Crustal structure beneath the Orange Basin, South Africa
Although the development of passive margins has been extensively studied over a number of decades, significant questions remain on how mantle and crustal dynamics interact to generate the observed margin geometries. Here, we investigate the Orange Basin, located on the south-west African continental...
Published in: | South African Journal of Geology |
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_236001 2023-05-15T18:21:05+02:00 Crustal structure beneath the Orange Basin, South Africa Hirsch, K. Scheck-Wenderoth, M. Paton, D. Bauer, K. 4.3 Organic Geochemistry, 4.0 Chemistry and Material Cycles, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum 2007 application/pdf https://gfzpublic.gfz-potsdam.de/pubman/item/item_236001 unknown info:eu-repo/semantics/altIdentifier/doi/10.2113/gssajg.110.2-3.249 https://gfzpublic.gfz-potsdam.de/pubman/item/item_236001 info:eu-repo/semantics/openAccess South African Journal of Geology 550 - Earth sciences info:eu-repo/semantics/article 2007 ftgfzpotsdam https://doi.org/10.2113/gssajg.110.2-3.249 2022-09-14T05:54:27Z Although the development of passive margins has been extensively studied over a number of decades, significant questions remain on how mantle and crustal dynamics interact to generate the observed margin geometries. Here, we investigate the Orange Basin, located on the south-west African continental margin. The basin fill is considered to comprise a classic rift-drift passive margin sequence recording the break-up of Condwana and subsequent opening of the South Atlantic Ocean. Based on interpreted seismic reflection data, a 3D geological model was first constructed. Subsequently, an isostatic calculation (Airy´s model) using a homogeneous middle and lower crust was applied to this geological model to determine the position of the Moho for an isostatically balanced system. Isostatic sensitivity tests were applied to the model and their gravity response was validated against different crustal structures for the basin. The best-fit model requires dense, presumably mafic material, in the middle and lower crust beneath the basin and an abrupt change to less dense material near the coast to reproduce the observed gravity field. Article in Journal/Newspaper South Atlantic Ocean GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) South African Journal of Geology 110 2-3 249 260 |
institution |
Open Polar |
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GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
unknown |
topic |
550 - Earth sciences |
spellingShingle |
550 - Earth sciences Hirsch, K. Scheck-Wenderoth, M. Paton, D. Bauer, K. Crustal structure beneath the Orange Basin, South Africa |
topic_facet |
550 - Earth sciences |
description |
Although the development of passive margins has been extensively studied over a number of decades, significant questions remain on how mantle and crustal dynamics interact to generate the observed margin geometries. Here, we investigate the Orange Basin, located on the south-west African continental margin. The basin fill is considered to comprise a classic rift-drift passive margin sequence recording the break-up of Condwana and subsequent opening of the South Atlantic Ocean. Based on interpreted seismic reflection data, a 3D geological model was first constructed. Subsequently, an isostatic calculation (Airy´s model) using a homogeneous middle and lower crust was applied to this geological model to determine the position of the Moho for an isostatically balanced system. Isostatic sensitivity tests were applied to the model and their gravity response was validated against different crustal structures for the basin. The best-fit model requires dense, presumably mafic material, in the middle and lower crust beneath the basin and an abrupt change to less dense material near the coast to reproduce the observed gravity field. |
author2 |
4.3 Organic Geochemistry, 4.0 Chemistry and Material Cycles, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum |
format |
Article in Journal/Newspaper |
author |
Hirsch, K. Scheck-Wenderoth, M. Paton, D. Bauer, K. |
author_facet |
Hirsch, K. Scheck-Wenderoth, M. Paton, D. Bauer, K. |
author_sort |
Hirsch, K. |
title |
Crustal structure beneath the Orange Basin, South Africa |
title_short |
Crustal structure beneath the Orange Basin, South Africa |
title_full |
Crustal structure beneath the Orange Basin, South Africa |
title_fullStr |
Crustal structure beneath the Orange Basin, South Africa |
title_full_unstemmed |
Crustal structure beneath the Orange Basin, South Africa |
title_sort |
crustal structure beneath the orange basin, south africa |
publishDate |
2007 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_236001 |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
South African Journal of Geology |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.2113/gssajg.110.2-3.249 https://gfzpublic.gfz-potsdam.de/pubman/item/item_236001 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.2113/gssajg.110.2-3.249 |
container_title |
South African Journal of Geology |
container_volume |
110 |
container_issue |
2-3 |
container_start_page |
249 |
op_container_end_page |
260 |
_version_ |
1766200163614851072 |