Proxies of the East Antarctic shield: Composition and age of ice-covered basement from sedimentary and glacial provenance
Summary The Precambrian East Antarctic shield is the last geological frontier on the planet. Because of its thick ice-sheet cover, very limited exposure, continental scale and extreme challenge in obtaining sub-ice samples, little is known about the composition and structure of its interior. A poten...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.486.5100 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea132.pdf |
| Summary: | Summary The Precambrian East Antarctic shield is the last geological frontier on the planet. Because of its thick ice-sheet cover, very limited exposure, continental scale and extreme challenge in obtaining sub-ice samples, little is known about the composition and structure of its interior. A potentially rich body of information can be obtained, however, from sedimentary and glacial deposits found along the shield margin. Here I discuss several approaches to using such sedimentary and glacial proxies from two sections of the East Antarctic shield adjacent to the central Transantarctic Mountains and the Wilkes Land margin near Terre Adélie. In each area, transported rock clasts and sediment can be used for petrographic study, geochemical analysis, clast geochronology and detrital-zircon geochronology. Together, integration of data from petrologically-distinctive individual clasts and large detrital zircon populations provides a good first-order representation of the hidden East Antarctic shield terrains underlying different sections of the ice sheet. |
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