Diatom biostratigraphy of the Cenozoic glaciomarine Pagodroma Group, northern Prince Charles Mountains, East Antarctica
In the northern Prince Charles Mountains glaciomarine sediments of the Pagodroma Group outcrop on Fisher Massif (Mt Johnston and Fisher Bench Formations) and at the Amery Oasis (Battye Glacier and Bardin Bluffs Formations), at locations 300 and 250 km south of the Amery Ice Shelf edge, respectively....
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DigitalCommons@University of Nebraska - Lincoln
2004
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ftunivnebraskali:oai:digitalcommons.unl.edu:geosciencefacpub-1286 2023-11-12T04:00:41+01:00 Diatom biostratigraphy of the Cenozoic glaciomarine Pagodroma Group, northern Prince Charles Mountains, East Antarctica Whitehead, Jason M. Harwood, David M McKelvey, Barrie McMinn, Andrew 2004-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/geosciencefacpub/283 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1286/viewcontent/Harwood_AJES_2004_Diatom_stratigraphy__DC_VERSION.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/geosciencefacpub/283 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1286/viewcontent/Harwood_AJES_2004_Diatom_stratigraphy__DC_VERSION.pdf Papers in the Earth and Atmospheric Sciences Antarctic Ice Sheet Cenozoic diatoms Pagodroma Group Prince Charles Mountains Earth Sciences text 2004 ftunivnebraskali 2023-10-30T10:48:50Z In the northern Prince Charles Mountains glaciomarine sediments of the Pagodroma Group outcrop on Fisher Massif (Mt Johnston and Fisher Bench Formations) and at the Amery Oasis (Battye Glacier and Bardin Bluffs Formations), at locations 300 and 250 km south of the Amery Ice Shelf edge, respectively. Most of the Pagodroma Group consists of ice-proximal glaciomarine diamict, and a much subordinate (<2%) amount of more ice-distal mudstone. Microfossil biostratigraphy based upon in situ and glacially reworked diatoms constrains the ages of the four formations, and identifies at least six intervals of marine fjordal deposition. Sparse diatoms in Mt Johnston Formation diamicts indicate an Early Oligocene age. However, it is unclear whether these diatoms are in situ or else are glacially reworked and represent either an immediately prior or more remote past interglacial. The Battye Glacier and Fisher Bench Formations contain in situ diatoms and are broadly time equivalent, the former dating between 10.7 and 9.0 Ma and the latter between 12.1 or 10.7 Ma and 8.5 Ma. In situ diatoms indicate the Bardin Bluffs Formation to have been deposited between 2.6 and either 1.8 or 0.99 Ma. Glacially reworked diatoms in the Bardin Bluffs and Fisher Bench Formations identify four depositional intervals. The reworked taxa are sourced from Eocene– Oligocene (>30.1 Ma), Middle Miocene (14.5–12.5 Ma and 12.1–11.5 Ma), Early Pliocene (4.9–3.6 Ma) and, tentatively, Late Pliocene (3.4–2.6 Ma) strata. These microfossil data further develop the interpretation that the Pagodroma Group formed during episodes of reduced glacial extent when, in the absence of an ice shelf, marine waters penetrated far southwards into the Lambert Graben of East Antarctica. Text Amery Ice Shelf Antarc* Antarctic Antarctica Battye Glacier East Antarctica Ice Sheet Ice Shelf Prince Charles Mountains University of Nebraska-Lincoln: DigitalCommons@UNL Antarctic East Antarctica Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Amery Ice Shelf ENVELOPE(71.000,71.000,-69.750,-69.750) Prince Charles Mountains ENVELOPE(67.246,67.246,-71.427,-71.427) Battye Glacier ENVELOPE(67.900,67.900,-70.867,-70.867) Bardin Bluffs ENVELOPE(68.133,68.133,-70.819,-70.819) Fisher Massif ENVELOPE(67.667,67.667,-72.317,-72.317) |
institution |
Open Polar |
collection |
University of Nebraska-Lincoln: DigitalCommons@UNL |
op_collection_id |
ftunivnebraskali |
language |
unknown |
topic |
Antarctic Ice Sheet Cenozoic diatoms Pagodroma Group Prince Charles Mountains Earth Sciences |
spellingShingle |
Antarctic Ice Sheet Cenozoic diatoms Pagodroma Group Prince Charles Mountains Earth Sciences Whitehead, Jason M. Harwood, David M McKelvey, Barrie McMinn, Andrew Diatom biostratigraphy of the Cenozoic glaciomarine Pagodroma Group, northern Prince Charles Mountains, East Antarctica |
