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Article
Marine sediment record from the East Antarctic margin reveals dynamics of ice sheet recession
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
  • Amy Leventer, Colgate University
  • Eugene Domack, Hamilton College
  • Jennifer Pike, Cardiff University
  • Catherine Stickley, Cardiff University
  • Eleanor Maddison, Cardiff University
  • Stefanie A. Brachfeld, Montclair State University
  • Patricia Manley, Middlebury College
  • Charlie McClennen, Colgate University
Document Type
Article
Publication Date
12-1-2006
Disciplines
Abstract

The Antarctic shelf is traversed by large-scale troughs developed by glacial erosion. Swath bathymetric, lithologic, and chronologic data from jumbo piston cores from four sites along the East Antarctic margin (Iceberg Alley, the Nielsen Basin, the Svenner Channel, and the Mertz-Ninnis Trough) are used to demonstrate that these cross-shelf features controlled development of calving bay reentrants in the Antarctic ice sheet during deglaciation. At all sites except the Mertz-Ninnis Trough, the transition between the Last Glacial Maximum and the Holocene is characterized by varved couplets deposited during a short interval of extremely high primary productivity in a fjordlike setting. Nearly monospecific layers of the diatom Chaetoceros alternate with slightly more terrigenous layers containing a mixed diatom assemblage. We propose that springtime diatom blooms dominated by Chaetoceros were generated within well-stratified and restricted surface waters of calving bays that were influenced by the input of iron-rich meltwater. Intervening post-bloom summer-fall laminae were formed through the downward flux of terrigenous material sourced from melting glacial ice combined with mixed diatom assemblages. Radiocarbon-based chronologies that constrain the timing of deposition of the varved sediments within calving bay reentrants along the East Antarctic margin place deglaciation between ca. 10,500–11,500 cal yr B.P., post-dating Meltwater Pulse 1A (14,200 cal yr B.P.) and indicating that retreat of ice from the East Antarctic margin was not the major contributor to this pulse of meltwater.

DOI
10.1130/GSAT01612A.1
Published Citation
Leventer, A., Domack, E., Dunbar, R., Pike, J., Stickley, C., Maddison, E., . . . McClennen, C. (2006). Marine sediment record from the East Antarctic margin reveals dynamics of ice sheet recession. GSA TODAY, 16(12), 4.
Citation Information
Amy Leventer, Eugene Domack, Jennifer Pike, Catherine Stickley, et al.. "Marine sediment record from the East Antarctic margin reveals dynamics of ice sheet recession" (2006)
Available at: http://works.bepress.com/stefanie-brachfeld/11/