2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 40-29
Presentation Time: 9:00 AM-5:30 PM


COFIELD, Shannon McMahon, Ocean, Earth, and Atmospheric Sciences, Old Dominion University, 340 Oceanography Physics Building (OCNPS), Norfolk, VA 23529, DARBY, Dennis A., Department of Ocean, Earth, & Atmospheric Sciences, Old Dominion University, Norfolk, VA 23529 and ST. JOHN, Kristen, Department of Geology and Environmental Science, James Madison University, Harrisonburg, VA 22807, scofi002@odu.edu

The Pleistocene history and location of the Laurentide and Fenno-Scandinavian Ice Sheets are well constrained, and to a lesser degree the Innuition, Greenland, and Barents Ice Sheets are also constrained. Other proposed Arctic ice masses and shelf ice remain speculative. The presence and thickness of large ice caps in the central Arctic during glacial maxima have been proposed, but lacks hard evidence (Jakobsson et al., 2001). Thick ice caps would prevent broad scale circulation of ice, thus restricting the transport of ice-rafted detritus (IRD). If IRD from East Siberian or Laptev Sea sources were identified in sediment cores from the Fram Strait during glacial maxima, it would suggest ice was able to circulate, and the Arctic Ocean was not covered by thick ice. The Fe-grain fingerprinting method of Darby et al. (2015) was utilized to identify the provenance of Fe oxides in well-dated sediment cores from Fram Strait for the last glacial maximum (Marine Isotope Stage 2; 14-29 ka). Preliminary results indicate IRD from the Laptev Sea and Wrangel Island were transported and deposited at the Fram Strait during the last glacial maximum, which may indicate the lack of a thick ice cap in the central Arctic Ocean. Further high-resolution analysis will help determine the presence of a proposed thick ice cap during glacial maxima up to MIS 6 (190 Ka).