Neogene tectonic evolution of the Neuquén Andes western flank (37-39°S)

This paper integrates new field observations to summarize the evolution of the 37-39°S segment of the Andean margin during the Neogene period. The western Neuquén Andes represent a transitional segment between the high, broad Central Andes and the low, narrow Patagonian Andes. The Main Cordillera at...

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Detalles Bibliográficos
Publicado: 2006
Materias:
Arc-parallel fault zones
Main cordillera
Tectonic evolution
Western neuquén andes
cordillera
deformation
exhumation
fault zone
faulting
island arc
migration
Miocene
Neogene
subduction
tectonic evolution
transtension
uplift
Andes
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00721077_v407_n_p73_Melnick
http://hdl.handle.net/20.500.12110/paper_00721077_v407_n_p73_Melnick
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00721077_v407_n_p73_Melnick
record_format dspace
spelling paper:paper_00721077_v407_n_p73_Melnick2023-06-08T15:06:35Z Neogene tectonic evolution of the Neuquén Andes western flank (37-39°S) Arc-parallel fault zones Main cordillera Tectonic evolution Western neuquén andes cordillera deformation exhumation fault zone faulting island arc migration Miocene Neogene subduction tectonic evolution transtension uplift Andes This paper integrates new field observations to summarize the evolution of the 37-39°S segment of the Andean margin during the Neogene period. The western Neuquén Andes represent a transitional segment between the high, broad Central Andes and the low, narrow Patagonian Andes. The Main Cordillera at this latitude was uplifted between 11 and 6 Ma. Since then, extension and transtension has dominated the area. South of 38°S, deformation concentrates along the Liquiñe-Ofqui fault zone, a crustal-scale dextral strike-slip system that accommodates part of the marginparallel component of oblique subduction. The architecture of the volcanic arc is strongly controlled by this fault zone. We differentiate four main tectonic phases: (1) late Oligocene-middle Miocene extension and development of a segmented intra-arc continental rift basin and broad volcanic zone; (2) late Miocene shortening, resulting in uplift, exhumation, and inversion of the former basins and a volcanic gap in the Main Cordillera; (3) Pliocene-early Pleistocene extension of the orogenic structure, reestablishment of the volcanic arc, and transtension along the intra-arc zone; and (4) late Pleistocene-Holocene narrowing of the arc and localized extension-transtension along the axial intra-arc zone. In the Central Andes, shortening has been more or less continuous since the Miocene, whereas in the Neuquén Andes, shortening stopped at ca. 6 Ma, probably related to the increase of the slab angle triggering the extension of the former orogenic structure and the onset of arc-parallel strike-slip faulting. The episodic evolution and migration of volcanism are related to changes in dip of the subducting plate. © 2006 Geological Society of America. 2006 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00721077_v407_n_p73_Melnick http://hdl.handle.net/20.500.12110/paper_00721077_v407_n_p73_Melnick
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Arc-parallel fault zones
Main cordillera
Tectonic evolution
Western neuquén andes
cordillera
deformation
exhumation
fault zone
faulting
island arc
migration
Miocene
Neogene
subduction
tectonic evolution
transtension
uplift
Andes
spellingShingle Arc-parallel fault zones
Main cordillera
Tectonic evolution
Western neuquén andes
cordillera
deformation
exhumation
fault zone
faulting
island arc
migration
Miocene
Neogene
subduction
tectonic evolution
transtension
uplift
Andes
Neogene tectonic evolution of the Neuquén Andes western flank (37-39°S)
topic_facet Arc-parallel fault zones
Main cordillera
Tectonic evolution
Western neuquén andes
cordillera
deformation
exhumation
fault zone
faulting
island arc
migration
Miocene
Neogene
subduction
tectonic evolution
transtension
uplift
Andes
description This paper integrates new field observations to summarize the evolution of the 37-39°S segment of the Andean margin during the Neogene period. The western Neuquén Andes represent a transitional segment between the high, broad Central Andes and the low, narrow Patagonian Andes. The Main Cordillera at this latitude was uplifted between 11 and 6 Ma. Since then, extension and transtension has dominated the area. South of 38°S, deformation concentrates along the Liquiñe-Ofqui fault zone, a crustal-scale dextral strike-slip system that accommodates part of the marginparallel component of oblique subduction. The architecture of the volcanic arc is strongly controlled by this fault zone. We differentiate four main tectonic phases: (1) late Oligocene-middle Miocene extension and development of a segmented intra-arc continental rift basin and broad volcanic zone; (2) late Miocene shortening, resulting in uplift, exhumation, and inversion of the former basins and a volcanic gap in the Main Cordillera; (3) Pliocene-early Pleistocene extension of the orogenic structure, reestablishment of the volcanic arc, and transtension along the intra-arc zone; and (4) late Pleistocene-Holocene narrowing of the arc and localized extension-transtension along the axial intra-arc zone. In the Central Andes, shortening has been more or less continuous since the Miocene, whereas in the Neuquén Andes, shortening stopped at ca. 6 Ma, probably related to the increase of the slab angle triggering the extension of the former orogenic structure and the onset of arc-parallel strike-slip faulting. The episodic evolution and migration of volcanism are related to changes in dip of the subducting plate. © 2006 Geological Society of America.
title Neogene tectonic evolution of the Neuquén Andes western flank (37-39°S)
title_short Neogene tectonic evolution of the Neuquén Andes western flank (37-39°S)
title_full Neogene tectonic evolution of the Neuquén Andes western flank (37-39°S)
title_fullStr Neogene tectonic evolution of the Neuquén Andes western flank (37-39°S)
title_full_unstemmed Neogene tectonic evolution of the Neuquén Andes western flank (37-39°S)
title_sort neogene tectonic evolution of the neuquén andes western flank (37-39°s)
publishDate 2006
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00721077_v407_n_p73_Melnick
http://hdl.handle.net/20.500.12110/paper_00721077_v407_n_p73_Melnick
_version_ 1768541743648604160

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