HR: 1400h
AN: PP43C-02    [Abstracts]
TI: Defining the Provenance Characteristics of Weddell Sea and Northeastern Antarctic Peninsula Sediment: A Multi-proxy Approach
AU: * Rosig, M J
EM: mollipop311@aol.com
AF: Department of Earth and Environmental Studies, Montclair State University, 1 Normal Avenue, Montclair, NJ 07043, United States
AU: Brachfeld, S
EM: brachfelds@mail.montclair.edu
AF: Department of Earth and Environmental Studies, Montclair State University, 1 Normal Avenue, Montclair, NJ 07043, United States
AU: Passchier, S
EM: passchiers@mail.montclair.edu
AF: Department of Earth and Environmental Studies, Montclair State University, 1 Normal Avenue, Montclair, NJ 07043, United States
AU: Gorring, M
EM: gorringm@mail.montclair.edu
AF: Department of Earth and Environmental Studies, Montclair State University, 1 Normal Avenue, Montclair, NJ 07043, United States
AB: The purpose of this study is to define the provenance characteristics of Weddell Sea and northeastern Antarctic Peninsula sediments, which will help identify past episodes of ice discharge from the Larsen and Ronne- Filchner Ice Shelf systems. Sampling targeted diamict where available; otherwise, sandy mud was collected. Samples were obtained from piston and phleger cores from the International Weddell Sea Oceanographic Expedition (IWSOE68, IWSOE69, IWSOE70), which were taken near the edge of the Ronne-Filchner ice shelf and along the west coast of Queen Maud Land. Jumbo piston cores and kasten cores from LMG05-02, NBP00-03, and NBP06-03 were collected from nearshore sites, in fjords, bays, and basins on the continental shelf. These sites were covered by the former Larsen-A and Larsen-B ice shelves until 1995 and 2002, respectively. The 500 μm-2mm grains were imbedded in epoxy for lithic fragment and mineral identification using optical microscopy. Preliminary observations in the Eastern Weddell Sea samples reveal the abundance of quartz, feldspars and sedimentary lithic fragments. Samples that were collected from the nearshore sites in the sub- Larsen area contain felsic intrusive lithic fragments, commonly in the form of quartz-rich granite. Microcline was present in a large portion of samples. Particle size analysis of samples from the edge of the Ronne-Filchner Ice Shelf showed a multi-modal distribution with no correlation to water depth. Samples were poorly sorted, suggesting contributions from ice-rafted debris. Particle size results from the Larsen-B Ice Shelf sites had very similar particle size distributions, displaying a weakly bimodal distribution with a large peak in the very fine to fine silt range and a smaller peak in the very coarse sand range. Work in progress includes major and trace element geochemical analysis of the <63 μm fraction, which will allow the study of fine-sediment distribution by ocean currents.
DE: 1051 Sedimentary geochemistry
DE: 3022 Marine sediments: processes and transport
DE: 9310 Antarctica (4207)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Joint Assembly