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

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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Detalles Bibliográficos
Autores principales: Geuna, Silvana Evangelina, Vizan, Haroldo
Publicado: 1998
Materias:
Argentina
Early Cretaceous
Palaeomagnetism
South America
apparent polar wander path
Cretaceous
paleomagnetism
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0956540X_v135_n3_p1085_Geuna
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
id paper:paper_0956540X_v135_n3_p1085_Geuna
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spelling paper:paper_0956540X_v135_n3_p1085_Geuna2023-06-08T15:56:09Z New Early Cretaceous palaeomagnetic pole from Cordoba Province (Argentina): Revision of previous studies and implications for the South American database Geuna, Silvana Evangelina Vizan, Haroldo 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 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0956540X_v135_n3_p1085_Geuna 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)
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, Silvana Evangelina
Vizan, Haroldo
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.
author Geuna, Silvana Evangelina
Vizan, Haroldo
author_facet Geuna, Silvana Evangelina
Vizan, Haroldo
author_sort Geuna, Silvana Evangelina
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 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0956540X_v135_n3_p1085_Geuna
http://hdl.handle.net/20.500.12110/paper_0956540X_v135_n3_p1085_Geuna
work_keys_str_mv AT geunasilvanaevangelina newearlycretaceouspalaeomagneticpolefromcordobaprovinceargentinarevisionofpreviousstudiesandimplicationsforthesouthamericandatabase
AT vizanharoldo newearlycretaceouspalaeomagneticpolefromcordobaprovinceargentinarevisionofpreviousstudiesandimplicationsforthesouthamericandatabase
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