A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)

Available apparent polar wander (APW) paths for the 200 Ma configuration of Pangea, just prior to the opening of the Central Atlantic Ocean, differ as much as 10o in arc length. Here, we add new data from northwest Africa for this time, obtained from the northeasttrending Foum-Zguid and Ighrem dykes...

Descripción completa

Detalles Bibliográficos
Autores: Palencia Ortas, Alicia, Ruiz Martínez, Vicente Carlos, Villalain, J.J., Osete López, María Luisa, Vegas Martínez, Ramón, Touil, A., Hafid, A., McIntosh, G., Hinsbergen, D.J.J. van, Torsvik, T. H.
Tipo de recurso: artículo
Fecha de publicación:2011
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/44941
Acceso en línea:https://hdl.handle.net/20.500.14352/44941
Access Level:acceso abierto
Palabra clave:550.38(6)
551.24(6)
Plate motions
Palaeomagnetic secular variation
Palaeomagnetism applied to tectonics
Rock and mineral magnetism
Cratons
Africa
Geodinámica
2507 Geofísica
id ES_a06d08cc7a0633e694313e1199bc3aaa
oai_identifier_str oai:docta.ucm.es:20.500.14352/44941
network_acronym_str ES
network_name_str España
repository_id_str
spelling A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)Palencia Ortas, AliciaRuiz Martínez, Vicente CarlosVillalain, J.J.Osete López, María LuisaVegas Martínez, RamónTouil, A.Hafid, A.McIntosh, G.Hinsbergen, D.J.J. vanTorsvik, T. H.550.38(6)551.24(6)Plate motionsPalaeomagnetic secular variationPalaeomagnetism applied to tectonicsRock and mineral magnetismCratonsAfricaGeodinámica2507 GeofísicaAvailable apparent polar wander (APW) paths for the 200 Ma configuration of Pangea, just prior to the opening of the Central Atlantic Ocean, differ as much as 10o in arc length. Here, we add new data from northwest Africa for this time, obtained from the northeasttrending Foum-Zguid and Ighrem dykes (ca. 200 Ma). These dykes form part of the northern domain of the Central Atlantic Magmatic Province (CAMP), and crosscut the Anti-Atlas Ranges in Morocco, and compositionally correspond to quartz-normative tholeiites intruded in continental lithosphere shortly before the opening of the Central Atlantic Ocean. The Foum-Zguid dyke has been intensively studied, whereas the Ighrem dyke has received less scientific focus. We sampled both dykes for paleomagnetic investigation along 100 km of each dyke (12 sites for Foum-Zguid and 11 for Ighrem, 188 samples included in the final analyses). Rock magnetic experiments indicate a mixture of multidomain and single-domain magnetite and/or low-Ti titanomagnetite particles as the principal remanence carriers. In both dykes, the primary nature of the characteristic remanent magnetization is supported by positive contact tests, related to Fe-metasomatism or baked overprints of the corresponding sedimentary country rocks. The directions of the characteristic magnetization exhibit exclusively normal polarity. Site-mean virtual geomagnetic poles are differently grouped in each dyke, suggesting distinct geomagnetic secular variation records. The Foum-Zguid paleomagnetic pole (N = 12, PLat = 67.9◦N, PLon = 247.9◦E, κ = 125, A95 = 3.9◦) plots close to that of Ighrem (N = 11, PLat = 78.4◦N, PLon = 238.2◦E, κ = 47, A95 = 6.7◦), confirming those mineralogical and geochemical evidences supporting that they represent dissimilar magmatic stages. Virtual geomagnetic poles dispersion from both dykes (S = 10.5◦13.0◦ 8.1◦ ) is in line with those obtained from recent studies of a CAMP-related dyke in Iberia and results from CAMP lavas in the Argana basin. These three new estimates of paleosecular variation at low latitudes around the Triassic–Jurassic boundary are concordant with a recently proposed dispersion curve for the Jurassic but suggest a slightly lower geomagnetic scatter than considered so far. After combining results from both dykes, the resulting paleomagnetic pole (PLat = 73.0◦N, PLon = 244.7◦E, N = 23, κ = 55, A95 = 4.1◦) is statistically compared with existing and coeval African paleopoles, and with global synthetic 200 Ma running mean poles in northwest Africa coordinates.Oxford University PressUniversidad Complutense de Madrid20112011-01-0120112011-01-01journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/44941reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/449412026-06-02T12:44:21Z
dc.title.none.fl_str_mv A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
title A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
spellingShingle A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
Palencia Ortas, Alicia
550.38(6)
