Clay Mineral Composition of Glacial Erratics, McMurdo Sound
Twenty-two erratics collected from coastal moraines along the shores of Mount Discovery, Brown Peninsula, Minna Bluff, on Black Island, and from the Salmon and Miers valley floors in East Antarctica were examined for their mineral composition in the <2 m fraction by x-ray diffraction to determine...
Main Author: | |
---|---|
Format: | Text |
Language: | unknown |
Published: |
DigitalCommons@University of Nebraska - Lincoln
2000
|
Subjects: | |
Online Access: | https://digitalcommons.unl.edu/geosciencefacpub/79 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1078/viewcontent/Holmes_PBPEERMSEA_2000_Clay_Mineral.pdf |
id |
ftunivnebraskali:oai:digitalcommons.unl.edu:geosciencefacpub-1078 |
---|---|
record_format |
openpolar |
spelling |
ftunivnebraskali:oai:digitalcommons.unl.edu:geosciencefacpub-1078 2023-11-12T04:06:50+01:00 Clay Mineral Composition of Glacial Erratics, McMurdo Sound Holmes, Mary Anne 2000-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/geosciencefacpub/79 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1078/viewcontent/Holmes_PBPEERMSEA_2000_Clay_Mineral.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/geosciencefacpub/79 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1078/viewcontent/Holmes_PBPEERMSEA_2000_Clay_Mineral.pdf Papers in the Earth and Atmospheric Sciences Earth Sciences text 2000 ftunivnebraskali 2023-10-30T10:32:43Z Twenty-two erratics collected from coastal moraines along the shores of Mount Discovery, Brown Peninsula, Minna Bluff, on Black Island, and from the Salmon and Miers valley floors in East Antarctica were examined for their mineral composition in the <2 m fraction by x-ray diffraction to determine their provenance and the climate under which the sediment in the erratics formed. Semi-quantitative results from peak areas were subjected to principal components analysis and indicate that there are two distinct mineral compositions in the erratics (C = 0.05): A) dominant smectite group minerals, minor illite and kaolinite, and no chlorite, and B) dominant illite, subordinate smectite group, and either chlorite and R=l US clay or R=3 US clay. Group A erratics include two types: 1) Eocene age siliciclastic sediment and 2) volcaniclastics of unknown age. Group B erratics comprise three types: 1) Eocene age siliciclastic sediment dominated by illite with subordinate smectite, no chlorite, and very low levels of kaolinite and mixed-layer clays; 2) post Eocene age erratics dominated by illite with a major component of chlorite and R=l US clay, minor or no smectite and kaolinite; and 3) post Eocene age erratics dominated by illite and containing R=3 US clay. Eocene age sediment occurs in either group and so had two distinct provenances for the clay fraction: a smectite-dominant area and an illite-rich, smectite-poor area. Post Eocene age sediment also had two distinct provenances for the clay fraction and are different from the Eocene sources: a metamorphic + ancient sedimentary terrain that supplied chlorite, illite, and R=l US clay to some of the erratics, and a sedimentary terrain that supplied illite and R=3 US clay. Kaolinite levels are low, indicating the absence of intense weathering and/or any significant contribution from the Beacon Supergroup. Text Antarc* Antarctica East Antarctica McMurdo Sound Black Island University of Nebraska-Lincoln: DigitalCommons@UNL East Antarctica McMurdo Sound Miers ENVELOPE(163.850,163.850,-78.100,-78.100) Miers Valley ENVELOPE(164.200,164.200,-78.100,-78.100) Minna Bluff ENVELOPE(166.417,166.417,-78.517,-78.517) Mount Discovery ENVELOPE(-59.716,-59.716,-62.483,-62.483) Brown Peninsula ENVELOPE(165.417,165.417,-78.100,-78.100) Black Island ENVELOPE(70.100,70.100,-49.440,-49.440) |
institution |
Open Polar |
collection |
University of Nebraska-Lincoln: DigitalCommons@UNL |
