceanographic changes during the Oceanic Anoxic Event that was associated with it (OAE 2). Because of unusually good foraminiferal preservation for sediments of this age, we have obtained an unaltered oxygen and carbon isotope profile and an accompanying record of planktic and benthic foraminifer abundance changes across the OAE 2 interval. Biostratigraphic, sedimentologic, and chemostratigraphic analyses indi-cate that more than 0.5 m.y. between the onset and tail end of OAE 2 are missing. This explains why organic-rich sediments are absent from the Site 1050 sequence and why the planktic and benthic carbon isotope shifts