Effects of biogenic silica on sediment compaction and slope stability on the Pacific margin of the Antarctic Peninsula
Abstract Analysis of physical properties measured on cores and on discrete samples collected by the Ocean Drilling Programme (ODP) Leg 178 on the Pacific margin of the Antarctic Peninsula reveals anomalous down‐hole curves of porosity, density, water content, and P‐wave velocity. These indicate an o...
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crwiley:10.1046/j.1365-2117.2003.00210.x 2024-06-02T07:57:33+00:00 Effects of biogenic silica on sediment compaction and slope stability on the Pacific margin of the Antarctic Peninsula Volpi, V. Camerlenghi, A. Hillenbrand, C.‐D. Rebesco, M. Ivaldi, R. 2003 http://dx.doi.org/10.1046/j.1365-2117.2003.00210.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2117.2003.00210.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2117.2003.00210.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Basin Research volume 15, issue 3, page 339-363 ISSN 0950-091X 1365-2117 journal-article 2003 crwiley https://doi.org/10.1046/j.1365-2117.2003.00210.x 2024-05-03T10:36:13Z Abstract Analysis of physical properties measured on cores and on discrete samples collected by the Ocean Drilling Programme (ODP) Leg 178 on the Pacific margin of the Antarctic Peninsula reveals anomalous down‐hole curves of porosity, density, water content, and P‐wave velocity. These indicate an overall trend of increasing porosity with depth and suggest that the drifts are mostly undercompacted. In one of the two boreholes analysed, a sharp decrease in porosity, matching increasing bulk sediment density and increasing compressional velocity occurs towards the base of the hole, which corresponds to a bottom‐simulating reflector in the seismic section. Analysis of seismic reflection, down‐hole logging, geotechnical and mineralogical data from two drilling sites indicates that the observed anomalous consolidation trends are a consequence of the presence of biogenic silica (diatom and radiolarian skeletons) even with a small to moderate amount. Above the bottom‐simulating reflector, intergranular contacts among whole or broken siliceous microfossils prevent normal sediment consolidation. Diagenetic alteration of biogenic opal‐A to opal‐CT causes a dramatic reduction of intra‐ and interskeletal porosity allowing sediments to consolidate at depth. This results in overpressuring and a decrease in the effective stress. Excess fluids are expelled towards the sediment surface through near vertical, small throw normal faults extending from the diagenetic front to the seafloor and affecting the stability of the submarine slope in the form of gravitational creep along a weakened surface. This work shows how physical properties of shallow fine‐grained marine sediments can be analysed as basin‐wide indicators of biogenic silica abundance. The diagenetic alteration of siliceous microfossils is a possible cause of slope instability along world continental margins where bottom‐simulating reflectors related to silica diagenesis are present at a regional scale. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Wiley Online Library Antarctic The Antarctic Antarctic Peninsula Pacific Basin Research 15 3 339 363 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract Analysis of physical properties measured on cores and on discrete samples collected by the Ocean Drilling Programme (ODP) Leg 178 on the Pacific margin of the Antarctic Peninsula reveals anomalous down‐hole curves of porosity, density, water content, and P‐wave velocity. These indicate an overall trend of increasing porosity with depth and suggest that the drifts are mostly undercompacted. In one of the two boreholes analysed, a sharp decrease in porosity, matching increasing bulk sediment density and increasing compressional velocity occurs towards the base of the hole, which corresponds to a bottom‐simulating reflector in the seismic section. Analysis of seismic reflection, down‐hole logging, geotechnical and mineralogical data from two drilling sites indicates that the observed anomalous consolidation trends are a consequence of the presence of biogenic silica (diatom and radiolarian skeletons) even with a small to moderate amount. Above the bottom‐simulating reflector, intergranular contacts among whole or broken siliceous microfossils prevent normal sediment consolidation. Diagenetic alteration of biogenic opal‐A to opal‐CT causes a dramatic reduction of intra‐ and interskeletal porosity allowing sediments to consolidate at depth. This results in overpressuring and a decrease in the effective stress. Excess fluids are expelled towards the sediment surface through near vertical, small throw normal faults extending from the diagenetic front to the seafloor and affecting the stability of the submarine slope in the form of gravitational creep along a weakened surface. This work shows how physical properties of shallow fine‐grained marine sediments can be analysed as basin‐wide indicators of biogenic silica abundance. The diagenetic alteration of siliceous microfossils is a possible cause of slope instability along world continental margins where bottom‐simulating reflectors related to silica diagenesis are present at a regional scale. |
format |
Article in Journal/Newspaper |
author |
Volpi, V. Camerlenghi, A. Hillenbrand, C.‐D. Rebesco, M. Ivaldi, R. |
spellingShingle |
Volpi, V. Camerlenghi, A. Hillenbrand, C.‐D. Rebesco, M. Ivaldi, R. Effects of biogenic silica on sediment compaction and slope stability on the Pacific margin of the Antarctic Peninsula |
author_facet |
Volpi, V. Camerlenghi, A. Hillenbrand, C.‐D. Rebesco, M. Ivaldi, R. |
author_sort |
Volpi, V. |
title |
Effects of biogenic silica on sediment compaction and slope stability on the Pacific margin of the Antarctic Peninsula |
title_short |
Effects of biogenic silica on sediment compaction and slope stability on the Pacific margin of the Antarctic Peninsula |
title_full |
Effects of biogenic silica on sediment compaction and slope stability on the Pacific margin of the Antarctic Peninsula |
title_fullStr |
Effects of biogenic silica on sediment compaction and slope stability on the Pacific margin of the Antarctic Peninsula |
title_full_unstemmed |
Effects of biogenic silica on sediment compaction and slope stability on the Pacific margin of the Antarctic Peninsula |
title_sort |
effects of biogenic silica on sediment compaction and slope stability on the pacific margin of the antarctic peninsula |
publisher |
Wiley |
publishDate |
2003 |
url |
http://dx.doi.org/10.1046/j.1365-2117.2003.00210.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2117.2003.00210.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2117.2003.00210.x |
geographic |
Antarctic The Antarctic Antarctic Peninsula Pacific |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Pacific |
genre |
Antarc* Antarctic Antarctic Peninsula |
genre_facet |
Antarc* Antarctic Antarctic Peninsula |
op_source |
Basin Research volume 15, issue 3, page 339-363 ISSN 0950-091X 1365-2117 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1046/j.1365-2117.2003.00210.x |
container_title |
Basin Research |
container_volume |
15 |
container_issue |
3 |
container_start_page |
339 |
op_container_end_page |
363 |
_version_ |
1800740715830968320 |