Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania
Cut-back of a sea-cliff at Hannant Inlet in remote South-West Tasmania has exposed Oligocene clays buried under Late Pleistocene “colluvium” from which abundant wood fragments protrude. The two units are separated by a transitional interval defined by mixed Oligocene and Pleistocene microfloras. Mic...
Published in: | Papers and Proceedings of the Royal Society of Tasmania |
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Online Access: | https://eprints.utas.edu.au/23202/ https://eprints.utas.edu.au/23202/7/04%20_McPhail.pdf |
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ftunivtasmania:oai:eprints.utas.edu.au:23202 2023-05-15T14:04:48+02:00 Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania Macphail, MK Sharples, C Bowman, DMJS Wood, SW Haberle, S 2014 application/pdf https://eprints.utas.edu.au/23202/ https://eprints.utas.edu.au/23202/7/04%20_McPhail.pdf en eng https://eprints.utas.edu.au/23202/7/04%20_McPhail.pdf Macphail, MK, Sharples, C, Bowman, DMJS, Wood, SW and Haberle, S 2014 , 'Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania' , Papers and Proceedings of the Royal Society of Tasmania, vol. 148 , pp. 43-59 , doi:10.26749/rstpp.148.43 <http://dx.doi.org/10.26749/rstpp.148.43>. cc_utas 210000 Science - General 260100 Geology Cenozoic palynostratigraphy Tasmania Antarctica South America Oligocene Pleistocene Lophosoria Embothrium Pherosphaera trans-oceanic migration The Royal Society of Tasmania natural history science papers & proceedings Australia Article PeerReviewed 2014 ftunivtasmania https://doi.org/10.26749/rstpp.148.43 2020-05-30T07:37:47Z Cut-back of a sea-cliff at Hannant Inlet in remote South-West Tasmania has exposed Oligocene clays buried under Late Pleistocene “colluvium” from which abundant wood fragments protrude. The two units are separated by a transitional interval defined by mixed Oligocene and Pleistocene microfloras. Microfloras preserved in situ in the clay provide a link between floras in Tasmania and other Southern Hemisphere landmasses following onset of major glaciation in East Antarctica during the Eocene-Oligocene transition (c. 34 Ma). The Late Pleistocene “colluvium” preserves abundant fossil pollen of the shrub conifer genus Pherosphaera (al. Microstrobos). Assuming the parent plants had the same upper subalpine-alpine ecology as living Pherosphaera hookeriana, the microflora provides evidence for cold, wet conditions in the Port Davey lowlands during a low sea-level stand. The same data highlight the failure of Pherosphaera to regain its Pleistocene distribution during the Postglacial period. Our data are inconclusive whether Late Pleistocene conditions in Hannant Inlet were periglacial, i.e., the Oligocene sediments were turbated by freeze-thaw processes, or have been reworked by fluvial processes into the Pleistocene “colluvium”. Nevertheless, the inferred cold-climate is consistent with the former hypothesis. The sequence is sealed under cross-bedded coarse quartzite gravels of presumed Last Glacial Stage age. Article in Journal/Newspaper Antarc* Antarctica East Antarctica University of Tasmania: UTas ePrints Davey ENVELOPE(-58.567,-58.567,-61.967,-61.967) East Antarctica Papers and Proceedings of the Royal Society of Tasmania 148 43 59 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
210000 Science - General 260100 Geology Cenozoic palynostratigraphy Tasmania Antarctica South America Oligocene Pleistocene Lophosoria Embothrium Pherosphaera trans-oceanic migration The Royal Society of Tasmania natural history science papers & proceedings Australia |
spellingShingle |
210000 Science - General 260100 Geology Cenozoic palynostratigraphy Tasmania Antarctica South America Oligocene Pleistocene Lophosoria Embothrium Pherosphaera trans-oceanic migration The Royal Society of Tasmania natural history science papers & proceedings Australia Macphail, MK Sharples, C Bowman, DMJS Wood, SW Haberle, S Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania |
topic_facet |
210000 Science - General 260100 Geology Cenozoic palynostratigraphy Tasmania Antarctica South America Oligocene Pleistocene Lophosoria Embothrium Pherosphaera trans-oceanic migration The Royal Society of Tasmania natural history science papers & proceedings Australia |
description |
Cut-back of a sea-cliff at Hannant Inlet in remote South-West Tasmania has exposed Oligocene clays buried under Late Pleistocene “colluvium” from which abundant wood fragments protrude. The two units are separated by a transitional interval defined by mixed Oligocene and Pleistocene microfloras. Microfloras preserved in situ in the clay provide a link between floras in Tasmania and other Southern Hemisphere landmasses following onset of major glaciation in East Antarctica during the Eocene-Oligocene transition (c. 34 Ma). The Late Pleistocene “colluvium” preserves abundant fossil pollen of the shrub conifer genus Pherosphaera (al. Microstrobos). Assuming the parent plants had the same upper subalpine-alpine ecology as living Pherosphaera hookeriana, the microflora provides evidence for cold, wet conditions in the Port Davey lowlands during a low sea-level stand. The same data highlight the failure of Pherosphaera to regain its Pleistocene distribution during the Postglacial period. Our data are inconclusive whether Late Pleistocene conditions in Hannant Inlet were periglacial, i.e., the Oligocene sediments were turbated by freeze-thaw processes, or have been reworked by fluvial processes into the Pleistocene “colluvium”. Nevertheless, the inferred cold-climate is consistent with the former hypothesis. The sequence is sealed under cross-bedded coarse quartzite gravels of presumed Last Glacial Stage age. |
format |
Article in Journal/Newspaper |
author |
Macphail, MK Sharples, C Bowman, DMJS Wood, SW Haberle, S |
author_facet |
Macphail, MK Sharples, C Bowman, DMJS Wood, SW Haberle, S |
author_sort |
Macphail, MK |
title |
Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania |
title_short |
Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania |
title_full |
Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania |
title_fullStr |
Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania |
title_full_unstemmed |
Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania |
title_sort |
coastal erosion reveals a potentially unique oligocene and possible periglacial sequence at present-day sea level in port davey, remote south-west tasmania |
publishDate |
2014 |
url |
https://eprints.utas.edu.au/23202/ https://eprints.utas.edu.au/23202/7/04%20_McPhail.pdf |
long_lat |
ENVELOPE(-58.567,-58.567,-61.967,-61.967) |
geographic |
Davey East Antarctica |
geographic_facet |
Davey East Antarctica |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_relation |
https://eprints.utas.edu.au/23202/7/04%20_McPhail.pdf Macphail, MK, Sharples, C, Bowman, DMJS, Wood, SW and Haberle, S 2014 , 'Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania' , Papers and Proceedings of the Royal Society of Tasmania, vol. 148 , pp. 43-59 , doi:10.26749/rstpp.148.43 <http://dx.doi.org/10.26749/rstpp.148.43>. |
op_rights |
cc_utas |
op_doi |
https://doi.org/10.26749/rstpp.148.43 |
container_title |
Papers and Proceedings of the Royal Society of Tasmania |
container_volume |
148 |
container_start_page |
43 |
op_container_end_page |
59 |
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1766276121044713472 |