A petrologic study of Weddell Sea sediments: implications for provenance and glacial history
Knowledge of subglacial geology in Antarctica is restricted due to limited outcrop exposure. Investigations of terrestrially derived sediments deposited on the Antarctic continental margin have proved successful for gaining increased understanding of this ice-covered continent. Petrologic analyses c...
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ftriceuniv:oai:scholarship.rice.edu:1911/103936 2023-05-15T13:35:53+02:00 A petrologic study of Weddell Sea sediments: implications for provenance and glacial history Andrews, Barbara Ann Anderson, John B. Baker, Donald R.;Bally, Albert W. 1984 211 pp reformatted digital application/pdf https://hdl.handle.net/1911/103936 eng eng Andrews, Barbara Ann. "A petrologic study of Weddell Sea sediments: implications for provenance and glacial history." (1984) Master’s Thesis, Rice University. https://hdl.handle.net/1911/103936 . https://hdl.handle.net/1911/103936 RICE1562 Thesis Geol. 1984 Andrews Thesis Text 1984 ftriceuniv 2022-08-09T20:53:24Z Knowledge of subglacial geology in Antarctica is restricted due to limited outcrop exposure. Investigations of terrestrially derived sediments deposited on the Antarctic continental margin have proved successful for gaining increased understanding of this ice-covered continent. Petrologic analyses conducted on glacial, glacial marine, and sediment gravity flow deposits from the Weddell Sea continental margin provide important evidence concerning subglacial geology and glacial history of land areas contiguous to the Weddell Sea. Petrologic data validates identifications, originally based on sed imen to 1ogic criteria, of basal tills on the Weddell Sea continental shelf. The presence of basal tills indicates a major expansion and coincident grounding of the East or West Antarctic Ice Sheet to the shelf edge. Petrologic evidence suggests that glacial expansion in the area of study was chiefly that of the East Antarctic Ice Sheet. Basal tills and transitional glacial marine sediments form distinct petrologic provinces on the Weddell Sea shelf. Most province boundaries extend inland parallel to ii reconstructed ice paleoflow lines. Till lithologies are dominated by volcanics and quartzose sedimentary rocks, in contrast to metamorphic outcrops of the Weddell Sea region. Comminution does not effectively bias till composition. Till lithologies suggest that mountainous outcrops are not representative of subglacial geology and that sedimentary basins exist beneath the Antarctic Ice Sheet. Four provenance areas for the Weddell Sea basal tills are modeled; correlations between modeled provenance areas and till petrologic provinces are good. Ice-rafted lithologies are limited in number and do not show the expected varied assemblage of Antarctic rock types. Derivation from a limited source area or from lateral moraines is suggested. Sediment gravity flow deposits from the Weddell Sea continental slope and abyssal plain are compositionally very different. Intracanyon slope debris flows and turbidites, composed chiefly of ... Thesis Antarc* Antarctic Antarctica Ice Sheet Weddell Sea Rice University: Digital Scholarship Archive Antarctic East Antarctic Ice Sheet The Antarctic Weddell Weddell Sea West Antarctic Ice Sheet |
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Rice University: Digital Scholarship Archive |
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ftriceuniv |
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English |
description |
Knowledge of subglacial geology in Antarctica is restricted due to limited outcrop exposure. Investigations of terrestrially derived sediments deposited on the Antarctic continental margin have proved successful for gaining increased understanding of this ice-covered continent. Petrologic analyses conducted on glacial, glacial marine, and sediment gravity flow deposits from the Weddell Sea continental margin provide important evidence concerning subglacial geology and glacial history of land areas contiguous to the Weddell Sea. Petrologic data validates identifications, originally based on sed imen to 1ogic criteria, of basal tills on the Weddell Sea continental shelf. The presence of basal tills indicates a major expansion and coincident grounding of the East or West Antarctic Ice Sheet to the shelf edge. Petrologic evidence suggests that glacial expansion in the area of study was chiefly that of the East Antarctic Ice Sheet. Basal tills and transitional glacial marine sediments form distinct petrologic provinces on the Weddell Sea shelf. Most province boundaries extend inland parallel to ii reconstructed ice paleoflow lines. Till lithologies are dominated by volcanics and quartzose sedimentary rocks, in contrast to metamorphic outcrops of the Weddell Sea region. Comminution does not effectively bias till composition. Till lithologies suggest that mountainous outcrops are not representative of subglacial geology and that sedimentary basins exist beneath the Antarctic Ice Sheet. Four provenance areas for the Weddell Sea basal tills are modeled; correlations between modeled provenance areas and till petrologic provinces are good. Ice-rafted lithologies are limited in number and do not show the expected varied assemblage of Antarctic rock types. Derivation from a limited source area or from lateral moraines is suggested. Sediment gravity flow deposits from the Weddell Sea continental slope and abyssal plain are compositionally very different. Intracanyon slope debris flows and turbidites, composed chiefly of ... |
author2 |
Anderson, John B. Baker, Donald R.;Bally, Albert W. |
format |
Thesis |
author |
Andrews, Barbara Ann |
spellingShingle |
Andrews, Barbara Ann A petrologic study of Weddell Sea sediments: implications for provenance and glacial history |
author_facet |
Andrews, Barbara Ann |
author_sort |
Andrews, Barbara Ann |
title |
A petrologic study of Weddell Sea sediments: implications for provenance and glacial history |
title_short |
A petrologic study of Weddell Sea sediments: implications for provenance and glacial history |
title_full |
A petrologic study of Weddell Sea sediments: implications for provenance and glacial history |
title_fullStr |
A petrologic study of Weddell Sea sediments: implications for provenance and glacial history |
title_full_unstemmed |
A petrologic study of Weddell Sea sediments: implications for provenance and glacial history |
title_sort |
petrologic study of weddell sea sediments: implications for provenance and glacial history |
publishDate |
1984 |
url |
https://hdl.handle.net/1911/103936 |
geographic |
Antarctic East Antarctic Ice Sheet The Antarctic Weddell Weddell Sea West Antarctic Ice Sheet |
geographic_facet |
Antarctic East Antarctic Ice Sheet The Antarctic Weddell Weddell Sea West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica Ice Sheet Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Weddell Sea |
op_relation |
Andrews, Barbara Ann. "A petrologic study of Weddell Sea sediments: implications for provenance and glacial history." (1984) Master’s Thesis, Rice University. https://hdl.handle.net/1911/103936 . https://hdl.handle.net/1911/103936 RICE1562 Thesis Geol. 1984 Andrews |
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