551.24(6)
Plate motions
Palaeomagnetic secular variation
Palaeomagnetism applied to tectonics
Rock and mineral magnetism
Cratons
Africa
Geodinámica
2507 Geofísica
title_short A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
title_full A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
title_fullStr A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
title_full_unstemmed A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
title_sort A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)
dc.creator.none.fl_str_mv Palencia Ortas, Alicia
Ruiz Martínez, Vicente Carlos
Villalain, J.J.
Osete López, María Luisa
Vegas Martínez, Ramón
Touil, A.
Hafid, A.
McIntosh, G.
Hinsbergen, D.J.J. van
Torsvik, T. H.
author Palencia Ortas, Alicia
author_facet Palencia Ortas, Alicia
Ruiz Martínez, Vicente Carlos
Villalain, J.J.
Osete López, María Luisa
Vegas Martínez, Ramón
Touil, A.
Hafid, A.
McIntosh, G.
Hinsbergen, D.J.J. van
Torsvik, T. H.
author_role author
author2 Ruiz Martínez, Vicente Carlos
Villalain, J.J.
Osete López, María Luisa
Vegas Martínez, Ramón
Touil, A.
Hafid, A.
McIntosh, G.
Hinsbergen, D.J.J. van
Torsvik, T. H.
author2_role author
author
author
author
author
author
author
author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 550.38(6)
551.24(6)
Plate motions
Palaeomagnetic secular variation
Palaeomagnetism applied to tectonics
Rock and mineral magnetism
Cratons
Africa
Geodinámica
2507 Geofísica
topic 550.38(6)
551.24(6)
Plate motions
Palaeomagnetic secular variation
Palaeomagnetism applied to tectonics
Rock and mineral magnetism
Cratons
Africa
Geodinámica
2507 Geofísica
description Available apparent polar wander (APW) paths for the 200 Ma configuration of Pangea, just prior to the opening of the Central Atlantic Ocean, differ as much as 10o in arc length. Here, we add new data from northwest Africa for this time, obtained from the northeasttrending Foum-Zguid and Ighrem dykes (ca. 200 Ma). These dykes form part of the northern domain of the Central Atlantic Magmatic Province (CAMP), and crosscut the Anti-Atlas Ranges in Morocco, and compositionally correspond to quartz-normative tholeiites intruded in continental lithosphere shortly before the opening of the Central Atlantic Ocean. The Foum-Zguid dyke has been intensively studied, whereas the Ighrem dyke has received less scientific focus. We sampled both dykes for paleomagnetic investigation along 100 km of each dyke (12 sites for Foum-Zguid and 11 for Ighrem, 188 samples included in the final analyses). Rock magnetic experiments indicate a mixture of multidomain and single-domain magnetite and/or low-Ti titanomagnetite particles as the principal remanence carriers. In both dykes, the primary nature of the characteristic remanent magnetization is supported by positive contact tests, related to Fe-metasomatism or baked overprints of the corresponding sedimentary country rocks. The directions of the characteristic magnetization exhibit exclusively normal polarity. Site-mean virtual geomagnetic poles are differently grouped in each dyke, suggesting distinct geomagnetic secular variation records. The Foum-Zguid paleomagnetic pole (N = 12, PLat = 67.9◦N, PLon = 247.9◦E, κ = 125, A95 = 3.9◦) plots close to that of Ighrem (N = 11, PLat = 78.4◦N, PLon = 238.2◦E, κ = 47, A95 = 6.7◦), confirming those mineralogical and geochemical evidences supporting that they represent dissimilar magmatic stages. Virtual geomagnetic poles dispersion from both dykes (S = 10.5◦13.0◦ 8.1◦ ) is in line with those obtained from recent studies of a CAMP-related dyke in Iberia and results from CAMP lavas in the Argana basin. These three new estimates of paleosecular variation at low latitudes around the Triassic–Jurassic boundary are concordant with a recently proposed dispersion curve for the Jurassic but suggest a slightly lower geomagnetic scatter than considered so far. After combining results from both dykes, the resulting paleomagnetic pole (PLat = 73.0◦N, PLon = 244.7◦E, N = 23, κ = 55, A95 = 4.1◦) is statistically compared with existing and coeval African paleopoles, and with global synthetic 200 Ma running mean poles in northwest Africa coordinates.
publishDate 2011
dc.date.none.fl_str_mv 2011
2011-01-01
2011
2011-01-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/44941
url https://hdl.handle.net/20.500.14352/44941
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Oxford University Press
publisher.none.fl_str_mv Oxford University Press
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869415010063613952
score 15,301603

Similares en LA Referencia