Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals
The elongated distribution of virtual geomagnetic poles (VGPs) of South American Jurassic units has been interpreted as reflecting: 1) the behavior of the Earth's magnetic field (EMF), and 2) apparent polar shift of the South American plate before the breakup of Gondwana. New paleomagnetic data...
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1992
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v6_n4_p253_Vizan http://hdl.handle.net/20.500.12110/paper_08959811_v6_n4_p253_Vizan |
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paper:paper_08959811_v6_n4_p253_Vizan2023-06-08T15:48:53Z Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals Vizan, Haroldo Mena, Mabel Vilas, Juan Francisco A. geoid Jurassic magnetic reversal palaeomagnetism Pangaea virtual geomagnetic pole South America The elongated distribution of virtual geomagnetic poles (VGPs) of South American Jurassic units has been interpreted as reflecting: 1) the behavior of the Earth's magnetic field (EMF), and 2) apparent polar shift of the South American plate before the breakup of Gondwana. New paleomagnetic data do not support the latter. We analyze these Jurassic VGPs together with those of other Pangean continents, considering a model based on the following assumptions: 1) Pangea was assembled over the present African-Atlantic geoid high; 2) the hotspot framework has not been significantly deformed over the last 200 Ma; 3) the present geoid matches the present topography of the core mantle boundary (CMB); 4) the overall topography of the CMB remains unchanged for long periods of time. We plotted Jurassic VGPs of Pangean continents, previously returned to a fixed-hotspot framework, on a map of the present topography of the CMB. The VGPs seem to follow the trend of regions of increased CMB seismic velocities. When a polarity reversal was registered by a Jurassic unit, the path of the VGPs was channeled on zones that have been observed in translational paths for the last 10 Ma. © 1993. Fil:Vizán, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Mena, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Vilas, J.F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1992 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v6_n4_p253_Vizan http://hdl.handle.net/20.500.12110/paper_08959811_v6_n4_p253_Vizan |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
geoid Jurassic magnetic reversal palaeomagnetism Pangaea virtual geomagnetic pole South America |
spellingShingle |
geoid Jurassic magnetic reversal palaeomagnetism Pangaea virtual geomagnetic pole South America Vizan, Haroldo Mena, Mabel Vilas, Juan Francisco A. Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals |
topic_facet |
geoid Jurassic magnetic reversal palaeomagnetism Pangaea virtual geomagnetic pole South America |
description |
The elongated distribution of virtual geomagnetic poles (VGPs) of South American Jurassic units has been interpreted as reflecting: 1) the behavior of the Earth's magnetic field (EMF), and 2) apparent polar shift of the South American plate before the breakup of Gondwana. New paleomagnetic data do not support the latter. We analyze these Jurassic VGPs together with those of other Pangean continents, considering a model based on the following assumptions: 1) Pangea was assembled over the present African-Atlantic geoid high; 2) the hotspot framework has not been significantly deformed over the last 200 Ma; 3) the present geoid matches the present topography of the core mantle boundary (CMB); 4) the overall topography of the CMB remains unchanged for long periods of time. We plotted Jurassic VGPs of Pangean continents, previously returned to a fixed-hotspot framework, on a map of the present topography of the CMB. The VGPs seem to follow the trend of regions of increased CMB seismic velocities. When a polarity reversal was registered by a Jurassic unit, the path of the VGPs was channeled on zones that have been observed in translational paths for the last 10 Ma. © 1993. |
author |
Vizan, Haroldo Mena, Mabel Vilas, Juan Francisco A. |
author_facet |
Vizan, Haroldo Mena, Mabel Vilas, Juan Francisco A. |
author_sort |
Vizan, Haroldo |
title |
Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals |
title_short |
Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals |
title_full |
Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals |
title_fullStr |
Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals |
title_full_unstemmed |
Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals |
title_sort |
pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals |
publishDate |
1992 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v6_n4_p253_Vizan http://hdl.handle.net/20.500.12110/paper_08959811_v6_n4_p253_Vizan |
work_keys_str_mv |
AT vizanharoldo pangeathegeoidandthepathsofvirtualgeomagneticpolesduringpolarityreversals AT menamabel pangeathegeoidandthepathsofvirtualgeomagneticpolesduringpolarityreversals AT vilasjuanfranciscoa pangeathegeoidandthepathsofvirtualgeomagneticpolesduringpolarityreversals |
_version_ |
1768542182771261440 |