Continuation of the Laurentian Grenville Province across the Ross Sea Margin of East Antarctica
Zircon U-Pb ages from glacial clasts in Quaternary tills of the central Transantarctic Mountains indicate the presence of Grenville-age crust along the Ross Sea margin of East Antarctica. The polymict tills contain a variety of igneous, metaigneous, and metasedimentary clasts with Proterozoic ages n...
Published in: | The Journal of Geology |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
University of Chicago Press
|
Subjects: | |
Online Access: | http://hdl.handle.net/1885/50609 https://doi.org/10.1086/656385 https://openresearch-repository.anu.edu.au/bitstream/1885/50609/5/u4027924xPUB207_2010.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/50609/7/01_Goodge_Continuation_of_the_Laurentian_2010.pdf.jpg |
id |
ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/50609 |
---|---|
record_format |
openpolar |
spelling |
ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/50609 2024-01-14T10:02:26+01:00 Continuation of the Laurentian Grenville Province across the Ross Sea Margin of East Antarctica Goodge, John W Fanning, Christopher Brecke, D.M. Licht, Kathy J. Palmer, Emerson F. http://hdl.handle.net/1885/50609 https://doi.org/10.1086/656385 https://openresearch-repository.anu.edu.au/bitstream/1885/50609/5/u4027924xPUB207_2010.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/50609/7/01_Goodge_Continuation_of_the_Laurentian_2010.pdf.jpg unknown University of Chicago Press 0022-1376 http://hdl.handle.net/1885/50609 doi:10.1086/656385 https://openresearch-repository.anu.edu.au/bitstream/1885/50609/5/u4027924xPUB207_2010.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/50609/7/01_Goodge_Continuation_of_the_Laurentian_2010.pdf.jpg Journal of Geology Keywords: basement rock craton glacial deposit granitoid Grenvillian orogeny ice sheet Laurentia Neogene orogeny Proterozoic Rodinia till uranium-lead dating zircon Antarctica Canada East Antarctica Grenville Province Ross Sea Southern Ocean Tra Journal article ftanucanberra https://doi.org/10.1086/656385 2023-12-15T09:33:33Z Zircon U-Pb ages from glacial clasts in Quaternary tills of the central Transantarctic Mountains indicate the presence of Grenville-age crust along the Ross Sea margin of East Antarctica. The polymict tills contain a variety of igneous, metaigneous, and metasedimentary clasts with Proterozoic ages not known from basement exposure. Four orthogneiss clasts have igneous ages of ∼1065-1100 Ma and Ross Orogen metamorphic overgrowths of ∼500-550 Ma. The latter ages indicate that these clasts are not glacially far traveled. Grenville-like signatures also come from a paragneiss containing detrital zircons ranging from 925 to 1130 Ma, an early Ross granitoid (∼563 Ma) containing inherited zircons of ∼1020 Ma, and detrital zircons from Neogene and Quaternary glacial deposits with a composite age peak of ∼1045 Ma. Other igneous clasts with ages of ∼1460, ∼1580, and ∼1880 Ma provide further evidence of Proterozoic crust and corroborate earlier finding of an ∼1440-Ma A-type granite clast with isotopic signatures matching similar-age granites in Laurentia. Together, the glacial clasts indicate that ∼1.1-Ga Grenville-age igneous crust lies beneath the ice sheet along the Ross Sea margin of East Antarctica. The clast ages are similar to those of Mesoproterozoic relicts in other parts of East Antarctica, and they resemble the ages of basement rocks in western Laurentia, including igneous rocks in west Texas (1070-1120 Ma) where the Grenville Orogen (sensu stricto) terminates abruptly, or, alternatively, metamorphic assemblages within Proterozoic rift-margin strata of northern Idaho (1000-1150 Ma). The glacial clasts provide new evidence that an ∼1.1-Ga-age belt extends from western Laurentia into central East Antarctica inboard of the present-day Pacific margin, supporting both the SWEAT (southwest U.S.-East Antarctic) fit of Rodinia cratons and the suggestion that a Mesoproterozoic orogen integral to Rodinia assembly crosses East Antarctica. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ross Sea Southern Ocean Australian National University: ANU Digital Collections Antarctic Southern Ocean East Antarctica Ross Sea Transantarctic Mountains Canada Pacific The Journal of Geology 118 6 601 619 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: basement rock craton glacial deposit granitoid Grenvillian orogeny ice sheet Laurentia Neogene orogeny Proterozoic Rodinia till uranium-lead dating zircon Antarctica Canada East Antarctica Grenville Province Ross Sea Southern Ocean Tra |
spellingShingle |
