HR: 09:15h
AN: PP41F-06    [Abstracts]
TI: High resolution record of glacial retreat in an Antarctic fjord, Maxwell Bay, South Shetland Islands
AU: * Milliken, K T
EM: milliken@rice.edu
AF: Rice University, Earth Sciences, Houston, TX 77005,
AU: Anderson, J B
EM: johna@rice.edu
AF: Rice University, Earth Sciences, Houston, TX 77005,
AU: Wellner, J
EM: jwellner@uh.edu
AF: University of Houston, Geosciences, Houston, TX 77204,
AU: Manley, P
EM: manley@middlebury.edu
AF: Middlebury College, Geology, Middlebury, VT 05753,
AU: Bohaty, S
EM: sbohaty@es.ucsc.edu
AF: University of California - Santa Cruz, Earth and Planetary Sciences, Santa Cruz, CA 95064,
AU: Michalchuk, B
AF: Rice University, Earth Sciences, Houston, TX 77005,
AB: Core and seismic data integration in Maxwell Bay, South Shetland Islands documents a minimum age for glacial retreat from the outer fjord of 13100 ± 60 BP or 13860 ± 140 cal BP at 488 m sub-sea. Glacio-marine suspension deposits described as dark greenish gray silty mud with abundant diatoms and occasional very fine sand laminations comprise the majority of the 107.3 m (87% recovery) core. The outer min-basin is divided into10 litho-units and 7 distinct seismic units. The litho-units are defined by sedimentation rate variations, as well as magnetic susceptibility and bulk stable carbon and nitrogen isotope zonations. Sedimentation rates vary by two orders of magnitude from 3 mm/yr to ~ 100 mm/yr. The highest sedimentation corresponds to an interval in the core which contains abundant sand laminations and pebbly mud intervals and likely represents the melt-out phase or period of rapid glacial retreat ~8000 cal BP. Subsequent sedimentation rates range from 3 to 9 mm/yr and reflect continuous high-resolution sedimentation record. The period between approximately 5500 calBP to 2800 calBP, also known as the Mid-Holocene climatic optimum, is marked by higher than average productivity.
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1641 Sea level change (1222, 1225, 4556)
DE: 3022 Marine sediments: processes and transport
DE: 4207 Arctic and Antarctic oceanography (9310, 9315)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting