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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Autores principales:	Vizán, H., Mena, M., Vilas, J.F.
Formato:	JOUR
Materias:	geoid Jurassic magnetic reversal palaeomagnetism Pangaea virtual geomagnetic pole South America
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_08959811_v6_n4_p253_Vizan
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_08959811_v6_n4_p253_Vizan
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spelling	todo:paper_08959811_v6_n4_p253_Vizan2023-10-03T15:43:22Z Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals Vizán, H. Mena, M. Vilas, J.F. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar 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 Vizán, H. Mena, M. Vilas, J.F. 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.
format	JOUR
author	Vizán, H. Mena, M. Vilas, J.F.
author_facet	Vizán, H. Mena, M. Vilas, J.F.
author_sort	Vizán, H.
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
url	http://hdl.handle.net/20.500.12110/paper_08959811_v6_n4_p253_Vizan
work_keys_str_mv	AT vizanh pangeathegeoidandthepathsofvirtualgeomagneticpolesduringpolarityreversals AT menam pangeathegeoidandthepathsofvirtualgeomagneticpolesduringpolarityreversals AT vilasjf pangeathegeoidandthepathsofvirtualgeomagneticpolesduringpolarityreversals
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Pangea, the geoid, and the paths of virtual geomagnetic poles during polarity reversals

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