Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America

The palaeomagnetic sudy was carried out in five sections cropping out in the Neuquén Basin, which are made up of hundreds metres-thick of ammonite-bearing sedimentary and subordinately, volcanic rocks of Early Jurassic age. These sections are located in the northern part of the basin along the Atuel...

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Detalhes bibliográficos
Autor: Iglesia Llanos, M.P.
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2009
País:Argentina
Recursos:Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
Repositório:Biblioteca Digital (UBA-FCEN)
Idioma:inglês
OAI Identifier:paperaa:paper_00044822_v65_n2_p387_IglesiaLlanos
Acesso em linha:http://hdl.handle.net/20.500.12110/paper_00044822_v65_n2_p387_IglesiaLlanos
Access Level:Acceso aberto
Palavra-chave:Ammonites
Jurassic
Neuquén Basin
Palaeogeography
Palaeomagnetism
ammonite
apparent polar wander path
geomagnetism
magnetic reversal
magnetostratigraphy
paleogeography
paleomagnetism
petrography
Southern Hemisphere
stratigraphy
titanomagnetite
Argentina
Neuquen Basin
Ammonoidea
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spelling Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America Iglesia Llanos, M.P.AmmonitesJurassicNeuquén BasinPalaeogeographyPalaeomagnetismammoniteapparent polar wander pathgeomagnetismJurassicmagnetic reversalmagnetostratigraphypaleogeographypaleomagnetismpetrographySouthern HemispherestratigraphytitanomagnetiteArgentinaNeuquen BasinAmmonoideaThe palaeomagnetic sudy was carried out in five sections cropping out in the Neuquén Basin, which are made up of hundreds metres-thick of ammonite-bearing sedimentary and subordinately, volcanic rocks of Early Jurassic age. These sections are located in the northern part of the basin along the Atuel river (Hettangian to Toarcian), and the central part (Pliensbachian to Toarcian) of the basin. From paleomagnetic and petrographical studies two magnetic components carried by titanomagnetites were recognised, one soft bearing a direction that coincides with the local present-day field, and another harder interpreted as the original jurassic according to the palaeomagnetic field tests. Based on the polarities succession isolated in the five sections, a composite magnetostratigraphic scale was elaborated, which is the first of this age in the Southern Hemisphere. Eleven dominantly reversed (JR1 to JR11) and 12 dominantly normal (JN1 to JN12) polarity zones were identified, in relation with 19 ammonite zones from the Andean Region, which were in turn correlated with the international standard geomagnetic time scale. The good fit between the two scales allowed to date some stratigraphic levels with no diagnotic fossils, such as the Sinemurian-Pliensbachian boundary at Puesto Araya, and the Pliensbachian-Toarcian limit at Rapajalo. On the other hand, two palaeomagnetic poles were calculated, one for the Hettangian-Sinemurian (223°E, 51°S, A95= 6°, N = 25) and another for the Pliensbachian-Toarcian (67°E, 74°S, A95= 5°, N = 52). These poles, combined with others selected from the literature, led to the construction of a new apparent polar wander (APW) path of South America for the Late Triassic-Jurassic time interval, which turned out to be dissimilar from previous curves placing the continent in a stationary latitudinal position during most of the Mesozoic. The resultant APW path suggests that South America would have rotated clockwise while it was moving northward. The same shape and chronology is observed in the jurassic path of Eurasia. The latitudinal shifts derived from the palaeomagnetic data are supported by diverse marine faunas from both the southern and northern hemispheres.Fil:Iglesia Llanos, M.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.2009info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://hdl.handle.net/20.500.12110/paper_00044822_v65_n2_p387_IglesiaLlanosRev. Asoc. Geol. Argent. 2009;65(2):387-399reponame:Biblioteca Digital (UBA-FCEN)instname:Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturalesinstacron:UBA-FCENenginfo:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/2.5/ar2024-05-10T10:42:44Zpaperaa:paper_00044822_v65_n2_p387_IglesiaLlanosInstitucionalhttps://digital.bl.fcen.uba.ar/Universidad públicaNo correspondehttps://digital.bl.fcen.uba.ar/cgi-bin/oaiserver.cgiana@bl.fcen.uba.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:18962024-05-10 10:42:45.381Biblioteca Digital (UBA-FCEN) - Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturalesfalse
dc.title.none.fl_str_mv Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America
title Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America
spellingShingle Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America
Iglesia Llanos, M.P.
