Evolution of the Malvinas Plate South of Africa
We confirm that a Malvinas Plate is required in the Agulhas Basin during the Late Cretaceous because: (1) oblique Mercator plots of marine gravity show that fracture zones generated on the Agulhas rift, as well as the Agulhas Fracture Zone, do not lie on small circles about the 33o-28y South America...
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ftcaltechauth:oai:authors.library.caltech.edu:44971 2023-05-15T14:04:55+02:00 Evolution of the Malvinas Plate South of Africa Marks, K. M. Stock, J. M. 2001-07 https://authors.library.caltech.edu/44971/ https://resolver.caltech.edu/CaltechAUTHORS:20140416-090645328 unknown Springer Verlag Marks, K. M. and Stock, J. M. (2001) Evolution of the Malvinas Plate South of Africa. Marine Geophysical Researches, 22 (4). pp. 289-302. ISSN 0025-3235. doi:10.1023/A:1014638325616. https://resolver.caltech.edu/CaltechAUTHORS:20140416-090645328 <https://resolver.caltech.edu/CaltechAUTHORS:20140416-090645328> Article PeerReviewed 2001 ftcaltechauth https://doi.org/10.1023/A:1014638325616 2021-11-11T18:57:26Z We confirm that a Malvinas Plate is required in the Agulhas Basin during the Late Cretaceous because: (1) oblique Mercator plots of marine gravity show that fracture zones generated on the Agulhas rift, as well as the Agulhas Fracture Zone, do not lie on small circles about the 33o-28y South America-Africa stage pole and were therefore not formed by South America-Africa spreading, (2) the 33o-28y South America-Africa stage rotation does not bring 33o magnetic anomalies on the Malvinas Plate into alignment with their conjugates on the African Plate, and (3) errors in the 33o-28y South America-Africa stage rotation cannot account for the misalignment. We present improved Malvinas-Africa finite rotations determined by interpreting magnetic anomaly data in light of fracture zones and extinct spreading rift segments (the Agulhas rift) that are clearly revealed in satellite-derived marine gravity fields covering the Agulhas Basin. The tectonic history of the Malvinas Plate is chronicled through gravity field reconstructions that use the improved Malvinas-Africa finite rotations and more recent South America-Africa and Antarctica-Africa finite rotations. Newly-mapped triple junction traces on the Antarctic, South American, Malvinas, and African Plates, combined with geometric and magnetic constraints observed in the reconstructions, enable us to investigate the locations of the elusive western and southern boundaries of the Malvinas Plate. Article in Journal/Newspaper Antarc* Antarctic Antarctica Caltech Authors (California Institute of Technology) Antarctic The Antarctic Agulhas Basin ENVELOPE(27.000,27.000,-47.000,-47.000) |
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Caltech Authors (California Institute of Technology) |
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description |
We confirm that a Malvinas Plate is required in the Agulhas Basin during the Late Cretaceous because: (1) oblique Mercator plots of marine gravity show that fracture zones generated on the Agulhas rift, as well as the Agulhas Fracture Zone, do not lie on small circles about the 33o-28y South America-Africa stage pole and were therefore not formed by South America-Africa spreading, (2) the 33o-28y South America-Africa stage rotation does not bring 33o magnetic anomalies on the Malvinas Plate into alignment with their conjugates on the African Plate, and (3) errors in the 33o-28y South America-Africa stage rotation cannot account for the misalignment. We present improved Malvinas-Africa finite rotations determined by interpreting magnetic anomaly data in light of fracture zones and extinct spreading rift segments (the Agulhas rift) that are clearly revealed in satellite-derived marine gravity fields covering the Agulhas Basin. The tectonic history of the Malvinas Plate is chronicled through gravity field reconstructions that use the improved Malvinas-Africa finite rotations and more recent South America-Africa and Antarctica-Africa finite rotations. Newly-mapped triple junction traces on the Antarctic, South American, Malvinas, and African Plates, combined with geometric and magnetic constraints observed in the reconstructions, enable us to investigate the locations of the elusive western and southern boundaries of the Malvinas Plate. |
format |
Article in Journal/Newspaper |
author |
Marks, K. M. Stock, J. M. |
spellingShingle |
Marks, K. M. Stock, J. M. Evolution of the Malvinas Plate South of Africa |
author_facet |
Marks, K. M. Stock, J. M. |
author_sort |
Marks, K. M. |
title |
Evolution of the Malvinas Plate South of Africa |
title_short |
Evolution of the Malvinas Plate South of Africa |
title_full |
Evolution of the Malvinas Plate South of Africa |
title_fullStr |
Evolution of the Malvinas Plate South of Africa |
title_full_unstemmed |
Evolution of the Malvinas Plate South of Africa |
title_sort |
evolution of the malvinas plate south of africa |
publisher |
Springer Verlag |
publishDate |
2001 |
url |
https://authors.library.caltech.edu/44971/ https://resolver.caltech.edu/CaltechAUTHORS:20140416-090645328 |
long_lat |
ENVELOPE(27.000,27.000,-47.000,-47.000) |
geographic |
Antarctic The Antarctic Agulhas Basin |
geographic_facet |
Antarctic The Antarctic Agulhas Basin |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_relation |
Marks, K. M. and Stock, J. M. (2001) Evolution of the Malvinas Plate South of Africa. Marine Geophysical Researches, 22 (4). pp. 289-302. ISSN 0025-3235. doi:10.1023/A:1014638325616. https://resolver.caltech.edu/CaltechAUTHORS:20140416-090645328 <https://resolver.caltech.edu/CaltechAUTHORS:20140416-090645328> |
op_doi |
https://doi.org/10.1023/A:1014638325616 |
_version_ |
1766276372591804416 |