Late Cambrian stratigraphy of the Heritage Range, Ellsworth Mountains: implications for basin evolution
Deposition of the Upper Cambrian succession of the Ellsworth Mountains was influenced by major, episodic tectonically-driven changes to the depositional basin geometry. We subdivide the succession into four stratigraphical sequences based on the recognition of three sequence-bounding unconformities....
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Online Access: | http://dx.doi.org/10.1017/s0954102099000103 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102099000103 |
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crcambridgeupr:10.1017/s0954102099000103 2024-09-15T17:49:05+00:00 Late Cambrian stratigraphy of the Heritage Range, Ellsworth Mountains: implications for basin evolution Curtis, Michael L. Lomas, Simon A. 1999 http://dx.doi.org/10.1017/s0954102099000103 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102099000103 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Antarctic Science volume 11, issue 1, page 63-77 ISSN 0954-1020 1365-2079 journal-article 1999 crcambridgeupr https://doi.org/10.1017/s0954102099000103 2024-07-31T04:03:44Z Deposition of the Upper Cambrian succession of the Ellsworth Mountains was influenced by major, episodic tectonically-driven changes to the depositional basin geometry. We subdivide the succession into four stratigraphical sequences based on the recognition of three sequence-bounding unconformities. The upper part of Sequence 1 is composed of the laterally equivalent Liberty Hills, Springer Peak and Frazier Ridge formations, a siliciclastic fluvial to marine deltaic association displaying NW-directed palaeocurrents. A switch in the position of the Late Cambrian depocentre from the north-west to the south coincided with cessation of terrigenous clastic deposition and accumulation of Sequence 2, the limestones of the Minaret Formation. Previously unreported talus breccias from the Independence Hills provide important clues to basin configuration at this time. A brief period of emergence of the Minaret Formation is inferred, prior to rapid subsidence and disconformable deposition of Sequence 3 (the ‘transition beds’) in outer-inner shelf environments. Localized intra-basinal uplift occurred prior to the deposition of Sequence 4 (the lower Crashsite Group), the base of which is locally an erosive unconformity, with a correlative conformity exposed elsewhere. We interpret the Upper Cambrian succession as representing the ‘rift-drift’ transition from initial rifting (preceded by Middle Cambrian volcanism) to thermal subsidence along the South African sector of the palaeo-Pacific margin of Gondwana. Article in Journal/Newspaper Antarctic Science Cambridge University Press Antarctic Science 11 1 63 77 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
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English |
description |
Deposition of the Upper Cambrian succession of the Ellsworth Mountains was influenced by major, episodic tectonically-driven changes to the depositional basin geometry. We subdivide the succession into four stratigraphical sequences based on the recognition of three sequence-bounding unconformities. The upper part of Sequence 1 is composed of the laterally equivalent Liberty Hills, Springer Peak and Frazier Ridge formations, a siliciclastic fluvial to marine deltaic association displaying NW-directed palaeocurrents. A switch in the position of the Late Cambrian depocentre from the north-west to the south coincided with cessation of terrigenous clastic deposition and accumulation of Sequence 2, the limestones of the Minaret Formation. Previously unreported talus breccias from the Independence Hills provide important clues to basin configuration at this time. A brief period of emergence of the Minaret Formation is inferred, prior to rapid subsidence and disconformable deposition of Sequence 3 (the ‘transition beds’) in outer-inner shelf environments. Localized intra-basinal uplift occurred prior to the deposition of Sequence 4 (the lower Crashsite Group), the base of which is locally an erosive unconformity, with a correlative conformity exposed elsewhere. We interpret the Upper Cambrian succession as representing the ‘rift-drift’ transition from initial rifting (preceded by Middle Cambrian volcanism) to thermal subsidence along the South African sector of the palaeo-Pacific margin of Gondwana. |
format |
Article in Journal/Newspaper |
author |
Curtis, Michael L. Lomas, Simon A. |
spellingShingle |
Curtis, Michael L. Lomas, Simon A. Late Cambrian stratigraphy of the Heritage Range, Ellsworth Mountains: implications for basin evolution |
author_facet |
Curtis, Michael L. Lomas, Simon A. |
author_sort |
Curtis, Michael L. |
title |
Late Cambrian stratigraphy of the Heritage Range, Ellsworth Mountains: implications for basin evolution |
title_short |
Late Cambrian stratigraphy of the Heritage Range, Ellsworth Mountains: implications for basin evolution |
title_full |
Late Cambrian stratigraphy of the Heritage Range, Ellsworth Mountains: implications for basin evolution |
title_fullStr |
Late Cambrian stratigraphy of the Heritage Range, Ellsworth Mountains: implications for basin evolution |
title_full_unstemmed |
Late Cambrian stratigraphy of the Heritage Range, Ellsworth Mountains: implications for basin evolution |
title_sort |
late cambrian stratigraphy of the heritage range, ellsworth mountains: implications for basin evolution |
publisher |
Cambridge University Press (CUP) |
publishDate |
1999 |
url |
http://dx.doi.org/10.1017/s0954102099000103 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102099000103 |
genre |
Antarctic Science |
genre_facet |
Antarctic Science |
op_source |
Antarctic Science volume 11, issue 1, page 63-77 ISSN 0954-1020 1365-2079 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0954102099000103 |
container_title |
Antarctic Science |
container_volume |
11 |
container_issue |
1 |
container_start_page |
63 |
op_container_end_page |
77 |
_version_ |
1810290794125328384 |