op_collection_id |
ftunivnebraskali |
language |
unknown |
topic |
Earth Sciences |
spellingShingle |
Earth Sciences Holmes, Mary Anne Clay Mineral Composition of Glacial Erratics, McMurdo Sound |
topic_facet |
Earth Sciences |
description |
Twenty-two erratics collected from coastal moraines along the shores of Mount Discovery, Brown Peninsula, Minna Bluff, on Black Island, and from the Salmon and Miers valley floors in East Antarctica were examined for their mineral composition in the <2 m fraction by x-ray diffraction to determine their provenance and the climate under which the sediment in the erratics formed. Semi-quantitative results from peak areas were subjected to principal components analysis and indicate that there are two distinct mineral compositions in the erratics (C = 0.05): A) dominant smectite group minerals, minor illite and kaolinite, and no chlorite, and B) dominant illite, subordinate smectite group, and either chlorite and R=l US clay or R=3 US clay. Group A erratics include two types: 1) Eocene age siliciclastic sediment and 2) volcaniclastics of unknown age. Group B erratics comprise three types: 1) Eocene age siliciclastic sediment dominated by illite with subordinate smectite, no chlorite, and very low levels of kaolinite and mixed-layer clays; 2) post Eocene age erratics dominated by illite with a major component of chlorite and R=l US clay, minor or no smectite and kaolinite; and 3) post Eocene age erratics dominated by illite and containing R=3 US clay. Eocene age sediment occurs in either group and so had two distinct provenances for the clay fraction: a smectite-dominant area and an illite-rich, smectite-poor area. Post Eocene age sediment also had two distinct provenances for the clay fraction and are different from the Eocene sources: a metamorphic + ancient sedimentary terrain that supplied chlorite, illite, and R=l US clay to some of the erratics, and a sedimentary terrain that supplied illite and R=3 US clay. Kaolinite levels are low, indicating the absence of intense weathering and/or any significant contribution from the Beacon Supergroup. |
format |
Text |
author |
Holmes, Mary Anne |
author_facet |
Holmes, Mary Anne |
author_sort |
Holmes, Mary Anne |
title |
Clay Mineral Composition of Glacial Erratics, McMurdo Sound |
title_short |
Clay Mineral Composition of Glacial Erratics, McMurdo Sound |
title_full |
Clay Mineral Composition of Glacial Erratics, McMurdo Sound |
title_fullStr |
Clay Mineral Composition of Glacial Erratics, McMurdo Sound |
title_full_unstemmed |
Clay Mineral Composition of Glacial Erratics, McMurdo Sound |
title_sort |
clay mineral composition of glacial erratics, mcmurdo sound |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2000 |
url |
https://digitalcommons.unl.edu/geosciencefacpub/79 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1078/viewcontent/Holmes_PBPEERMSEA_2000_Clay_Mineral.pdf |
long_lat |
ENVELOPE(163.850,163.850,-78.100,-78.100) ENVELOPE(164.200,164.200,-78.100,-78.100) ENVELOPE(166.417,166.417,-78.517,-78.517) ENVELOPE(-59.716,-59.716,-62.483,-62.483) ENVELOPE(165.417,165.417,-78.100,-78.100) ENVELOPE(70.100,70.100,-49.440,-49.440) |
geographic |
East Antarctica McMurdo Sound Miers Miers Valley Minna Bluff Mount Discovery Brown Peninsula Black Island |
geographic_facet |
East Antarctica McMurdo Sound Miers Miers Valley Minna Bluff Mount Discovery Brown Peninsula Black Island |
genre |
Antarc* Antarctica East Antarctica McMurdo Sound Black Island |
genre_facet |
Antarc* Antarctica East Antarctica McMurdo Sound Black Island |
op_source |
Papers in the Earth and Atmospheric Sciences |
op_relation |
https://digitalcommons.unl.edu/geosciencefacpub/79 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1078/viewcontent/Holmes_PBPEERMSEA_2000_Clay_Mineral.pdf |
_version_ |
1782327788614713344 |