New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database

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A continental sequence of red beds and interbedded basaltic layers crops out in the Sierra Chica of Cordoba Province, Argentina (31.5°S, 64.4°W). This succession was deposited in a half-graben basin during the Early Cretaceous. We have carried out a palaeomagnetic survey on outcrops of this basin (1...

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Autores principales: Geuna, S.E., Vizán, H.
Formato: Artículo publishedVersion
Lenguaje:Inglés
Publicado: 1998
Materias:
Argentina
Early Cretaceous
Palaeomagnetism
South America
apparent polar wander path
Cretaceous
paleomagnetism
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0956540X_v135_n3_p1085_Geuna
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling paperaa:paper_0956540X_v135_n3_p1085_Geuna2023-06-12T16:48:41Z New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database Geophys. J. Int. 1998;135(3):1085-1100 Geuna, S.E. Vizán, H. Argentina Early Cretaceous Palaeomagnetism South America apparent polar wander path Cretaceous paleomagnetism South America A continental sequence of red beds and interbedded basaltic layers crops out in the Sierra Chica of Cordoba Province, Argentina (31.5°S, 64.4°W). This succession was deposited in a half-graben basin during the Early Cretaceous. We have carried out a palaeomagnetic survey on outcrops of this basin (147 sites in seven localities). From an analysis of IRM acquisition curves and detailed demagnetization behaviour, three different magnetic components are identified in the volcanic rocks: components A, B and X are carried by single- or pseudo-single-domain (titano) magnetite, haematite and multidomain magnetite, respectively. Component A is interpreted as a primary component of magnetization because it passes conglomerate, contact, tilt and reversal tests. The carrier of the primary magnetization, fine-grained (titano) magnetite, is present in basalts with a high degree of deuteric oxidation. This kind of oxidation is interpreted to have occurred during cooling. Components B and X are discarded because they are interpreted as recent magnetizations. In the sedimentary rocks, haematite and magnetite are identified as the carriers of remanence. Both minerals carry the same component, which passes a reversal test. The calculated palaeomagnetic pole, based on 55 sites, is Lat. 86.0°S, Long. 75.9°E (A95=3.3, K=35). This palaeomagnetic pole supersedes four with anomalous positions reported in previous papers. Fil:Geuna, S.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Vizán, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1998 info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion application/pdf eng info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0956540X_v135_n3_p1085_Geuna
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
language Inglés
orig_language_str_mv eng
topic Argentina
Early Cretaceous
Palaeomagnetism
South America
apparent polar wander path
Cretaceous
paleomagnetism
South America
spellingShingle Argentina
Early Cretaceous
Palaeomagnetism
South America
apparent polar wander path
Cretaceous
paleomagnetism
South America
Geuna, S.E.
Vizán, H.
New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database
topic_facet Argentina
Early Cretaceous
Palaeomagnetism
South America
apparent polar wander path
Cretaceous
paleomagnetism
South America
description A continental sequence of red beds and interbedded basaltic layers crops out in the Sierra Chica of Cordoba Province, Argentina (31.5°S, 64.4°W). This succession was deposited in a half-graben basin during the Early Cretaceous. We have carried out a palaeomagnetic survey on outcrops of this basin (147 sites in seven localities). From an analysis of IRM acquisition curves and detailed demagnetization behaviour, three different magnetic components are identified in the volcanic rocks: components A, B and X are carried by single- or pseudo-single-domain (titano) magnetite, haematite and multidomain magnetite, respectively. Component A is interpreted as a primary component of magnetization because it passes conglomerate, contact, tilt and reversal tests. The carrier of the primary magnetization, fine-grained (titano) magnetite, is present in basalts with a high degree of deuteric oxidation. This kind of oxidation is interpreted to have occurred during cooling. Components B and X are discarded because they are interpreted as recent magnetizations. In the sedimentary rocks, haematite and magnetite are identified as the carriers of remanence. Both minerals carry the same component, which passes a reversal test. The calculated palaeomagnetic pole, based on 55 sites, is Lat. 86.0°S, Long. 75.9°E (A95=3.3, K=35). This palaeomagnetic pole supersedes four with anomalous positions reported in previous papers.
format Artículo
Artículo
publishedVersion
author Geuna, S.E.
Vizán, H.
author_facet Geuna, S.E.
Vizán, H.
author_sort Geuna, S.E.
title New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database
title_short New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database
title_full New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database
title_fullStr New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database
title_full_unstemmed New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database
title_sort new early cretaceous palaeomagnetic pole from cordoba province (argentina): revision of previous studies and implications for the south american database
publishDate 1998
url http://hdl.handle.net/20.500.12110/paper_0956540X_v135_n3_p1085_Geuna
work_keys_str_mv AT geunase newearlycretaceouspalaeomagneticpolefromcordobaprovinceargentinarevisionofpreviousstudiesandimplicationsforthesouthamericandatabase
AT vizanh newearlycretaceouspalaeomagneticpolefromcordobaprovinceargentinarevisionofpreviousstudiesandimplicationsforthesouthamericandatabase
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