Ammonites
Jurassic
Neuquén Basin
Palaeogeography
Palaeomagnetism
ammonite
apparent polar wander path
geomagnetism
Jurassic
magnetic reversal
magnetostratigraphy
paleogeography
paleomagnetism
petrography
Southern Hemisphere
stratigraphy
titanomagnetite
Argentina
Neuquen Basin
Ammonoidea
title_short Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America
title_full Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America
title_fullStr Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America
title_full_unstemmed Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America
title_sort Palaeomagnetic study of marine Jurassic strata from the Neuquén Basin: Magnetostratigraphic correlation of the Lower Jurassic and a new apparent polar wander path for South America
dc.creator.none.fl_str_mv Iglesia Llanos, M.P.
author Iglesia Llanos, M.P.
author_facet Iglesia Llanos, M.P.
author_role author
dc.subject.none.fl_str_mv Ammonites
Jurassic
Neuquén Basin
Palaeogeography
Palaeomagnetism
ammonite
apparent polar wander path
geomagnetism
Jurassic
magnetic reversal
magnetostratigraphy
paleogeography
paleomagnetism
petrography
Southern Hemisphere
stratigraphy
titanomagnetite
Argentina
Neuquen Basin
Ammonoidea
topic Ammonites
Jurassic
Neuquén Basin
Palaeogeography
Palaeomagnetism
ammonite
apparent polar wander path
geomagnetism
Jurassic
magnetic reversal
magnetostratigraphy
paleogeography
paleomagnetism
petrography
Southern Hemisphere
stratigraphy
titanomagnetite
Argentina
Neuquen Basin
Ammonoidea
description The palaeomagnetic sudy was carried out in five sections cropping out in the Neuquén Basin, which are made up of hundreds metres-thick of ammonite-bearing sedimentary and subordinately, volcanic rocks of Early Jurassic age. These sections are located in the northern part of the basin along the Atuel river (Hettangian to Toarcian), and the central part (Pliensbachian to Toarcian) of the basin. From paleomagnetic and petrographical studies two magnetic components carried by titanomagnetites were recognised, one soft bearing a direction that coincides with the local present-day field, and another harder interpreted as the original jurassic according to the palaeomagnetic field tests. Based on the polarities succession isolated in the five sections, a composite magnetostratigraphic scale was elaborated, which is the first of this age in the Southern Hemisphere. Eleven dominantly reversed (JR1 to JR11) and 12 dominantly normal (JN1 to JN12) polarity zones were identified, in relation with 19 ammonite zones from the Andean Region, which were in turn correlated with the international standard geomagnetic time scale. The good fit between the two scales allowed to date some stratigraphic levels with no diagnotic fossils, such as the Sinemurian-Pliensbachian boundary at Puesto Araya, and the Pliensbachian-Toarcian limit at Rapajalo. On the other hand, two palaeomagnetic poles were calculated, one for the Hettangian-Sinemurian (223°E, 51°S, A95= 6°, N = 25) and another for the Pliensbachian-Toarcian (67°E, 74°S, A95= 5°, N = 52). These poles, combined with others selected from the literature, led to the construction of a new apparent polar wander (APW) path of South America for the Late Triassic-Jurassic time interval, which turned out to be dissimilar from previous curves placing the continent in a stationary latitudinal position during most of the Mesozoic. The resultant APW path suggests that South America would have rotated clockwise while it was moving northward. The same shape and chronology is observed in the jurassic path of Eurasia. The latitudinal shifts derived from the palaeomagnetic data are supported by diverse marine faunas from both the southern and northern hemispheres.
publishDate 2009
dc.date.none.fl_str_mv 2009
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/20.500.12110/paper_00044822_v65_n2_p387_IglesiaLlanos
url http://hdl.handle.net/20.500.12110/paper_00044822_v65_n2_p387_IglesiaLlanos
dc.language.none.fl_str_mv eng
language eng
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/2.5/ar
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/2.5/ar
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv Rev. Asoc. Geol. Argent. 2009;65(2):387-399
reponame:Biblioteca Digital (UBA-FCEN)
instname:Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
instacron:UBA-FCEN
instname_str Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
instacron_str UBA-FCEN
institution UBA-FCEN
reponame_str Biblioteca Digital (UBA-FCEN)
collection Biblioteca Digital (UBA-FCEN)
repository.name.fl_str_mv Biblioteca Digital (UBA-FCEN) - Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
repository.mail.fl_str_mv ana@bl.fcen.uba.ar
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score 15,228081

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