Physical Properties and Age of Mid-slope Sediments Dredged from the Eastern Australian Continental Margin and the Implications for Continental Margin Erosion Processes
A large number of submarine landslides were identified on the continental slope on the Eastern Australian margin during voyages aboard the RV Southern Surveyor in 2008. Preliminary sedimentological analysis as well as geotechnical and biostratigraphic data determined for mid-slope dredge samples are...
Main Authors: | , , , , , , , |
---|---|
Format: | Text |
Language: | unknown |
Published: |
University of New Hampshire Scholars' Repository
2010
|
Subjects: | |
Online Access: | https://scholars.unh.edu/ccom/524 http://abstractsearch.agu.org/meetings/2010/FM/OS22C-01.html |
id |
ftuninhampshire:oai:scholars.unh.edu:ccom-1524 |
---|---|
record_format |
openpolar |
spelling |
ftuninhampshire:oai:scholars.unh.edu:ccom-1524 2023-05-15T13:41:56+02:00 Physical Properties and Age of Mid-slope Sediments Dredged from the Eastern Australian Continental Margin and the Implications for Continental Margin Erosion Processes Hubble, T Yu, P Airey, D Clarke, S L. Boyd, R Keene, J Exon, N Gardner, James V. 2010-12-01T08:00:00Z https://scholars.unh.edu/ccom/524 http://abstractsearch.agu.org/meetings/2010/FM/OS22C-01.html unknown University of New Hampshire Scholars' Repository https://scholars.unh.edu/ccom/524 http://abstractsearch.agu.org/meetings/2010/FM/OS22C-01.html Center for Coastal and Ocean Mapping Oceanography and Atmospheric Sciences and Meteorology text 2010 ftuninhampshire 2023-01-30T21:32:51Z A large number of submarine landslides were identified on the continental slope on the Eastern Australian margin during voyages aboard the RV Southern Surveyor in 2008. Preliminary sedimentological analysis as well as geotechnical and biostratigraphic data determined for mid-slope dredge samples are reported. The dredge samples are normally-consolidated, calcareous sandy-muds of Neogene age and were recovered from submarine scarps located on the mid-continental slope. These scarps probably represent submarine landslide failure surfaces. Slope stability modelling using classical soil mechanics techniques and measured sediment shear-strengths indicates that the slopes should be stable; however, the ubiquity of mid-slope slides on this margin indicates that their occurrence is relatively common and that submarine-sliding should probably be considered to be a normal characteristic of the margin as suggested by Boyd et al (2010). While this presents something of an interpretational paradox, it nevertheless indicates that an, as yet, unidentified mechanism acts to reduce the shear resistance of these sediments to very low values which enables the slope failures to occur. It is suspected that the expansion of the Antarctic Icesheet in Mid-Miocene time and the consequent large-scale production of cold, equator-ward migrating, bottom water has caused significant erosion and removal of material from mid-slope and lower slope of the Australian continental margin in the Tasman Sea since the Mid-Miocene. Such a process would help to explain the exposure of hard Palaeozoic basement rocks along much of the southern part of the Eastern Australian continental margin. It is also suspected that erosion due to equator-ward moving bottom water effectively and progressively removed material from the toe of the continental slope sediment wedge. This rendered the slope sediments that were deposited throughout the Tertiary more susceptible to mass failure than would have otherwise been the case. Reference: Boyd, R., Keene, J., Hubble, ... Text Antarc* Antarctic University of New Hampshire: Scholars Repository Antarctic The Antarctic Hubble ENVELOPE(158.317,158.317,-80.867,-80.867) The Toe ENVELOPE(-59.167,-59.167,-62.333,-62.333) |
institution |
Open Polar |
collection |
University of New Hampshire: Scholars Repository |
op_collection_id |
ftuninhampshire |
language |
unknown |
topic |
Oceanography and Atmospheric Sciences and Meteorology |
spellingShingle |
Oceanography and Atmospheric Sciences and Meteorology Hubble, T Yu, P Airey, D Clarke, S L. Boyd, R Keene, J Exon, N Gardner, James V. Physical Properties and Age of Mid-slope Sediments Dredged from the Eastern Australian Continental Margin and the Implications for Continental Margin Erosion Processes |
