Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera

The paper describes ubiquitous extensional structures developed in a passive margin of Ordovician age in the Argentine Precordillera. These extensional structures include normal faults and boudinaged sequences. In some places the boudinage reaches very high extension values, giving rise to block-in-...

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Autores principales:	Alonso, Jorge Luis, Ramos, Victor Alberto
Publicado:	2008
Materias:	Argentine Precordillera Extensional tectonics Gondwana Ordovician Submarine sliding
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1342937X_v13_n2_p204_Alonso http://hdl.handle.net/20.500.12110/paper_1342937X_v13_n2_p204_Alonso
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_1342937X_v13_n2_p204_Alonso
record_format	dspace
spelling	paper:paper_1342937X_v13_n2_p204_Alonso2023-06-08T16:10:28Z Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera Alonso, Jorge Luis Ramos, Victor Alberto Argentine Precordillera Extensional tectonics Gondwana Ordovician Submarine sliding The paper describes ubiquitous extensional structures developed in a passive margin of Ordovician age in the Argentine Precordillera. These extensional structures include normal faults and boudinaged sequences. In some places the boudinage reaches very high extension values, giving rise to block-in-matrix formations. Most of these extensional structures developed when sediments were not well lithified, as recorded by hydroplastic fractures, slump folds and pinch-and-swell structures. The presence of slump folds coeval with the extensional deformation, the variable extension directions obtained from the kinematic analysis and a weak cleavage recording layer-perpendicular shortening support the interpretation that gravitational collapse related to submarine sliding was the cause for extensional deformation. Well-consolidated rocks, located at the lower part of the stratigraphic sequence, also display scarce extensional faults. These extensional faults predate folding because they were breached by flexural-slip faults and, as a result of their passive rotation in fold limbs, these initial normal faults may now appear as reverse faults, particularly in steep and overturned limbs. The truncation of extensional faults by flexural-slip faults produces typical bed thickness changes across the extensional faults, giving rise to apparent synsedimentary faults. These normal faults can be attributed to the crustal extension that generated the passive continental margin or may represent deep parts of faults related to gravitational collapse. © 2007 International Association for Gondwana Research. Fil:Alonso, J.L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Ramos, V.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1342937X_v13_n2_p204_Alonso http://hdl.handle.net/20.500.12110/paper_1342937X_v13_n2_p204_Alonso
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Argentine Precordillera Extensional tectonics Gondwana Ordovician Submarine sliding
spellingShingle	Argentine Precordillera Extensional tectonics Gondwana Ordovician Submarine sliding Alonso, Jorge Luis Ramos, Victor Alberto Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera
topic_facet	Argentine Precordillera Extensional tectonics Gondwana Ordovician Submarine sliding
description	The paper describes ubiquitous extensional structures developed in a passive margin of Ordovician age in the Argentine Precordillera. These extensional structures include normal faults and boudinaged sequences. In some places the boudinage reaches very high extension values, giving rise to block-in-matrix formations. Most of these extensional structures developed when sediments were not well lithified, as recorded by hydroplastic fractures, slump folds and pinch-and-swell structures. The presence of slump folds coeval with the extensional deformation, the variable extension directions obtained from the kinematic analysis and a weak cleavage recording layer-perpendicular shortening support the interpretation that gravitational collapse related to submarine sliding was the cause for extensional deformation. Well-consolidated rocks, located at the lower part of the stratigraphic sequence, also display scarce extensional faults. These extensional faults predate folding because they were breached by flexural-slip faults and, as a result of their passive rotation in fold limbs, these initial normal faults may now appear as reverse faults, particularly in steep and overturned limbs. The truncation of extensional faults by flexural-slip faults produces typical bed thickness changes across the extensional faults, giving rise to apparent synsedimentary faults. These normal faults can be attributed to the crustal extension that generated the passive continental margin or may represent deep parts of faults related to gravitational collapse. © 2007 International Association for Gondwana Research.
author	Alonso, Jorge Luis Ramos, Victor Alberto
author_facet	Alonso, Jorge Luis Ramos, Victor Alberto
author_sort	Alonso, Jorge Luis
title	Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera
title_short	Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera
title_full	Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera
title_fullStr	Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera
title_full_unstemmed	Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera
title_sort	extensional tectonics and gravitational collapse in an ordovician passive margin: the western argentine precordillera
publishDate	2008
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1342937X_v13_n2_p204_Alonso http://hdl.handle.net/20.500.12110/paper_1342937X_v13_n2_p204_Alonso
work_keys_str_mv	AT alonsojorgeluis extensionaltectonicsandgravitationalcollapseinanordovicianpassivemarginthewesternargentineprecordillera AT ramosvictoralberto extensionaltectonicsandgravitationalcollapseinanordovicianpassivemarginthewesternargentineprecordillera
_version_	1768545989507940352

Extensional tectonics and gravitational collapse in an Ordovician passive margin: The Western Argentine Precordillera

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