Late Cretaceous-Early Paleogene (Turonian? to early Danian) planktic foraminifera from DSDP site 356: a biostratigraphic reappraisal

Abstract

Biostratigraphic results obtained with a systematic study of the planktic foraminiferal assemblages recovered from Upper Cretaceous-Lower Paleogene strata (Turonian? to early Danian in age) of Deep Sea Drilling Program (DSDP) Site 356, Sao Paulo Plateau, are presented and discussed herein. Fifty-nine planktic foraminiferal species were identifi ed within the studied interval, enabling the identifi cation of 11 planktic foraminiferal zones (Turonian? to early Danian in age): Marginotruncana schneegansi, Dicarinella concavata, Dicarinella asymetrica, Globotruncanita elevata, Contusotruncana plummerae, Radotruncana calcarata, Globotruncanella havanensis, Pseudoguembelina palpebra, Abathomphalus mayaroensis, Pseudoguembelina hariaensis and Pα. An unconformity spanning at least 0.96 Ma could also be suggested within core 31 (Maastrichtian in age), due to the absence of the Racemiguembelina fructicosa Interval Zone from the studied section. High sedimentation rates were estimated within the Santonian (Dicarinella asymentrica Total-range Zone) and the uppermost Maastrichtian (Pseudoguembelina hariaensis Interval Zone) of DSDP site 356, while lower and more constant values were suggested for the Campanian-lower Maastrichtian interval (Globotruncanita elevata Partial-range Zone to Pseudoguembelina palpebra Interval Zone). The reliability in identifying the Contusotruncana plummerae Interval Zone (Campanian in age) in Cretaceous sections of the South Atlantic Ocean is confi rmed herein.