Keywords: basement rock craton glacial deposit granitoid Grenvillian orogeny ice sheet Laurentia Neogene orogeny Proterozoic Rodinia till uranium-lead dating zircon Antarctica Canada East Antarctica Grenville Province Ross Sea Southern Ocean Tra Goodge, John W Fanning, Christopher Brecke, D.M. Licht, Kathy J. Palmer, Emerson F. Continuation of the Laurentian Grenville Province across the Ross Sea Margin of East Antarctica |
topic_facet |
Keywords: basement rock craton glacial deposit granitoid Grenvillian orogeny ice sheet Laurentia Neogene orogeny Proterozoic Rodinia till uranium-lead dating zircon Antarctica Canada East Antarctica Grenville Province Ross Sea Southern Ocean Tra |
description |
Zircon U-Pb ages from glacial clasts in Quaternary tills of the central Transantarctic Mountains indicate the presence of Grenville-age crust along the Ross Sea margin of East Antarctica. The polymict tills contain a variety of igneous, metaigneous, and metasedimentary clasts with Proterozoic ages not known from basement exposure. Four orthogneiss clasts have igneous ages of ∼1065-1100 Ma and Ross Orogen metamorphic overgrowths of ∼500-550 Ma. The latter ages indicate that these clasts are not glacially far traveled. Grenville-like signatures also come from a paragneiss containing detrital zircons ranging from 925 to 1130 Ma, an early Ross granitoid (∼563 Ma) containing inherited zircons of ∼1020 Ma, and detrital zircons from Neogene and Quaternary glacial deposits with a composite age peak of ∼1045 Ma. Other igneous clasts with ages of ∼1460, ∼1580, and ∼1880 Ma provide further evidence of Proterozoic crust and corroborate earlier finding of an ∼1440-Ma A-type granite clast with isotopic signatures matching similar-age granites in Laurentia. Together, the glacial clasts indicate that ∼1.1-Ga Grenville-age igneous crust lies beneath the ice sheet along the Ross Sea margin of East Antarctica. The clast ages are similar to those of Mesoproterozoic relicts in other parts of East Antarctica, and they resemble the ages of basement rocks in western Laurentia, including igneous rocks in west Texas (1070-1120 Ma) where the Grenville Orogen (sensu stricto) terminates abruptly, or, alternatively, metamorphic assemblages within Proterozoic rift-margin strata of northern Idaho (1000-1150 Ma). The glacial clasts provide new evidence that an ∼1.1-Ga-age belt extends from western Laurentia into central East Antarctica inboard of the present-day Pacific margin, supporting both the SWEAT (southwest U.S.-East Antarctic) fit of Rodinia cratons and the suggestion that a Mesoproterozoic orogen integral to Rodinia assembly crosses East Antarctica. |
format |
Article in Journal/Newspaper |
author |
Goodge, John W Fanning, Christopher Brecke, D.M. Licht, Kathy J. Palmer, Emerson F. |
author_facet |
Goodge, John W Fanning, Christopher Brecke, D.M. Licht, Kathy J. Palmer, Emerson F. |
author_sort |
Goodge, John W |
title |
Continuation of the Laurentian Grenville Province across the Ross Sea Margin of East Antarctica |
title_short |
Continuation of the Laurentian Grenville Province across the Ross Sea Margin of East Antarctica |
title_full |
Continuation of the Laurentian Grenville Province across the Ross Sea Margin of East Antarctica |
title_fullStr |
Continuation of the Laurentian Grenville Province across the Ross Sea Margin of East Antarctica |
title_full_unstemmed |
Continuation of the Laurentian Grenville Province across the Ross Sea Margin of East Antarctica |
title_sort |
continuation of the laurentian grenville province across the ross sea margin of east antarctica |
publisher |
University of Chicago Press |
url |
http://hdl.handle.net/1885/50609 https://doi.org/10.1086/656385 https://openresearch-repository.anu.edu.au/bitstream/1885/50609/5/u4027924xPUB207_2010.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/50609/7/01_Goodge_Continuation_of_the_Laurentian_2010.pdf.jpg |
geographic |
Antarctic Southern Ocean East Antarctica Ross Sea Transantarctic Mountains Canada Pacific |
geographic_facet |
Antarctic Southern Ocean East Antarctica Ross Sea Transantarctic Mountains Canada Pacific |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ross Sea Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ross Sea Southern Ocean |
op_source |
Journal of Geology |
op_relation |
0022-1376 http://hdl.handle.net/1885/50609 doi:10.1086/656385 https://openresearch-repository.anu.edu.au/bitstream/1885/50609/5/u4027924xPUB207_2010.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/50609/7/01_Goodge_Continuation_of_the_Laurentian_2010.pdf.jpg |
op_doi |
https://doi.org/10.1086/656385 |
container_title |
The Journal of Geology |
container_volume |
118 |
container_issue |
6 |
container_start_page |
601 |
op_container_end_page |
619 |
_version_ |
1788057454765932544 |