topic_facet |
Oceanography and Atmospheric Sciences and Meteorology |
description |
A large number of submarine landslides were identified on the continental slope on the Eastern Australian margin during voyages aboard the RV Southern Surveyor in 2008. Preliminary sedimentological analysis as well as geotechnical and biostratigraphic data determined for mid-slope dredge samples are reported. The dredge samples are normally-consolidated, calcareous sandy-muds of Neogene age and were recovered from submarine scarps located on the mid-continental slope. These scarps probably represent submarine landslide failure surfaces. Slope stability modelling using classical soil mechanics techniques and measured sediment shear-strengths indicates that the slopes should be stable; however, the ubiquity of mid-slope slides on this margin indicates that their occurrence is relatively common and that submarine-sliding should probably be considered to be a normal characteristic of the margin as suggested by Boyd et al (2010). While this presents something of an interpretational paradox, it nevertheless indicates that an, as yet, unidentified mechanism acts to reduce the shear resistance of these sediments to very low values which enables the slope failures to occur. It is suspected that the expansion of the Antarctic Icesheet in Mid-Miocene time and the consequent large-scale production of cold, equator-ward migrating, bottom water has caused significant erosion and removal of material from mid-slope and lower slope of the Australian continental margin in the Tasman Sea since the Mid-Miocene. Such a process would help to explain the exposure of hard Palaeozoic basement rocks along much of the southern part of the Eastern Australian continental margin. It is also suspected that erosion due to equator-ward moving bottom water effectively and progressively removed material from the toe of the continental slope sediment wedge. This rendered the slope sediments that were deposited throughout the Tertiary more susceptible to mass failure than would have otherwise been the case. Reference: Boyd, R., Keene, J., Hubble, ... |
format |
Text |
author |
Hubble, T Yu, P Airey, D Clarke, S L. Boyd, R Keene, J Exon, N Gardner, James V. |
author_facet |
Hubble, T Yu, P Airey, D Clarke, S L. Boyd, R Keene, J Exon, N Gardner, James V. |
author_sort |
Hubble, T |
title |
Physical Properties and Age of Mid-slope Sediments Dredged from the Eastern Australian Continental Margin and the Implications for Continental Margin Erosion Processes |
title_short |
Physical Properties and Age of Mid-slope Sediments Dredged from the Eastern Australian Continental Margin and the Implications for Continental Margin Erosion Processes |
title_full |
Physical Properties and Age of Mid-slope Sediments Dredged from the Eastern Australian Continental Margin and the Implications for Continental Margin Erosion Processes |
title_fullStr |
Physical Properties and Age of Mid-slope Sediments Dredged from the Eastern Australian Continental Margin and the Implications for Continental Margin Erosion Processes |
title_full_unstemmed |
Physical Properties and Age of Mid-slope Sediments Dredged from the Eastern Australian Continental Margin and the Implications for Continental Margin Erosion Processes |
title_sort |
physical properties and age of mid-slope sediments dredged from the eastern australian continental margin and the implications for continental margin erosion processes |
publisher |
University of New Hampshire Scholars' Repository |
publishDate |
2010 |
url |
https://scholars.unh.edu/ccom/524 http://abstractsearch.agu.org/meetings/2010/FM/OS22C-01.html |
long_lat |
ENVELOPE(158.317,158.317,-80.867,-80.867) ENVELOPE(-59.167,-59.167,-62.333,-62.333) |
geographic |
Antarctic The Antarctic Hubble The Toe |
geographic_facet |
Antarctic The Antarctic Hubble The Toe |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Center for Coastal and Ocean Mapping |
op_relation |
https://scholars.unh.edu/ccom/524 http://abstractsearch.agu.org/meetings/2010/FM/OS22C-01.html |
_version_ |
1766160716858916864 |