Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica
The question whether Cenozoic climate was warm enough to support a substantial vegetation cover on the Antarctic continent is of great significance to the ongoing controversial debate on the dynamic behaviour of Antarctic land ice during the transition from a greenhouse to an icehouse world. Here we...
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:26472 2023-05-15T13:35:33+02:00 Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica Salzmann, Ulrich Strother, Stephanie Sangiorgi, Francesca Bijl, Peter Pross, Jorg Woodward, John Escutia, Carlota Brinkhuis, Henk 2016-03 text https://nrl.northumbria.ac.uk/id/eprint/26472/ http://meetingorganizer.copernicus.org/EGU2016/EGU2016-2717.pdf https://nrl.northumbria.ac.uk/id/eprint/26472/1/EGU2016-2717.pdf en eng https://nrl.northumbria.ac.uk/id/eprint/26472/1/EGU2016-2717.pdf Salzmann, Ulrich, Strother, Stephanie, Sangiorgi, Francesca, Bijl, Peter, Pross, Jorg, Woodward, John, Escutia, Carlota and Brinkhuis, Henk (2016) Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica. In: EGU General Assembly 2016, 17th - 22nd April 2016, Vienna, Austria. cc_by CC-BY F600 Geology Conference or Workshop Item NonPeerReviewed 2016 ftunivnorthumb 2022-09-25T06:03:44Z The question whether Cenozoic climate was warm enough to support a substantial vegetation cover on the Antarctic continent is of great significance to the ongoing controversial debate on the dynamic behaviour of Antarctic land ice during the transition from a greenhouse to an icehouse world. Here we present palynological results from an Oligocene to Miocene sediment record provided by the Integrated Ocean Drilling Program Expedition 318 to the Wilkes Land margin (East Antarctica). The Oligocene assemblages (33.9-23 Ma) are dominated by pollen and spores from temperate forest and sub-Antarctic shrub vegetation inhabiting different altitudinal zones. These include a lowland cold temperate forest with Dacrydium and Lagarostrobos (both common in southern forests of New Zealand and Tasmania today) and a high altitude tundra shrubland comprising Microcachrys, Nothofagus (southern beech) and Podocarpaceae conifers. A decline in pollen percentages of Dacrydium and Lagarostrobos and absence of Proteaceae indicate climate cooling during the late Oligocene (�25-23 Ma). However, the continuous presence of Lagarostrobos suggests that the full transition to a tundra environment had not yet occurred and climate on Wilkes Land during the late Oligocene was still warm enough to support forest vegetation in sheltered areas. Temperature reconstructions derived from the fossil pollen assemblages using the Coexistence Approach suggest mean annual temperatures (MATs) between 6.7-13.7�C during the early Oligocene and a drop of minimum MATs to 5.8�C in the late Oligocene. Pollen of “unambiguous” forest indicators, such as Lagarostrobos, are absent in the Miocene sediment record (16.2 -12.5 Ma) but temperatures were still high enough (minimum MATs > 5�C) to sustain a woody sub-Antarctic vegetation under partially ice-free conditions. Wilkes Land provides a unique record of Antarctic vegetation change from a subtropical, highly diverse Eocene rainforest to an Oligocene cold temperate forest and an impoverished Miocene sub Antarctic ... Conference Object Antarc* Antarctic Antarctica East Antarctica Tundra Wilkes Land Northumbria University, Newcastle: Northumbria Research Link (NRL) Antarctic East Antarctica New Zealand The Antarctic Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) |
institution |
Open Polar |
collection |
Northumbria University, Newcastle: Northumbria Research Link (NRL) |
op_collection_id |
ftunivnorthumb |
language |
English |
topic |
F600 Geology |
spellingShingle |
F600 Geology Salzmann, Ulrich Strother, Stephanie Sangiorgi, Francesca Bijl, Peter Pross, Jorg Woodward, John Escutia, Carlota Brinkhuis, Henk Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica |
