Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina

Autores
Rapalini, Augusto Ernesto; Lopez, Monica Graciela
Año de publicación
2000
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Jurassic volcanism in Patagonia is widespread. Although associated dyke swarms are conspicuous, they have been almost neglected in previous geologic studies of this region. Radiometric, paleomagnetic and magnetic anisotropy studies are reported from a Middle Jurassic basic to intermediate dyke swarm exposed in the Sierra de Mamil Choique (Western Patagonia) in an area of over 350 km2. Two whole-rock K/Ar determinations indicate that these dykes were intruded at around 170 Ma. An anisotropy of magnetic susceptibility (AMS) study on 15 dykes (74 block samples) shows that they carry different kinds of magnetic fabric (both normal and inverse), apparently governed by compositional differences. A paleomagnetic study of these samples suggests that Ti-poor titanomagnetite is the probable carrier to the characteristic remanence. Mean site characteristic directions pass a reversal test (grade C). A paleomagnetic pole, computed by averaging VGPs from each individual dyke, is situated at 70.2°S, 190.4°E (N = 13, α95 = 9.7°), not substantially apart from other Middle Jurassic poles from South America. Further refinement of the Jurassic South American apparent polar wander path is needed to establish whether or not the Mamil Choique dykes were affected by a small tectonic rotation.
Fil: Rapalini, Augusto Ernesto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Instituto de Geofísica "Daniel Valencio"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina
Fil: Lopez, Monica Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotópica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; Argentina
Materia
Dyke Swarms
Jurassic
Magnetic Fabric
Paleomagnetism
Patagonia
South America
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/71724
Acceder
id CONICETDig_69b5b8c3705bda068d089876f094bf59
oai_identifier_str oai:ri.conicet.gov.ar:11336/71724
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, ArgentinaRapalini, Augusto ErnestoLopez, Monica GracielaDyke SwarmsJurassicMagnetic FabricPaleomagnetismPatagoniaSouth Americahttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Jurassic volcanism in Patagonia is widespread. Although associated dyke swarms are conspicuous, they have been almost neglected in previous geologic studies of this region. Radiometric, paleomagnetic and magnetic anisotropy studies are reported from a Middle Jurassic basic to intermediate dyke swarm exposed in the Sierra de Mamil Choique (Western Patagonia) in an area of over 350 km2. Two whole-rock K/Ar determinations indicate that these dykes were intruded at around 170 Ma. An anisotropy of magnetic susceptibility (AMS) study on 15 dykes (74 block samples) shows that they carry different kinds of magnetic fabric (both normal and inverse), apparently governed by compositional differences. A paleomagnetic study of these samples suggests that Ti-poor titanomagnetite is the probable carrier to the characteristic remanence. Mean site characteristic directions pass a reversal test (grade C). A paleomagnetic pole, computed by averaging VGPs from each individual dyke, is situated at 70.2°S, 190.4°E (N = 13, α95 = 9.7°), not substantially apart from other Middle Jurassic poles from South America. Further refinement of the Jurassic South American apparent polar wander path is needed to establish whether or not the Mamil Choique dykes were affected by a small tectonic rotation.Fil: Rapalini, Augusto Ernesto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Instituto de Geofísica "Daniel Valencio"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Lopez, Monica Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotópica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaElsevier Science2000-06info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/71724Rapalini, Augusto Ernesto; Lopez, Monica Graciela; Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina; Elsevier Science; Physics of the Earth and Planetary Interiors; 120; 1; 6-2000; 11-270031-9201CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0031920100001400info:eu-repo/semantics/altIdentifier/doi/10.1016/S0031-9201(00)00140-0info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T14:30:25Zoai:ri.conicet.gov.ar:11336/71724instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-15 14:30:25.521CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina
title Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina
spellingShingle Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina
Rapalini, Augusto Ernesto
