Paleoceanographic changes through the last 130 ka in the western South Atlantic based on planktonic Foraminifera

Abstract

This work reconstructs Late Quaternary paleoceanographic changes in the western South Atlantic Ocean based on sedimentary core GL-77, recovered from the lower continental slope in the Campos basin, off shore SE Brazil. The studied interval comprises the last 130 ka. Changes in sea surface temperature (SST) and paleoproductivity were estimated using the total planktonic foraminiferal fauna and oxygen isotope analyses. The age model was based on the oxygen isotope record, biostratigraphic datums and AMS 14C dating. It was observed that the Pleistocene/Holocene transition occurs within Globorotalia menardii Biozone Y, and is not coeval with the base of Biozone Z. The range between summer and winter SST estimates is larger during the glacial period compared to interglacials. Three peaks of low SST around 70, 50-45 and 20 ka coincided with periods of enhanced SE trade winds. Despite faunal diff erences between the last interglacial (MIS 5e) and the Holocene, our SST estimates suggest that SSTs did not diff er signifi cantly between these intervals.