Bathymetry of Valdivia Bank, Walvis Ridge, South Atlantic Ocean: Implications for Structure and Geologic History of a Hot Spot Plateau
Abstract Valdivia Bank is an oceanic plateau in the South Atlantic formed by hot spot magmatism at the Mid‐Atlantic Ridge during the Late Cretaceous. It is part of the Walvis Ridge, an aseismic ridge and seamount chain widely considered to be formed by age‐progressive volcanism from the Tristan‐Goug...
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ftdoajarticles:oai:doaj.org/article:b0a12e20b978439ebf1e30f3882e49c0 2023-12-03T10:30:20+01:00 Bathymetry of Valdivia Bank, Walvis Ridge, South Atlantic Ocean: Implications for Structure and Geologic History of a Hot Spot Plateau E. Contreras P. Jiménez García W. W. Sager S. Thoram K. Hoernle R. Sarralde H. Zhou 2022-11-01T00:00:00Z https://doi.org/10.1029/2022GC010624 https://doaj.org/article/b0a12e20b978439ebf1e30f3882e49c0 EN eng Wiley https://doi.org/10.1029/2022GC010624 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2022GC010624 https://doaj.org/article/b0a12e20b978439ebf1e30f3882e49c0 Geochemistry, Geophysics, Geosystems, Vol 23, Iss 11, Pp n/a-n/a (2022) multibeam bathymetry Walvis Ridge oceanic plateau hot spot volcanism seamount Valdivia Bank Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.1029/2022GC010624 2023-11-05T01:35:55Z Abstract Valdivia Bank is an oceanic plateau in the South Atlantic formed by hot spot magmatism at the Mid‐Atlantic Ridge during the Late Cretaceous. It is part of the Walvis Ridge, an aseismic ridge and seamount chain widely considered to be formed by age‐progressive volcanism from the Tristan‐Gough plume. To better understand the formation and history of this edifice, we developed a bathymetric map of Valdivia Bank by merging available multibeam echosounder data sets with a bathymetry grid based mainly on satellite altimetry (SRTM15+). The bathymetric map reveals previously unresolved features including extensive rift grabens, volcanic mounds and knolls, and large‐scale sediment transport systems. After Valdivia Bank was emplaced and probably eroded at sea level, it underwent a period of rifting, followed by a secondary magmatic pulse that caused regional uplift to sea‐level, followed by subsidence to current depths. Shallow banks at depths of ∼1,000 m are the result of a thick sediment pile atop uplifted volcanic crust. Several shallower mounds (∼1,000–520 m) and a guyot (∼220 m) likely resulted from coral reef growth atop one or more volcanic pedestals formed during the younger Cenozoic magmatic event. As sediments accumulated on the shallow platforms, sediment transport systems developed as gullies, channels and mass transport deposits carved valleys and troughs, shedding sediment into abyssal fans at the plateau base. The new bathymetric map demonstrates that oceanic plateaus are geologically active long after initial emplacement. Article in Journal/Newspaper South Atlantic Ocean Directory of Open Access Journals: DOAJ Articles Gough ENVELOPE(159.367,159.367,-81.633,-81.633) Mid-Atlantic Ridge Tristan ENVELOPE(140.900,140.900,-66.735,-66.735) Geochemistry, Geophysics, Geosystems 23 11 |
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ftdoajarticles |
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topic |
multibeam bathymetry Walvis Ridge oceanic plateau hot spot volcanism seamount Valdivia Bank Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
spellingShingle |
multibeam bathymetry Walvis Ridge oceanic plateau hot spot volcanism seamount Valdivia Bank Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 E. Contreras P. Jiménez García W. W. Sager S. Thoram K. Hoernle R. Sarralde H. Zhou Bathymetry of Valdivia Bank, Walvis Ridge, South Atlantic Ocean: Implications for Structure and Geologic History of a Hot Spot Plateau |
topic_facet |
multibeam bathymetry Walvis Ridge oceanic plateau hot spot volcanism seamount Valdivia Bank Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
description |
Abstract Valdivia Bank is an oceanic plateau in the South Atlantic formed by hot spot magmatism at the Mid‐Atlantic Ridge during the Late Cretaceous. It is part of the Walvis Ridge, an aseismic ridge and seamount chain widely considered to be formed by age‐progressive volcanism from the Tristan‐Gough plume. To better understand the formation and history of this edifice, we developed a bathymetric map of Valdivia Bank by merging available multibeam echosounder data sets with a bathymetry grid based mainly on satellite altimetry (SRTM15+). The bathymetric map reveals previously unresolved features including extensive rift grabens, volcanic mounds and knolls, and large‐scale sediment transport systems. After Valdivia Bank was emplaced and probably eroded at sea level, it underwent a period of rifting, followed by a secondary magmatic pulse that caused regional uplift to sea‐level, followed by subsidence to current depths. Shallow banks at depths of ∼1,000 m are the result of a thick sediment pile atop uplifted volcanic crust. Several shallower mounds (∼1,000–520 m) and a guyot (∼220 m) likely resulted from coral reef growth atop one or more volcanic pedestals formed during the younger Cenozoic magmatic event. As sediments accumulated on the shallow platforms, sediment transport systems developed as gullies, channels and mass transport deposits carved valleys and troughs, shedding sediment into abyssal fans at the plateau base. The new bathymetric map demonstrates that oceanic plateaus are geologically active long after initial emplacement. |
format |
Article in Journal/Newspaper |
author |
E. Contreras P. Jiménez García W. W. Sager S. Thoram K. Hoernle R. Sarralde H. Zhou |
author_facet |
E. Contreras P. Jiménez García W. W. Sager S. Thoram K. Hoernle R. Sarralde H. Zhou |
author_sort |
E. Contreras |
title |
Bathymetry of Valdivia Bank, Walvis Ridge, South Atlantic Ocean: Implications for Structure and Geologic History of a Hot Spot Plateau |
title_short |
Bathymetry of Valdivia Bank, Walvis Ridge, South Atlantic Ocean: Implications for Structure and Geologic History of a Hot Spot Plateau |
title_full |
Bathymetry of Valdivia Bank, Walvis Ridge, South Atlantic Ocean: Implications for Structure and Geologic History of a Hot Spot Plateau |
title_fullStr |
Bathymetry of Valdivia Bank, Walvis Ridge, South Atlantic Ocean: Implications for Structure and Geologic History of a Hot Spot Plateau |
title_full_unstemmed |
Bathymetry of Valdivia Bank, Walvis Ridge, South Atlantic Ocean: Implications for Structure and Geologic History of a Hot Spot Plateau |
title_sort |
bathymetry of valdivia bank, walvis ridge, south atlantic ocean: implications for structure and geologic history of a hot spot plateau |
publisher |
Wiley |
publishDate |
2022 |
url |
https://doi.org/10.1029/2022GC010624 https://doaj.org/article/b0a12e20b978439ebf1e30f3882e49c0 |
long_lat |
ENVELOPE(159.367,159.367,-81.633,-81.633) ENVELOPE(140.900,140.900,-66.735,-66.735) |
geographic |
Gough Mid-Atlantic Ridge Tristan |
geographic_facet |
Gough Mid-Atlantic Ridge Tristan |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Geochemistry, Geophysics, Geosystems, Vol 23, Iss 11, Pp n/a-n/a (2022) |
op_relation |
https://doi.org/10.1029/2022GC010624 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2022GC010624 https://doaj.org/article/b0a12e20b978439ebf1e30f3882e49c0 |
op_doi |
https://doi.org/10.1029/2022GC010624 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
23 |
container_issue |
11 |
_version_ |
1784256109514588160 |