Thursday, 30 August 2007 - 1:50 PM
4.P1.C-2
Pan-African age of the Gamburtsev Mountains?
Tina Van de Flierdt1, George E. Gehrels2, Steven L. Goldstein1, and Sidney R. Hemming1. (1) Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Columbia University, 61 Route 9W, Palisades, NY 10964, (2) Department of Geosciences, University of Arizona, Gould-Simpson building, 1040 E 4th St., Tucson, AZ 85721
We present new data on downcore sediments from ODP Site 1166 (Prydz Bay), taken in order to identify the age of the crust that makes up the subglacial Gamburtsev Mountains. Combined U-Pb dating of zircons, 40Ar/39Ar dating of hornblendes, and bulk Nd isotopic compositions reveal no major provenance change from pre-glacial erosional deposits (alluvial and deltaic sands) to glacial deposits (diamicts). Assuming that the alluvial and deltaic samples at Site 1166 with Eocene depositional ages comprise a significant fraction of material eroded from the Gamburtsev Mountains, the predominant pan-African population in U-Pb dated zircons indicates an age of ~500 Ma for the crust that makes up the Gamburtsev Mountains. Potential tectonic scenarios for a pan-African origin and the uplift history of the Gamburtsev Mountains, taking into account the remarkable present-day elevation, remain to be identified.
See more of Evolution of antarctic lithosphere ORAL
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See more of The 10th International Symposium on Antarctic Earth Sciences (Aug. 26 to Sept 1, 2007)
See more of General Submissions
See more of The 10th International Symposium on Antarctic Earth Sciences (Aug. 26 to Sept 1, 2007)