Sheet (EAIS) and the West Antarctic Ice Sheet (WAIS), with the goal of fingerprinting the bedrock geology underlying the ice. Glacial-marine diamict and sandy mud recovered from inner-shelf basins and fjords were examined for lithic clast composition, bulk geochemistry of the < 63-micron fraction...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.522.4333 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea060.pdf |
| Summary: | Sheet (EAIS) and the West Antarctic Ice Sheet (WAIS), with the goal of fingerprinting the bedrock geology underlying the ice. Glacial-marine diamict and sandy mud recovered from inner-shelf basins and fjords were examined for lithic clast composition, bulk geochemistry of the < 63-micron fraction, 40Ar/39Ar ages of individual hornblende grains, and radioisotope signatures. Samples from the George V Coast have several distinctive characteristics, including abundant metamorphic lithic clasts, and high concentrations of Mn and Cr relative to Prydz Bay and Mac.Robertson Land, located further to the west. Mac.Robertson Land also displays high metamorphic content and high garnet content relative to Ross Sea tills (Licht et al., 2005). Samples from West Antarctica contain abundant felsic igneous clasts, sedimentary clasts, and monomineralic quartz and potassium feldspar. Al/Ti ratios and Fe/Ti ratios from East Antarctica range from 12-21 and 6-16, respectively. We speculate that the George V samples are iron rich due to the presence of ironstone in the source region. The George V Coast samples are Ti-poor and Al-poor relative to Prydz Bay, Svenner Channel, and Mac.Robertson Land. West Antarctic samples have lower Al/Ti ratios (7-17), and fairly constant Fe/Ti ratios between 7-10. The East Antarctic margin samples have strongly negative eNd values and old 40Ar/39Ar ages relative to West Antarctica. These characteristics may provide a means of |
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