Tectonic and climatic controls on a Mesozoic forearc basin succession, Alexander Island, Antarctica
The Cretaceous Fossil Bluff Group on Alexander Island, on the west side of the Antarctic Peninsula, contains a remarkably complete record of the evolution of a forearc basin. The latest (Aptian–Albian) stages in the basin history are recorded in a well-exposed succession at the southern end of the i...
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2002
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Online Access: | http://dx.doi.org/10.1017/s0016756802006465 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756802006465 |
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crcambridgeupr:10.1017/s0016756802006465 2024-09-15T17:36:32+00:00 Tectonic and climatic controls on a Mesozoic forearc basin succession, Alexander Island, Antarctica NICHOLS, GARY J. CANTRILL, DAVID J. 2002 http://dx.doi.org/10.1017/s0016756802006465 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756802006465 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 139, issue 3, page 313-330 ISSN 0016-7568 1469-5081 journal-article 2002 crcambridgeupr https://doi.org/10.1017/s0016756802006465 2024-07-31T04:04:38Z The Cretaceous Fossil Bluff Group on Alexander Island, on the west side of the Antarctic Peninsula, contains a remarkably complete record of the evolution of a forearc basin. The latest (Aptian–Albian) stages in the basin history are recorded in a well-exposed succession at the southern end of the island, where a series of nunataks provide exposure of over a thousand metres of shallow marine and continental deposits. An abrupt facies shift from upper shoreface marine facies to braided fluvial deposits is interpreted as the record of regional uplift in the volcanic arc. This event coincides with the Palmer Land deformation event which may be related to a mid-Cretaceous mantle plume. A gradual reduction in depositional gradient and a return to shallow marine conditions towards the top of the exposed section is interpreted as a consequence of erosion of the arc and subsidence within the basin. Palaeocurrent data and facies distributions indicate that the continental deposits formed a fan-shaped wedge at least 30 km in diameter in the southern part of the forearc basin. Fossil plants indicate that the palaeoclimate was warm and humid throughout the period of deposition. Mapping and facies analysis of the upper part of the Fossil Bluff Group in southern Alexander Island has resulted in a revision of the stratigraphic terminology for the area. The Triton Point Member, formerly part of the Neptune Glacier Formation, has been raised to formation status and two members (the Citadel Bastion Member and the Coal Nunatak Member) and a Bed (the Upper Coal Nunatak Sandstone Bed) are defined here within the formation. Article in Journal/Newspaper Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Neptune Glacier Palmer Land Cambridge University Press Geological Magazine 139 3 313 330 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
The Cretaceous Fossil Bluff Group on Alexander Island, on the west side of the Antarctic Peninsula, contains a remarkably complete record of the evolution of a forearc basin. The latest (Aptian–Albian) stages in the basin history are recorded in a well-exposed succession at the southern end of the island, where a series of nunataks provide exposure of over a thousand metres of shallow marine and continental deposits. An abrupt facies shift from upper shoreface marine facies to braided fluvial deposits is interpreted as the record of regional uplift in the volcanic arc. This event coincides with the Palmer Land deformation event which may be related to a mid-Cretaceous mantle plume. A gradual reduction in depositional gradient and a return to shallow marine conditions towards the top of the exposed section is interpreted as a consequence of erosion of the arc and subsidence within the basin. Palaeocurrent data and facies distributions indicate that the continental deposits formed a fan-shaped wedge at least 30 km in diameter in the southern part of the forearc basin. Fossil plants indicate that the palaeoclimate was warm and humid throughout the period of deposition. Mapping and facies analysis of the upper part of the Fossil Bluff Group in southern Alexander Island has resulted in a revision of the stratigraphic terminology for the area. The Triton Point Member, formerly part of the Neptune Glacier Formation, has been raised to formation status and two members (the Citadel Bastion Member and the Coal Nunatak Member) and a Bed (the Upper Coal Nunatak Sandstone Bed) are defined here within the formation. |
format |
Article in Journal/Newspaper |
author |
NICHOLS, GARY J. CANTRILL, DAVID J. |
spellingShingle |
NICHOLS, GARY J. CANTRILL, DAVID J. Tectonic and climatic controls on a Mesozoic forearc basin succession, Alexander Island, Antarctica |
author_facet |
NICHOLS, GARY J. CANTRILL, DAVID J. |
author_sort |
NICHOLS, GARY J. |
title |
Tectonic and climatic controls on a Mesozoic forearc basin succession, Alexander Island, Antarctica |
title_short |
Tectonic and climatic controls on a Mesozoic forearc basin succession, Alexander Island, Antarctica |
title_full |
Tectonic and climatic controls on a Mesozoic forearc basin succession, Alexander Island, Antarctica |
title_fullStr |
Tectonic and climatic controls on a Mesozoic forearc basin succession, Alexander Island, Antarctica |
title_full_unstemmed |
Tectonic and climatic controls on a Mesozoic forearc basin succession, Alexander Island, Antarctica |
title_sort |
tectonic and climatic controls on a mesozoic forearc basin succession, alexander island, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
2002 |
url |
http://dx.doi.org/10.1017/s0016756802006465 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756802006465 |
genre |
Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Neptune Glacier Palmer Land |
genre_facet |
Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Neptune Glacier Palmer Land |
op_source |
Geological Magazine volume 139, issue 3, page 313-330 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0016756802006465 |
container_title |
Geological Magazine |
container_volume |
139 |
container_issue |
3 |
container_start_page |
313 |
op_container_end_page |
330 |
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1810490075150024704 |