topic_facet |
F600 Geology |
description |
The question whether Cenozoic climate was warm enough to support a substantial vegetation cover on the Antarctic continent is of great significance to the ongoing controversial debate on the dynamic behaviour of Antarctic land ice during the transition from a greenhouse to an icehouse world. Here we present palynological results from an Oligocene to Miocene sediment record provided by the Integrated Ocean Drilling Program Expedition 318 to the Wilkes Land margin (East Antarctica). The Oligocene assemblages (33.9-23 Ma) are dominated by pollen and spores from temperate forest and sub-Antarctic shrub vegetation inhabiting different altitudinal zones. These include a lowland cold temperate forest with Dacrydium and Lagarostrobos (both common in southern forests of New Zealand and Tasmania today) and a high altitude tundra shrubland comprising Microcachrys, Nothofagus (southern beech) and Podocarpaceae conifers. A decline in pollen percentages of Dacrydium and Lagarostrobos and absence of Proteaceae indicate climate cooling during the late Oligocene (�25-23 Ma). However, the continuous presence of Lagarostrobos suggests that the full transition to a tundra environment had not yet occurred and climate on Wilkes Land during the late Oligocene was still warm enough to support forest vegetation in sheltered areas. Temperature reconstructions derived from the fossil pollen assemblages using the Coexistence Approach suggest mean annual temperatures (MATs) between 6.7-13.7�C during the early Oligocene and a drop of minimum MATs to 5.8�C in the late Oligocene. Pollen of “unambiguous” forest indicators, such as Lagarostrobos, are absent in the Miocene sediment record (16.2 -12.5 Ma) but temperatures were still high enough (minimum MATs > 5�C) to sustain a woody sub-Antarctic vegetation under partially ice-free conditions. Wilkes Land provides a unique record of Antarctic vegetation change from a subtropical, highly diverse Eocene rainforest to an Oligocene cold temperate forest and an impoverished Miocene sub Antarctic ... |
format |
Conference Object |
author |
Salzmann, Ulrich Strother, Stephanie Sangiorgi, Francesca Bijl, Peter Pross, Jorg Woodward, John Escutia, Carlota Brinkhuis, Henk |
author_facet |
Salzmann, Ulrich Strother, Stephanie Sangiorgi, Francesca Bijl, Peter Pross, Jorg Woodward, John Escutia, Carlota Brinkhuis, Henk |
author_sort |
Salzmann, Ulrich |
title |
Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica |
title_short |
Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica |
title_full |
Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica |
title_fullStr |
Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica |
title_full_unstemmed |
Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica |
title_sort |
oligocene to miocene terrestrial climate change and the demise of forests on wilkes land, east antarctica |
publishDate |
2016 |
url |
https://nrl.northumbria.ac.uk/id/eprint/26472/ http://meetingorganizer.copernicus.org/EGU2016/EGU2016-2717.pdf https://nrl.northumbria.ac.uk/id/eprint/26472/1/EGU2016-2717.pdf |
long_lat |
ENVELOPE(120.000,120.000,-69.000,-69.000) |
geographic |
Antarctic East Antarctica New Zealand The Antarctic Wilkes Land |
geographic_facet |
Antarctic East Antarctica New Zealand The Antarctic Wilkes Land |
genre |
Antarc* Antarctic Antarctica East Antarctica Tundra Wilkes Land |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Tundra Wilkes Land |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/26472/1/EGU2016-2717.pdf Salzmann, Ulrich, Strother, Stephanie, Sangiorgi, Francesca, Bijl, Peter, Pross, Jorg, Woodward, John, Escutia, Carlota and Brinkhuis, Henk (2016) Oligocene to Miocene terrestrial climate change and the demise of forests on Wilkes Land, East Antarctica. In: EGU General Assembly 2016, 17th - 22nd April 2016, Vienna, Austria. |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
_version_ |
1766067186773786624 |