Dyke Swarms
Jurassic
Magnetic Fabric
Paleomagnetism
Patagonia
South America
title_short Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina
title_full Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina
title_fullStr Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina
title_full_unstemmed Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina
title_sort Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina
dc.creator.none.fl_str_mv Rapalini, Augusto Ernesto
Lopez, Monica Graciela
author Rapalini, Augusto Ernesto
author_facet Rapalini, Augusto Ernesto
Lopez, Monica Graciela
author_role author
author2 Lopez, Monica Graciela
author2_role author
dc.subject.none.fl_str_mv Dyke Swarms
Jurassic
Magnetic Fabric
Paleomagnetism
Patagonia
South America
topic Dyke Swarms
Jurassic
Magnetic Fabric
Paleomagnetism
Patagonia
South America
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Jurassic volcanism in Patagonia is widespread. Although associated dyke swarms are conspicuous, they have been almost neglected in previous geologic studies of this region. Radiometric, paleomagnetic and magnetic anisotropy studies are reported from a Middle Jurassic basic to intermediate dyke swarm exposed in the Sierra de Mamil Choique (Western Patagonia) in an area of over 350 km2. Two whole-rock K/Ar determinations indicate that these dykes were intruded at around 170 Ma. An anisotropy of magnetic susceptibility (AMS) study on 15 dykes (74 block samples) shows that they carry different kinds of magnetic fabric (both normal and inverse), apparently governed by compositional differences. A paleomagnetic study of these samples suggests that Ti-poor titanomagnetite is the probable carrier to the characteristic remanence. Mean site characteristic directions pass a reversal test (grade C). A paleomagnetic pole, computed by averaging VGPs from each individual dyke, is situated at 70.2°S, 190.4°E (N = 13, α95 = 9.7°), not substantially apart from other Middle Jurassic poles from South America. Further refinement of the Jurassic South American apparent polar wander path is needed to establish whether or not the Mamil Choique dykes were affected by a small tectonic rotation.
Fil: Rapalini, Augusto Ernesto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Instituto de Geofísica "Daniel Valencio"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina
Fil: Lopez, Monica Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotópica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; Argentina
description Jurassic volcanism in Patagonia is widespread. Although associated dyke swarms are conspicuous, they have been almost neglected in previous geologic studies of this region. Radiometric, paleomagnetic and magnetic anisotropy studies are reported from a Middle Jurassic basic to intermediate dyke swarm exposed in the Sierra de Mamil Choique (Western Patagonia) in an area of over 350 km2. Two whole-rock K/Ar determinations indicate that these dykes were intruded at around 170 Ma. An anisotropy of magnetic susceptibility (AMS) study on 15 dykes (74 block samples) shows that they carry different kinds of magnetic fabric (both normal and inverse), apparently governed by compositional differences. A paleomagnetic study of these samples suggests that Ti-poor titanomagnetite is the probable carrier to the characteristic remanence. Mean site characteristic directions pass a reversal test (grade C). A paleomagnetic pole, computed by averaging VGPs from each individual dyke, is situated at 70.2°S, 190.4°E (N = 13, α95 = 9.7°), not substantially apart from other Middle Jurassic poles from South America. Further refinement of the Jurassic South American apparent polar wander path is needed to establish whether or not the Mamil Choique dykes were affected by a small tectonic rotation.
publishDate 2000
dc.date.none.fl_str_mv 2000-06
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/71724
Rapalini, Augusto Ernesto; Lopez, Monica Graciela; Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina; Elsevier Science; Physics of the Earth and Planetary Interiors; 120; 1; 6-2000; 11-27
0031-9201
CONICET Digital
CONICET
url http://hdl.handle.net/11336/71724
identifier_str_mv Rapalini, Augusto Ernesto; Lopez, Monica Graciela; Paleomagnetism and magnetic fabric of Middle Jurassic dykes from Western Patagonia, Argentina; Elsevier Science; Physics of the Earth and Planetary Interiors; 120; 1; 6-2000; 11-27
0031-9201
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0031920100001400
info:eu-repo/semantics/altIdentifier/doi/10.1016/S0031-9201(00)00140-0
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
_version_ 1846082780898787328
score 13.22299

Publicaciones similares