Channel to the Strait : the geological history of the Tamar Valley–Launceston area
The Tamar Valley occupies the Tamar Graben, a geological structure defined by a series of parallel NW-trending faults which have lowered the dolerite basement to below sea level. The resulting narrow trough, some 50 km long and 5 km wide, has been partially infilled with soft sands, clays and gravel...
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ftunivtasmania:oai:eprints.utas.edu.au:36839 2023-05-15T13:41:50+02:00 Channel to the Strait : the geological history of the Tamar Valley–Launceston area Corbett, KD 2021 application/pdf https://eprints.utas.edu.au/36839/ https://eprints.utas.edu.au/36839/2/07%20-%20Papers%20and%20Proceedings%20-%20Volume%20155%20-%20Corbett.pdf en eng https://eprints.utas.edu.au/36839/2/07%20-%20Papers%20and%20Proceedings%20-%20Volume%20155%20-%20Corbett.pdf Corbett, KD 2021 , 'Channel to the Strait : the geological history of the Tamar Valley–Launceston area' , Papers and Proceedings of the Royal Society of Tasmania, vol. 155, no. 1 , pp. 51-62 , doi:10.26749/rstpp.155.1.51 <http://dx.doi.org/10.26749/rstpp.155.1.51>. cc_utas 210000 Science - General 260100 Geology Tasmanian geology Tamar Valley Tamar Graben Launceston geology Bass Basin Gondwana Article PeerReviewed 2021 ftunivtasmania https://doi.org/10.26749/rstpp.155.1.51 2022-02-14T23:17:33Z The Tamar Valley occupies the Tamar Graben, a geological structure defined by a series of parallel NW-trending faults which have lowered the dolerite basement to below sea level. The resulting narrow trough, some 50 km long and 5 km wide, has been partially infilled with soft sands, clays and gravels, with intercalated basalt flows in places, of mainly Paleogene (lower Tertiary) age. Low hills of hard Jurassic dolerite define the structure on either side. The graben was formed during the break-up of Gondwana, the separation of Australia from Antarctica, and the making of Tasmania, in the Cretaceous-early Cenozoic period, some 70–140 million years ago (Ma). A spreading ridge had propagated eastwards through the Great Australian Bight but was unable to break through the Bass Strait area, and instead a large wedge of crust containing the future Tasmania was pulled away from the corner of Antarctica on a series of transcurrent faults. The associated crustal stretching in the Bass Strait area resulted in the formation of the deep ‘hole’ of Bass Basin, which had offshoots onto what became Tasmania, including the Tamar Graben. For much of its life, the Tamar River was a major feeder stream into the Bass Basin, carrying large volumes of sediment eroded from the Tasmanian highlands. The course of its major tributary, the South Esk River, within the southern part of the graben was completely blocked by basalt flows near the present Evandale about 35 Ma, forcing it into a new course to the west through the dolerite, to form the Cataract Gorge. Article in Journal/Newspaper Antarc* Antarctica University of Tasmania: UTas ePrints Papers and Proceedings of The Royal Society of Tasmania 155 1 51 62 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
210000 Science - General 260100 Geology Tasmanian geology Tamar Valley Tamar Graben Launceston geology Bass Basin Gondwana |
spellingShingle |
210000 Science - General 260100 Geology Tasmanian geology Tamar Valley Tamar Graben Launceston geology Bass Basin Gondwana Corbett, KD Channel to the Strait : the geological history of the Tamar Valley–Launceston area |
topic_facet |
210000 Science - General 260100 Geology Tasmanian geology Tamar Valley Tamar Graben Launceston geology Bass Basin Gondwana |
description |
The Tamar Valley occupies the Tamar Graben, a geological structure defined by a series of parallel NW-trending faults which have lowered the dolerite basement to below sea level. The resulting narrow trough, some 50 km long and 5 km wide, has been partially infilled with soft sands, clays and gravels, with intercalated basalt flows in places, of mainly Paleogene (lower Tertiary) age. Low hills of hard Jurassic dolerite define the structure on either side. The graben was formed during the break-up of Gondwana, the separation of Australia from Antarctica, and the making of Tasmania, in the Cretaceous-early Cenozoic period, some 70–140 million years ago (Ma). A spreading ridge had propagated eastwards through the Great Australian Bight but was unable to break through the Bass Strait area, and instead a large wedge of crust containing the future Tasmania was pulled away from the corner of Antarctica on a series of transcurrent faults. The associated crustal stretching in the Bass Strait area resulted in the formation of the deep ‘hole’ of Bass Basin, which had offshoots onto what became Tasmania, including the Tamar Graben. For much of its life, the Tamar River was a major feeder stream into the Bass Basin, carrying large volumes of sediment eroded from the Tasmanian highlands. The course of its major tributary, the South Esk River, within the southern part of the graben was completely blocked by basalt flows near the present Evandale about 35 Ma, forcing it into a new course to the west through the dolerite, to form the Cataract Gorge. |
format |
Article in Journal/Newspaper |
author |
Corbett, KD |
author_facet |
Corbett, KD |
author_sort |
Corbett, KD |
title |
Channel to the Strait : the geological history of the Tamar Valley–Launceston area |
title_short |
Channel to the Strait : the geological history of the Tamar Valley–Launceston area |
title_full |
Channel to the Strait : the geological history of the Tamar Valley–Launceston area |
title_fullStr |
Channel to the Strait : the geological history of the Tamar Valley–Launceston area |
title_full_unstemmed |
Channel to the Strait : the geological history of the Tamar Valley–Launceston area |
title_sort |
channel to the strait : the geological history of the tamar valley–launceston area |
publishDate |
2021 |
url |
https://eprints.utas.edu.au/36839/ https://eprints.utas.edu.au/36839/2/07%20-%20Papers%20and%20Proceedings%20-%20Volume%20155%20-%20Corbett.pdf |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
https://eprints.utas.edu.au/36839/2/07%20-%20Papers%20and%20Proceedings%20-%20Volume%20155%20-%20Corbett.pdf Corbett, KD 2021 , 'Channel to the Strait : the geological history of the Tamar Valley–Launceston area' , Papers and Proceedings of the Royal Society of Tasmania, vol. 155, no. 1 , pp. 51-62 , doi:10.26749/rstpp.155.1.51 <http://dx.doi.org/10.26749/rstpp.155.1.51>. |
op_rights |
cc_utas |
op_doi |
https://doi.org/10.26749/rstpp.155.1.51 |
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Papers and Proceedings of The Royal Society of Tasmania |
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155 |
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1 |
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51 |
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