Southern high latitude vegetation change across the Drake Passage region linked to prolonged intervals of climate cooling during the early Oligocene
International audience The possible causes of the onset of Antarctic glaciation around the Eocene-Oligocene Transition (EOT), approximately 34 million years ago (~34Ma), are poorly understood. Uncertainties particularly remain over the role of the Drake Passage opening on the development of the Anta...
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Language: | English |
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HAL CCSD
2021
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Online Access: | https://hal.science/hal-03503461 https://doi.org/10.5194/egusphere-egu21-9503 |
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ftceafr:oai:HAL:hal-03503461v1 |
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openpolar |
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Open Polar |
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HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives) |
op_collection_id |
ftceafr |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology [SDE.MCG]Environmental Sciences/Global Changes Thompson, Nick Salzmann, Ulrich López Quirós, Adrián Escutia, Carlota Bijl, Peter Hoem, Frida Etourneau, Johan Sicre, Marie-Alexandrine Roignant, Sabine Amoo, Michael Southern high latitude vegetation change across the Drake Passage region linked to prolonged intervals of climate cooling during the early Oligocene |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience The possible causes of the onset of Antarctic glaciation around the Eocene-Oligocene Transition (EOT), approximately 34 million years ago (~34Ma), are poorly understood. Uncertainties particularly remain over the role of the Drake Passage opening on the development of the Antarctic Circumpolar Current (ACC), and how this affected both marine and terrestrial environments. A major obstacle in understanding the role of the opening Drake Passage and ACC in Cenozoic climate changes has been the lack of continuous records spanning the EOT from the region. Here we present new palynomorph data from ODP Leg 113 Site 696 Hole B, recording changes in terrestrial environments and paleoclimate across the EOT. The sporomorph assemblage reveals the presence of Nothofagus-dominated forests with secondary Podocarpaceae and an understory of angiosperms and cryptogams growing across much of the Northern Antarctic Peninsula and South Orkney Microcontinent during the late Eocene (~37.60-34.95 Ma). Palaeoclimate reconstructions show that these forests grew under wet temperate conditions, with mean annual temperature and precipitation around 12°C and 1650mm, respectively. Today, similar temperate Nothofagus-dominated mixed-podocarp forests occur in the temperate Valdivian region of southern Chile. At the onset of the EOT, the palynomorph assemblage indicates an unusual expansion of gymnosperms and cryptogams, accompanied by a rapid increase in taxa diversity between ca. 34 and 32 Ma. Sporomorph based climate reconstructions do not provide evidence for an abrupt cooling at the EOT but reveal the onset of prolonged cooling phases throughout the early Oligocene. A contemporaneous increase in reworked Mesozoic sporomorphs at the EOT is likely to be linked to frequent glacial advances from the Antarctic Peninsula and South Orkney Microcontinent, although iceberg-rafted debris from Antarctica cannot be ruled out. We conclude that climate instability and glacial related disturbance at the onset of the EOT facilitated ... |
author2 |
Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) |
format |
Conference Object |
author |
Thompson, Nick Salzmann, Ulrich López Quirós, Adrián Escutia, Carlota Bijl, Peter Hoem, Frida Etourneau, Johan Sicre, Marie-Alexandrine Roignant, Sabine Amoo, Michael |
author_facet |
Thompson, Nick Salzmann, Ulrich López Quirós, Adrián Escutia, Carlota Bijl, Peter Hoem, Frida Etourneau, Johan Sicre, Marie-Alexandrine Roignant, Sabine Amoo, Michael |
author_sort |
Thompson, Nick |
title |
Southern high latitude vegetation change across the Drake Passage region linked to prolonged intervals of climate cooling during the early Oligocene |
title_short |
Southern high latitude vegetation change across the Drake Passage region linked to prolonged intervals of climate cooling during the early Oligocene |
title_full |
