New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana

Autores
Rapalini, Augusto Ernesto
Año de publicación
2006
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Major uncertainties remain on the precise kinematic and temporal aspects of Gondwana assembly. In order to provide new constraints on them, a paleomagnetic study was carried out on the Ediacaran succession of red claystones exposed in Sierra de los Barrientos (37.8°S, 59.0°W), Buenos Aires province, Argentina. This succesion belongs to the late Proterozoic-early Paleozoic sedimentary cover of the Rio de la Plata craton. Sixty-two oriented samples from 13 sites were submitted to standard stepwise demagnetization procedures yielding a characteristic remanence carried by hematite. A primary origin for the remanence is suggested by the apparent recording of secular variation along the stratigraphic column including a reversal of the earth magnetic field and an improvement in clustering of mean site directions after application of bedding corrections, although the latter is not statistically significant. Since the study samples show a significant anisotropy of magnetic susceptibility (AMS) degree (P up to 1.2) and an ellipsoid shape compatible with significant compaction during diagenesis, remanence inclination shallowing was investigated through oriented isothermal remanent magnetization (IRM) acquisition and demagnetization experiments. These permitted to confirm significant inclination shallowing and to compute a correction factor that was applied to the mean site directions producing a significantly further improvement in the statistical parameters. A paleomagnetic pole was computed for the Los Barrientos claystones at 15.1°S, 252.6°E, dp: 10.9°, dm: 14.2°. When rotated into a Gondwana framework, this new pole agrees with previous poles of ca. 550 Ma from several Gondwanan cratons, allowing the construction of a single APWP for the whole of Gondwana since that time, and suggesting that by ca. 550 Ma Gondwana was already assembled or in the final stages of that process.
Fil: Rapalini, Augusto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina
Materia
Gondwana
Paleomagnetism
Precambrian
Rio de La Plata Craton
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:11336/75878

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spelling New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for GondwanaRapalini, Augusto ErnestoGondwanaPaleomagnetismPrecambrianRio de La Plata CratonSouth Americahttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Major uncertainties remain on the precise kinematic and temporal aspects of Gondwana assembly. In order to provide new constraints on them, a paleomagnetic study was carried out on the Ediacaran succession of red claystones exposed in Sierra de los Barrientos (37.8°S, 59.0°W), Buenos Aires province, Argentina. This succesion belongs to the late Proterozoic-early Paleozoic sedimentary cover of the Rio de la Plata craton. Sixty-two oriented samples from 13 sites were submitted to standard stepwise demagnetization procedures yielding a characteristic remanence carried by hematite. A primary origin for the remanence is suggested by the apparent recording of secular variation along the stratigraphic column including a reversal of the earth magnetic field and an improvement in clustering of mean site directions after application of bedding corrections, although the latter is not statistically significant. Since the study samples show a significant anisotropy of magnetic susceptibility (AMS) degree (P up to 1.2) and an ellipsoid shape compatible with significant compaction during diagenesis, remanence inclination shallowing was investigated through oriented isothermal remanent magnetization (IRM) acquisition and demagnetization experiments. These permitted to confirm significant inclination shallowing and to compute a correction factor that was applied to the mean site directions producing a significantly further improvement in the statistical parameters. A paleomagnetic pole was computed for the Los Barrientos claystones at 15.1°S, 252.6°E, dp: 10.9°, dm: 14.2°. When rotated into a Gondwana framework, this new pole agrees with previous poles of ca. 550 Ma from several Gondwanan cratons, allowing the construction of a single APWP for the whole of Gondwana since that time, and suggesting that by ca. 550 Ma Gondwana was already assembled or in the final stages of that process.Fil: Rapalini, Augusto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaElsevier Science2006-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/75878Rapalini, Augusto Ernesto; New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana; Elsevier Science; Precambrian Research; 147; 3-4; 7-2006; 223-2330301-9268CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.precamres.2006.01.016info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0301926806000404info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:57:20Zoai:ri.conicet.gov.ar:11336/75878instacron: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:34982025-09-03 09:57:20.439CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana
title New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana
spellingShingle New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana
Rapalini, Augusto Ernesto
Gondwana
Paleomagnetism
Precambrian
Rio de La Plata Craton
South America
title_short New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana
