Continuous Late Pleistocene Paleoclimate Record from the Southwest African Margin: A Multi-Proxy Approach

• Main Author: Shackford, Julia Keegan
• Format: Others
• Published: Digital Archive @ GSU 2005
• Subjects: Benguela; Clay mineralogy; MIS; Multi-proxy; Paleoclimate; Pleistocene; Productivity; South Africa; Upwelling; Geography; Geology
• Online Access: http://digitalarchive.gsu.edu/geosciences_theses/1; http://digitalarchive.gsu.edu/cgi/viewcontent.cgi?article=1000&context=geosciences_theses

Late Pleistocene sediments recovered from ODP Leg 175, Site 1085 are used to generate a high-resolution (500 yr) record of continental climate change in Southern Africa. The location of Site 1085, the SW African continental slope, provides a continuous hemipelagic section with a significant terrigenous component. Terrigenous sediments are transported via fluvial and/or eolian transport mechanisms with MIS 1 being dominated by eolian transport. Analyses, including grain-size, color reflectance, biogenic sediment geochemistry (%CaCO3, %TOC, and C/N), bulk sediment geochemistry, and clay mineralogy, are used to identify continental climate conditions in southern Africa. Analyses indicate glacial/interglacial variation. Median grain-size peaks are associated with changes in transport. Clay mineralogy indicates the presence of kaolinite, smectite, and illite in varying percentages. Smectite and illite dominate the clay mineral assemblages except during MIS 2. Maximum kaolinite was found during MIS 2 and is associated with poleward transport by the Angola Counter Current.