topic_facet |
Antarctic Ice Sheet Cenozoic diatoms Pagodroma Group Prince Charles Mountains Earth Sciences |
description |
In the northern Prince Charles Mountains glaciomarine sediments of the Pagodroma Group outcrop on Fisher Massif (Mt Johnston and Fisher Bench Formations) and at the Amery Oasis (Battye Glacier and Bardin Bluffs Formations), at locations 300 and 250 km south of the Amery Ice Shelf edge, respectively. Most of the Pagodroma Group consists of ice-proximal glaciomarine diamict, and a much subordinate (<2%) amount of more ice-distal mudstone. Microfossil biostratigraphy based upon in situ and glacially reworked diatoms constrains the ages of the four formations, and identifies at least six intervals of marine fjordal deposition. Sparse diatoms in Mt Johnston Formation diamicts indicate an Early Oligocene age. However, it is unclear whether these diatoms are in situ or else are glacially reworked and represent either an immediately prior or more remote past interglacial. The Battye Glacier and Fisher Bench Formations contain in situ diatoms and are broadly time equivalent, the former dating between 10.7 and 9.0 Ma and the latter between 12.1 or 10.7 Ma and 8.5 Ma. In situ diatoms indicate the Bardin Bluffs Formation to have been deposited between 2.6 and either 1.8 or 0.99 Ma. Glacially reworked diatoms in the Bardin Bluffs and Fisher Bench Formations identify four depositional intervals. The reworked taxa are sourced from Eocene– Oligocene (>30.1 Ma), Middle Miocene (14.5–12.5 Ma and 12.1–11.5 Ma), Early Pliocene (4.9–3.6 Ma) and, tentatively, Late Pliocene (3.4–2.6 Ma) strata. These microfossil data further develop the interpretation that the Pagodroma Group formed during episodes of reduced glacial extent when, in the absence of an ice shelf, marine waters penetrated far southwards into the Lambert Graben of East Antarctica. |
format |
Text |
author |
Whitehead, Jason M. Harwood, David M McKelvey, Barrie McMinn, Andrew |
author_facet |
Whitehead, Jason M. Harwood, David M McKelvey, Barrie McMinn, Andrew |
author_sort |
Whitehead, Jason M. |
title |
Diatom biostratigraphy of the Cenozoic glaciomarine Pagodroma Group, northern Prince Charles Mountains, East Antarctica |
title_short |
Diatom biostratigraphy of the Cenozoic glaciomarine Pagodroma Group, northern Prince Charles Mountains, East Antarctica |
title_full |
Diatom biostratigraphy of the Cenozoic glaciomarine Pagodroma Group, northern Prince Charles Mountains, East Antarctica |
title_fullStr |
Diatom biostratigraphy of the Cenozoic glaciomarine Pagodroma Group, northern Prince Charles Mountains, East Antarctica |
title_full_unstemmed |
Diatom biostratigraphy of the Cenozoic glaciomarine Pagodroma Group, northern Prince Charles Mountains, East Antarctica |
title_sort |
diatom biostratigraphy of the cenozoic glaciomarine pagodroma group, northern prince charles mountains, east antarctica |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2004 |
url |
https://digitalcommons.unl.edu/geosciencefacpub/283 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1286/viewcontent/Harwood_AJES_2004_Diatom_stratigraphy__DC_VERSION.pdf |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) ENVELOPE(71.000,71.000,-69.750,-69.750) ENVELOPE(67.246,67.246,-71.427,-71.427) ENVELOPE(67.900,67.900,-70.867,-70.867) ENVELOPE(68.133,68.133,-70.819,-70.819) ENVELOPE(67.667,67.667,-72.317,-72.317) |
geographic |
Antarctic East Antarctica Amery Amery Ice Shelf Prince Charles Mountains Battye Glacier Bardin Bluffs Fisher Massif |
geographic_facet |
Antarctic East Antarctica Amery Amery Ice Shelf Prince Charles Mountains Battye Glacier Bardin Bluffs Fisher Massif |
genre |
Amery Ice Shelf Antarc* Antarctic Antarctica Battye Glacier East Antarctica Ice Sheet Ice Shelf Prince Charles Mountains |
genre_facet |
Amery Ice Shelf Antarc* Antarctic Antarctica Battye Glacier East Antarctica Ice Sheet Ice Shelf Prince Charles Mountains |
op_source |
Papers in the Earth and Atmospheric Sciences |
op_relation |
https://digitalcommons.unl.edu/geosciencefacpub/283 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1286/viewcontent/Harwood_AJES_2004_Diatom_stratigraphy__DC_VERSION.pdf |
_version_ |
1782328478766465024 |