Sedimentology and stable isotope ratios of planktonic foraminifera from two cores off Northeastern Brazil

• Main Authors: Arz, Helge Wolfgang, Pätzold, Jürgen, Wefer, Gerold
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 1998
• Subjects: GeoB3104-1; GeoB3912-1; Gravity corer (Kiel type); JOPSII-6; M34/4; Meteor (1986); NE-Brazilian continental margin; Northeast Brasilian Margin; SFB261; SL; South Atlantic in Late Quaternary: Reconstruction of Budget and Currents; Victor Hensen; Greenland; Greenland ice cores; North Atlantic; Planktonic foraminifera
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.711735; https://doi.org/10.1594/PANGAEA.711735

The stable isotope composition of planktonic foraminifera correlates with evidence for pulses of terrigenous sediment in a sediment core from the upper continental slope off northeastern Brazil. Stable oxygen isotope records of the planktonic foraminiferal species Globigerinoides sacculifer and Globigerinoides ruber (pink) reveal sub-Milankovitch changes in sea-surface hydrography during the last 85,000 yr. Warming of the surface water coincided with terrigenous sedimentation pulses that are inferred from high XRF intensities of Ti and Fe, and which suggest humid conditions in northeast Brazil. These tropical signals correlate with climatic oscillations recorded in Greenland ice cores (Dansgaard-Oeschger cycles) and in sediment cores from the North Atlantic (Heinrich events). Trade winds may have caused changes in the North Brazil Current that altered heat and salt flux into the North Atlantic, thus affecting the growth and decay of the large glacial ice sheets.