Clay mineralogy of sediment cores from the South Atlantic and the Adjoining Southern Ocean

• Main Authors: Diekmann, Bernhard, Petschick, Rainer, Gingele, Franz, Fütterer, Dieter K, Abelmann, Andrea, Brathauer, Uta, Gersonde, Rainer, Mackensen, Andreas
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 1996
• Subjects: Agulhas Basin; ANT-II/4; ANT-IV/4; ANT-IX/4; ANT-VIII/3; Argentine Islands; Atlantic Ridge; AWI_Paleo; Giant box corer; GKG; Gravity corer (Kiel type); Meteor Rise; Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Polarstern; PS04; PS04/539; PS04/540; PS04/542; PS08; PS08/504; PS08/507; PS08/555; PS1225-1; PS1225-2; PS1226-1; PS1433-1; PS1435-1; PS1450-1; PS16; PS16/267; PS16/271; PS16/278; PS16/284; PS16/311; PS16/312; PS1751-7; PS1752-1; PS1754-1; PS1756-5; PS1768-8; PS1769-1; PS18; PS18/238; PS2082-1; Shona Ridge; SL; Antarctic; Southern Ocean; The Antarctic; Argentine; Antarc*; North Atlantic Deep Water; North Atlantic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.728694; https://doi.org/10.1594/PANGAEA.728694

In the South Atlantic and adjoining Southern Ocean the kaolinite/chlorite-ratio in Late Quaternary sediments are an alternative deep water proxy to benthic foraminiferal proxies and carbonate preservation indices that is even suitable in regions with poor carbonate preservation. This paper shows the relationship between modern abyssal circulation and the kaolinite/chloriteratio and presents reconstructions of deep and bottom water advection based on the kaolinite/chlorite proxy. We also discuss the limitations and future perspectives of the kaolinite/chlorite proxy. Latitudinal and water depth-related patterns of the kaolinite/chlorite-ratio in surface sediments correspond to the modern deep and bottom water mass distribution. Kaolinite originates from lowlatitudes and traces North Atlantic Deep Water (northern-source deep water) advection to the south. Chlorite from the southern high-latitudes is exported via northward advecting Antarctic Bottom Water and Circumpolar Deep Water (southern-source deep and bottom water). Deep-sea sedimentation in regions underlying the Antarctic Circumpolar Current was current-dominated throughout the Late Quaternary. Temporal variations of the kaolinite/chlorite-ratio in response to glacial-interglacial cycles reflect changing deep water mass configurations, suggesting a shallowing and northward retreat of northern-source deep water and accordingly wider expansion of southernsource deep and bottom water masses during glacial times relative to interglacial times. Submarine topography influenced the spatial and temporal patterns of deep water mass distribution.