New latitude-based nannofossil zonations for the Campanian?Maastrichtian of the South Atlantic Ocean and their paleoceanographic implications

DO MONTE GUERRA, R.; KENDER, SEV; CONCHEYRO, A.,; FAUTH, GERSON; WISE, SHERWOOD

PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 452 p. 55 - 67

0031-0182

The global evolution of calcareous nannofossils during the Campanian?Maastrichtian interval is not fullyunderstood, and nannofossil zonations for the central and South Atlantic Ocean are yet to be constructed. Here,we test the applicability of previous calcareous nannofossil zonations developed for other ocean basins, forbiostratigraphy in the South Atlantic Ocean, and refine Campanian?Maastrichtian biostratigraphy in the region.We document calcareous nannofossil distributions at Deep Sea Drilling Project (DSDP) and Ocean DrillingProgram (ODP) sites from the high, mid and low latitudes in the South Atlantic Ocean (DSDP Sites 354, 356, 511, 525A, and 530A, and ODP Sites 690C; 700B; 661A, and 1258A). Combining nannofossil occurrences with magnetostratigraphic schemes previously constructed for some of the sites, we propose three new zonations tied to the globalmagnetostratigraphic chrons,with distinct bio-horizons selected at different latitudinal regions.In this studywe present detailed definitions of new South Atlantic Ocean Low-latitude (SAL), South AtlanticMidlatitude (SAM) and South Atlantic High-latitude (SAH) zonations.We identified significant diachronismof some species between latitudes throughout the Campanian and Maastrichtian. These species diachronism, mainly between zonalmarkers fromlowandmid latitudes during the Late Maastrichtian,was probably related to migration patterns due to fundamental paleoceanographic changes.