Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current
Thermohaline oceanic currents influence global heat transfer, controlling local and global variations in climate, biodiversity, and the terrestrial biosphere. Paleoceanographic studies typically use biostratigraphic and geochemical proxies to reconstruct the dynamics of these currents in Earth’s anc...
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ftumanchesterpub:oai:pure.atira.dk:publications/79c4af3f-16f6-4256-b6a2-d79051f2d451 2023-11-12T04:22:29+01:00 Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current Jackson, Christopher Magee, Craig Hunt-Stewart, Esther 2017-10-24 https://research.manchester.ac.uk/en/publications/79c4af3f-16f6-4256-b6a2-d79051f2d451 https://doi.org/10.31223/OSF.IO/ADW6S eng eng info:eu-repo/semantics/openAccess Jackson , C , Magee , C & Hunt-Stewart , E 2017 ' Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current ' . https://doi.org/10.31223/OSF.IO/ADW6S workingPaper 2017 ftumanchesterpub https://doi.org/10.31223/OSF.IO/ADW6S 2023-10-30T09:10:43Z Thermohaline oceanic currents influence global heat transfer, controlling local and global variations in climate, biodiversity, and the terrestrial biosphere. Paleoceanographic studies typically use biostratigraphic and geochemical proxies to reconstruct the dynamics of these currents in Earth’s ancient oceans, although seismic reflection data have also been successfully employed, most commonly in the North Atlantic Ocean. Here we use 2D seismic reflection data from the Ceduna Sub-basin, Great Australian Bight, offshore southern Australia to describe middle Eocene-to-Recent contourites deposited within an overall carbonate-dominated succession. These deposits comprise large (100 m wavelength by up to 50 m tall) bedforms and deep (10–90 m), wide (up to 3 km) erosional scours. The scours are particularly well-developed at one specific stratigraphic level, defining moats that encircle Middle Eocene shield volcanoes, which formed syn-depositional bathymetric highs. We suggest that sediment erosion, transport, and deposition record middle Eocene initiation of the Leeuwin Current, one of the most important ocean currents in the southern hemisphere. Deepest seabed scouring occurs within the middle of the middle Eocene-to-Recent sequence, and may reflect middle Miocene waxing of the so-called ‘proto-Leeuwin Current’, possibly driven by changes in ocean circulation patterns caused by the Miocene Global Optimum. The results of this seismic reflection-based study are consistent with results derived from other paleoceanographic proxies, thereby highlighting the continued key role seismic reflection data have in understanding the occurrence, geographical distribution, and significance of ancient ocean currents. Report North Atlantic The University of Manchester: Research Explorer |
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The University of Manchester: Research Explorer |
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ftumanchesterpub |
language |
English |
description |
Thermohaline oceanic currents influence global heat transfer, controlling local and global variations in climate, biodiversity, and the terrestrial biosphere. Paleoceanographic studies typically use biostratigraphic and geochemical proxies to reconstruct the dynamics of these currents in Earth’s ancient oceans, although seismic reflection data have also been successfully employed, most commonly in the North Atlantic Ocean. Here we use 2D seismic reflection data from the Ceduna Sub-basin, Great Australian Bight, offshore southern Australia to describe middle Eocene-to-Recent contourites deposited within an overall carbonate-dominated succession. These deposits comprise large (100 m wavelength by up to 50 m tall) bedforms and deep (10–90 m), wide (up to 3 km) erosional scours. The scours are particularly well-developed at one specific stratigraphic level, defining moats that encircle Middle Eocene shield volcanoes, which formed syn-depositional bathymetric highs. We suggest that sediment erosion, transport, and deposition record middle Eocene initiation of the Leeuwin Current, one of the most important ocean currents in the southern hemisphere. Deepest seabed scouring occurs within the middle of the middle Eocene-to-Recent sequence, and may reflect middle Miocene waxing of the so-called ‘proto-Leeuwin Current’, possibly driven by changes in ocean circulation patterns caused by the Miocene Global Optimum. The results of this seismic reflection-based study are consistent with results derived from other paleoceanographic proxies, thereby highlighting the continued key role seismic reflection data have in understanding the occurrence, geographical distribution, and significance of ancient ocean currents. |
format |
Report |
author |
Jackson, Christopher Magee, Craig Hunt-Stewart, Esther |
spellingShingle |
Jackson, Christopher Magee, Craig Hunt-Stewart, Esther Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current |
author_facet |
Jackson, Christopher Magee, Craig Hunt-Stewart, Esther |
author_sort |
Jackson, Christopher |
title |
Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current |
title_short |
Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current |
title_full |
Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current |
title_fullStr |
Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current |
title_full_unstemmed |
Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current |
title_sort |
cenozoic contourites in the eastern great australian bight, offshore southern australia: implications for the onset of the leeuwin current |
publishDate |
2017 |
url |
https://research.manchester.ac.uk/en/publications/79c4af3f-16f6-4256-b6a2-d79051f2d451 https://doi.org/10.31223/OSF.IO/ADW6S |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Jackson , C , Magee , C & Hunt-Stewart , E 2017 ' Cenozoic contourites in the eastern Great Australian Bight, offshore southern Australia: implications for the onset of the Leeuwin Current ' . https://doi.org/10.31223/OSF.IO/ADW6S |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.31223/OSF.IO/ADW6S |
_version_ |
1782337523668746240 |