title_full New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana
title_fullStr New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana
title_full_unstemmed New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana
title_sort New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana
dc.creator.none.fl_str_mv Rapalini, Augusto Ernesto
author Rapalini, Augusto Ernesto
author_facet Rapalini, Augusto Ernesto
author_role author
dc.subject.none.fl_str_mv Gondwana
Paleomagnetism
Precambrian
Rio de La Plata Craton
South America
topic Gondwana
Paleomagnetism
Precambrian
Rio de La Plata Craton
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 Major uncertainties remain on the precise kinematic and temporal aspects of Gondwana assembly. In order to provide new constraints on them, a paleomagnetic study was carried out on the Ediacaran succession of red claystones exposed in Sierra de los Barrientos (37.8°S, 59.0°W), Buenos Aires province, Argentina. This succesion belongs to the late Proterozoic-early Paleozoic sedimentary cover of the Rio de la Plata craton. Sixty-two oriented samples from 13 sites were submitted to standard stepwise demagnetization procedures yielding a characteristic remanence carried by hematite. A primary origin for the remanence is suggested by the apparent recording of secular variation along the stratigraphic column including a reversal of the earth magnetic field and an improvement in clustering of mean site directions after application of bedding corrections, although the latter is not statistically significant. Since the study samples show a significant anisotropy of magnetic susceptibility (AMS) degree (P up to 1.2) and an ellipsoid shape compatible with significant compaction during diagenesis, remanence inclination shallowing was investigated through oriented isothermal remanent magnetization (IRM) acquisition and demagnetization experiments. These permitted to confirm significant inclination shallowing and to compute a correction factor that was applied to the mean site directions producing a significantly further improvement in the statistical parameters. A paleomagnetic pole was computed for the Los Barrientos claystones at 15.1°S, 252.6°E, dp: 10.9°, dm: 14.2°. When rotated into a Gondwana framework, this new pole agrees with previous poles of ca. 550 Ma from several Gondwanan cratons, allowing the construction of a single APWP for the whole of Gondwana since that time, and suggesting that by ca. 550 Ma Gondwana was already assembled or in the final stages of that process.
Fil: Rapalini, Augusto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina
description Major uncertainties remain on the precise kinematic and temporal aspects of Gondwana assembly. In order to provide new constraints on them, a paleomagnetic study was carried out on the Ediacaran succession of red claystones exposed in Sierra de los Barrientos (37.8°S, 59.0°W), Buenos Aires province, Argentina. This succesion belongs to the late Proterozoic-early Paleozoic sedimentary cover of the Rio de la Plata craton. Sixty-two oriented samples from 13 sites were submitted to standard stepwise demagnetization procedures yielding a characteristic remanence carried by hematite. A primary origin for the remanence is suggested by the apparent recording of secular variation along the stratigraphic column including a reversal of the earth magnetic field and an improvement in clustering of mean site directions after application of bedding corrections, although the latter is not statistically significant. Since the study samples show a significant anisotropy of magnetic susceptibility (AMS) degree (P up to 1.2) and an ellipsoid shape compatible with significant compaction during diagenesis, remanence inclination shallowing was investigated through oriented isothermal remanent magnetization (IRM) acquisition and demagnetization experiments. These permitted to confirm significant inclination shallowing and to compute a correction factor that was applied to the mean site directions producing a significantly further improvement in the statistical parameters. A paleomagnetic pole was computed for the Los Barrientos claystones at 15.1°S, 252.6°E, dp: 10.9°, dm: 14.2°. When rotated into a Gondwana framework, this new pole agrees with previous poles of ca. 550 Ma from several Gondwanan cratons, allowing the construction of a single APWP for the whole of Gondwana since that time, and suggesting that by ca. 550 Ma Gondwana was already assembled or in the final stages of that process.
publishDate 2006
dc.date.none.fl_str_mv 2006-07
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/11336/75878
Rapalini, Augusto Ernesto; New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana; Elsevier Science; Precambrian Research; 147; 3-4; 7-2006; 223-233
0301-9268
CONICET Digital
CONICET
url http://hdl.handle.net/11336/75878
identifier_str_mv Rapalini, Augusto Ernesto; New late Proterozoic paleomagnetic pole for the Rio de la Plata craton: Implications for Gondwana; Elsevier Science; Precambrian Research; 147; 3-4; 7-2006; 223-233
0301-9268
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1016/j.precamres.2006.01.016
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0301926806000404
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
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
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repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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