Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin
A complex history of sediment deposition at the Argentine continental margin during the Plio-Pleistocene is indicated by the presence of a canyon system, submarine channels and sediment drifts. We use a dense grid of seismic reflection profiles together with bathymetric data to identify sedimentary...
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ftawi:oai:epic.awi.de:33334 2024-09-09T19:10:11+00:00 Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin Gruetzner, Jens Uenzelmann-Neben, Gabriele Franke, Dieter 2013 https://epic.awi.de/id/eprint/33334/ https://hdl.handle.net/10013/epic.41795 unknown Gruetzner, J. orcid:0000-0001-5445-2393 , Uenzelmann-Neben, G. orcid:0000-0002-0115-5923 and Franke, D. (2013) Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin , Colloquium of the DFG Priority Program SPP1375:South Atlantic Margin Processes and Links with onshore Evolution (SAMPLE), Heidelberg, 11 June 2013 - 14 June 2013 . hdl:10013/epic.41795 EPIC3Colloquium of the DFG Priority Program SPP1375:South Atlantic Margin Processes and Links with onshore Evolution (SAMPLE), Heidelberg, 2013-06-11-2013-06-14 Conference notRev 2013 ftawi 2024-06-24T04:07:26Z A complex history of sediment deposition at the Argentine continental margin during the Plio-Pleistocene is indicated by the presence of a canyon system, submarine channels and sediment drifts. We use a dense grid of seismic reflection profiles together with bathymetric data to identify sedimentary units, map depocenter geometries, separate along-slope from down-slope processes and relate depositional stages to past changes in climate, oceanography and tectonics. The topmost seismic unit in the working area (40 to 48°S) exhibits a variety of co-occurring seismic and morphological features that are diagnostic for both down-slope and along-slope sediment redistribution. In general, current controlled sedimentation is more obvious south of 45°S (“terraces sector”) while in the northern part (“canyons sector”) of the working area contouritic features are reshaped by cross-slope erosion through canyons. Within the canyons sector a slope plastered drift occurs in ~3000 m water depth seaward of the 3000 m isobath. The drift has a thickness of ~400 - 600 m and a width of ~10 - 20 km and can be traced for ~100 km within the working area. The feature likely is a northward extension of a current derived unit identified in the terraces sector and indicates that during the Plio-Pleistocene strong current controlled sedimentation occurred close to the interface between Lower Circumpolar Deep Water (LCDW) and Antarctic Bottom Water (AABW). Erosion via slope cutting canyons is most extensive in ~3000 m water depth at the central Argentine margin (43.5°S, 57.5°W) where multiple branches of the Ameghino canyon system join. None of the canyons in the working area cut into reflectors AR5/AR6 (~14 – 17 Ma), and only the main branches of the Ameghino canyon cut into reflector AR7 (~6 Ma) on the upper slope. Together with the fact that no buried canyons are observed this suggests that canyon development most likely occurred during the late Neogene possibly due to the buildup of slope instabilities caused by vigorous bottom current ... Conference Object Antarc* Antarctic Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Argentine |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
language |
unknown |
description |
A complex history of sediment deposition at the Argentine continental margin during the Plio-Pleistocene is indicated by the presence of a canyon system, submarine channels and sediment drifts. We use a dense grid of seismic reflection profiles together with bathymetric data to identify sedimentary units, map depocenter geometries, separate along-slope from down-slope processes and relate depositional stages to past changes in climate, oceanography and tectonics. The topmost seismic unit in the working area (40 to 48°S) exhibits a variety of co-occurring seismic and morphological features that are diagnostic for both down-slope and along-slope sediment redistribution. In general, current controlled sedimentation is more obvious south of 45°S (“terraces sector”) while in the northern part (“canyons sector”) of the working area contouritic features are reshaped by cross-slope erosion through canyons. Within the canyons sector a slope plastered drift occurs in ~3000 m water depth seaward of the 3000 m isobath. The drift has a thickness of ~400 - 600 m and a width of ~10 - 20 km and can be traced for ~100 km within the working area. The feature likely is a northward extension of a current derived unit identified in the terraces sector and indicates that during the Plio-Pleistocene strong current controlled sedimentation occurred close to the interface between Lower Circumpolar Deep Water (LCDW) and Antarctic Bottom Water (AABW). Erosion via slope cutting canyons is most extensive in ~3000 m water depth at the central Argentine margin (43.5°S, 57.5°W) where multiple branches of the Ameghino canyon system join. None of the canyons in the working area cut into reflectors AR5/AR6 (~14 – 17 Ma), and only the main branches of the Ameghino canyon cut into reflector AR7 (~6 Ma) on the upper slope. Together with the fact that no buried canyons are observed this suggests that canyon development most likely occurred during the late Neogene possibly due to the buildup of slope instabilities caused by vigorous bottom current ... |
format |
Conference Object |
author |
Gruetzner, Jens Uenzelmann-Neben, Gabriele Franke, Dieter |
spellingShingle |
Gruetzner, Jens Uenzelmann-Neben, Gabriele Franke, Dieter Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin |
author_facet |
Gruetzner, Jens Uenzelmann-Neben, Gabriele Franke, Dieter |
author_sort |
Gruetzner, Jens |
title |
Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin |
title_short |
Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin |
title_full |
Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin |
title_fullStr |
Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin |
title_full_unstemmed |
Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin |
title_sort |
late neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the argentine margin |
publishDate |
2013 |
url |
https://epic.awi.de/id/eprint/33334/ https://hdl.handle.net/10013/epic.41795 |
geographic |
Antarctic Argentine |
geographic_facet |
Antarctic Argentine |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
EPIC3Colloquium of the DFG Priority Program SPP1375:South Atlantic Margin Processes and Links with onshore Evolution (SAMPLE), Heidelberg, 2013-06-11-2013-06-14 |
op_relation |
Gruetzner, J. orcid:0000-0001-5445-2393 , Uenzelmann-Neben, G. orcid:0000-0002-0115-5923 and Franke, D. (2013) Late Neogene intensification of deep ocean circulation: evidence from seismic profiling of a mixed turbidite - contourite system at the Argentine Margin , Colloquium of the DFG Priority Program SPP1375:South Atlantic Margin Processes and Links with onshore Evolution (SAMPLE), Heidelberg, 11 June 2013 - 14 June 2013 . hdl:10013/epic.41795 |
_version_ |
1809824779712069632 |