Provenance of Glacially Transported Material near Nimrod Glacier, East Antarctica: Evidence of the Ice-Covered East Antarctic Shield
A Thesis submitted to the faculty of the Graduate School of the University of Minnesota by Devon Michele Brecke in partial fulfillment of the requirements for the degree of Master of Science, May 2007. Evaluation by glacial-clast petrography, igneous whole-rock geochemistry, metamorphic mineral comp...
Main Author: | |
---|---|
Format: | Thesis |
Language: | English |
Published: |
2007
|
Subjects: | |
Online Access: | http://hdl.handle.net/11299/212422 |
id |
ftunivminnesdc:oai:conservancy.umn.edu:11299/212422 |
---|---|
record_format |
openpolar |
spelling |
ftunivminnesdc:oai:conservancy.umn.edu:11299/212422 2023-05-15T13:37:39+02:00 Provenance of Glacially Transported Material near Nimrod Glacier, East Antarctica: Evidence of the Ice-Covered East Antarctic Shield Brecke, Devon Michele 2007-05 http://hdl.handle.net/11299/212422 en eng http://hdl.handle.net/11299/212422 Plan As (thesis-based master's degrees) Department of Earth and Environmental Sciences University of Minnesota Duluth UMD Master of Science Master of Science in Geological Sciences Thesis or Dissertation 2007 ftunivminnesdc 2022-07-21T06:57:59Z A Thesis submitted to the faculty of the Graduate School of the University of Minnesota by Devon Michele Brecke in partial fulfillment of the requirements for the degree of Master of Science, May 2007. Evaluation by 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 provide information on the composition of the ice-covered East Antarctic shield. Precambrian basement of East Antarctica is only documented in the Transantarctic Mountains near the polar plateau of Nimrod Glacier, providing an ideal location to look for adjacent sub-ice Precambrian terrain. Over 100 igneous and metamorphic rock clasts collected from moraines near the head of Nimrod Glacier show both local and transported material. Physical characteristics of local rock fall show angular edges, whereas distantly transported material exhibits rounded edges, glacial striations, or rock types only seen upstream. Most metamorphic rock types collected show intense deformation fabrics, high-grade mineral assemblages, and high-grade P-T conditions, which are similar to the Archean and Paleoproterozic 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). These samples are compared to Cambrian-Ordovician rocks in southern Victoria Land, which differ in trace element trends. 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. Thesis Antarc* Antarctic Antarctica East Antarctica Nimrod Glacier Victoria Land University of Minnesota Digital Conservancy Antarctic East Antarctica Granite Harbour ENVELOPE(162.733,162.733,-76.883,-76.883) Nimrod ENVELOPE(165.750,165.750,-85.417,-85.417) Nimrod Glacier ENVELOPE(163.000,163.000,-82.350,-82.350) Polar Plateau ENVELOPE(0.000,0.000,-90.000,-90.000) Transantarctic Mountains Victoria Land |
institution |
Open Polar |
collection |
University of Minnesota Digital Conservancy |
op_collection_id |
ftunivminnesdc |
language |
English |
topic |
Plan As (thesis-based master's degrees) Department of Earth and Environmental Sciences University of Minnesota Duluth UMD Master of Science Master of Science in Geological Sciences |
spellingShingle |
Plan As (thesis-based master's degrees) Department of Earth and Environmental Sciences University of Minnesota Duluth UMD Master of Science Master of Science in Geological Sciences Brecke, Devon Michele Provenance of Glacially Transported Material near Nimrod Glacier, East Antarctica: Evidence of the Ice-Covered East Antarctic Shield |
topic_facet |
Plan As (thesis-based master's degrees) Department of Earth and Environmental Sciences University of Minnesota Duluth UMD Master of Science Master of Science in Geological Sciences |
description |
A Thesis submitted to the faculty of the Graduate School of the University of Minnesota by Devon Michele Brecke in partial fulfillment of the requirements for the degree of Master of Science, May 2007. Evaluation by 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 provide information on the composition of the ice-covered East Antarctic shield. Precambrian basement of East Antarctica is only documented in the Transantarctic Mountains near the polar plateau of Nimrod Glacier, providing an ideal location to look for adjacent sub-ice Precambrian terrain. Over 100 igneous and metamorphic rock clasts collected from moraines near the head of Nimrod Glacier show both local and transported material. Physical characteristics of local rock fall show angular edges, whereas distantly transported material exhibits rounded edges, glacial striations, or rock types only seen upstream. Most metamorphic rock types collected show intense deformation fabrics, high-grade mineral assemblages, and high-grade P-T conditions, which are similar to the Archean and Paleoproterozic 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). These samples are compared to Cambrian-Ordovician rocks in southern Victoria Land, which differ in trace element trends. 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. |
format |
Thesis |
author |
Brecke, Devon Michele |
author_facet |
Brecke, Devon Michele |
author_sort |
Brecke, Devon Michele |
title |
Provenance of Glacially Transported Material near Nimrod Glacier, East Antarctica: Evidence of the Ice-Covered East Antarctic Shield |
title_short |
Provenance of Glacially Transported Material near Nimrod Glacier, East Antarctica: Evidence of the Ice-Covered East Antarctic Shield |
title_full |
Provenance of Glacially Transported Material near Nimrod Glacier, East Antarctica: Evidence of the Ice-Covered East Antarctic Shield |
title_fullStr |
Provenance of Glacially Transported Material near Nimrod Glacier, East Antarctica: Evidence of the Ice-Covered East Antarctic Shield |
title_full_unstemmed |
Provenance of Glacially Transported Material near Nimrod Glacier, East Antarctica: Evidence of the Ice-Covered East Antarctic Shield |
title_sort |
provenance of glacially transported material near nimrod glacier, east antarctica: evidence of the ice-covered east antarctic shield |
publishDate |
2007 |
url |
http://hdl.handle.net/11299/212422 |
long_lat |
ENVELOPE(162.733,162.733,-76.883,-76.883) ENVELOPE(165.750,165.750,-85.417,-85.417) ENVELOPE(163.000,163.000,-82.350,-82.350) ENVELOPE(0.000,0.000,-90.000,-90.000) |
geographic |
Antarctic East Antarctica Granite Harbour Nimrod Nimrod Glacier Polar Plateau Transantarctic Mountains Victoria Land |
geographic_facet |
Antarctic East Antarctica Granite Harbour Nimrod Nimrod Glacier Polar Plateau Transantarctic Mountains Victoria Land |
genre |
Antarc* Antarctic Antarctica East Antarctica Nimrod Glacier Victoria Land |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Nimrod Glacier Victoria Land |
op_relation |
http://hdl.handle.net/11299/212422 |
_version_ |
1766095657830973440 |