Southern high latitude vegetation change across the Drake Passage region linked to prolonged intervals of climate cooling during the early Oligocene |
title_fullStr |
Southern high latitude vegetation change across the Drake Passage region linked to prolonged intervals of climate cooling during the early Oligocene |
title_full_unstemmed |
Southern high latitude vegetation change across the Drake Passage region linked to prolonged intervals of climate cooling during the early Oligocene |
title_sort |
southern high latitude vegetation change across the drake passage region linked to prolonged intervals of climate cooling during the early oligocene |
publisher |
HAL CCSD |
publishDate |
2021 |
url |
https://hal.science/hal-03503461 https://doi.org/10.5194/egusphere-egu21-9503 |
op_coverage |
Vienne, France |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Drake Passage Iceberg* |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Drake Passage Iceberg* |
op_source |
EGU 2021 https://hal.science/hal-03503461 EGU 2021, Apr 2021, Vienne, France. ⟨10.5194/egusphere-egu21-9503⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/egusphere-egu21-9503 hal-03503461 https://hal.science/hal-03503461 doi:10.5194/egusphere-egu21-9503 |
op_doi |
https://doi.org/10.5194/egusphere-egu21-9503 |
_version_ |
1799482509922140160 |
spelling |
ftceafr:oai:HAL:hal-03503461v1 2024-05-19T07:29:56+00:00 Southern high latitude vegetation change across the Drake Passage region linked to prolonged intervals of climate cooling during the early Oligocene Thompson, Nick Salzmann, Ulrich López Quirós, Adrián Escutia, Carlota Bijl, Peter Hoem, Frida Etourneau, Johan Sicre, Marie-Alexandrine Roignant, Sabine Amoo, Michael Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) Vienne, France 2021-04 https://hal.science/hal-03503461 https://doi.org/10.5194/egusphere-egu21-9503 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/egusphere-egu21-9503 hal-03503461 https://hal.science/hal-03503461 doi:10.5194/egusphere-egu21-9503 EGU 2021 https://hal.science/hal-03503461 EGU 2021, Apr 2021, Vienne, France. ⟨10.5194/egusphere-egu21-9503⟩ [SDU.STU]Sciences of the Universe [physics]/Earth Sciences [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/conferenceObject Conference papers 2021 ftceafr https://doi.org/10.5194/egusphere-egu21-9503 2024-04-25T01:39:35Z International audience The possible causes of the onset of Antarctic glaciation around the Eocene-Oligocene Transition (EOT), approximately 34 million years ago (~34Ma), are poorly understood. Uncertainties particularly remain over the role of the Drake Passage opening on the development of the Antarctic Circumpolar Current (ACC), and how this affected both marine and terrestrial environments. A major obstacle in understanding the role of the opening Drake Passage and ACC in Cenozoic climate changes has been the lack of continuous records spanning the EOT from the region. Here we present new palynomorph data from ODP Leg 113 Site 696 Hole B, recording changes in terrestrial environments and paleoclimate across the EOT. The sporomorph assemblage reveals the presence of Nothofagus-dominated forests with secondary Podocarpaceae and an understory of angiosperms and cryptogams growing across much of the Northern Antarctic Peninsula and South Orkney Microcontinent during the late Eocene (~37.60-34.95 Ma). Palaeoclimate reconstructions show that these forests grew under wet temperate conditions, with mean annual temperature and precipitation around 12°C and 1650mm, respectively. Today, similar temperate Nothofagus-dominated mixed-podocarp forests occur in the temperate Valdivian region of southern Chile. At the onset of the EOT, the palynomorph assemblage indicates an unusual expansion of gymnosperms and cryptogams, accompanied by a rapid increase in taxa diversity between ca. 34 and 32 Ma. Sporomorph based climate reconstructions do not provide evidence for an abrupt cooling at the EOT but reveal the onset of prolonged cooling phases throughout the early Oligocene. A contemporaneous increase in reworked Mesozoic sporomorphs at the EOT is likely to be linked to frequent glacial advances from the Antarctic Peninsula and South Orkney Microcontinent, although iceberg-rafted debris from Antarctica cannot be ruled out. We conclude that climate instability and glacial related disturbance at the onset of the EOT facilitated ... Conference Object Antarc* Antarctic Antarctic Peninsula Antarctica Drake Passage Iceberg* HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives) |