Provenance of glacially transported material near Nimrod Glacier, East Antarctica: Implications for the ice-covered East Antarctic shield
Summary Study of glacial-clast petrography, igneous whole-rock geochemistry, metamorphic mineral composition, and magnetic susceptibility of glacially eroded, transported, and deposited material near Nimrod Glacier, East Antarctica provides information on the composition of the ice-covered East Anta...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.524.6340 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea125.pdf |
| Summary: | Summary Study of glacial-clast petrography, igneous whole-rock geochemistry, metamorphic mineral composition, and magnetic susceptibility of glacially eroded, transported, and deposited material near Nimrod Glacier, East Antarctica provides information on the composition of the ice-covered East Antarctic shield. Over 100 igneous and metamorphic rocks collected from moraines near Nimrod Glacier show both local and transported material. Most metamorphic rocks collected show intense deformation fabrics, high-grade mineral assemblages, and high-grade P-T conditions, which are similar to the Archean and Paleoproterozoic Nimrod Group. Many igneous rocks may originate from either the Nimrod Group or from the syn-tectonic and post-tectonic Cambrian-Ordovician Granite Harbour Intrusive series, and some come from nearby Ferrar dolerite (Jurassic). Although many of the clasts can be explained by local derivation, others appear exotic and may represent more distal origins in the shield interior. Future geochronology will help to refine the relative contributions of local and distal sources to test these conclusions. |
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