Structural control on arc volcanism: The Caviahue-Copahue complex, Central to Patagonian Andes transition (38°S)

This paper describes the volcanostratigraphy, structure, and tectonic implications of an arc volcanic complex in an oblique subduction setting: the Caviahue caldera Copahue volcano (CAC) of the Andean margin. The CAC is located in a first-order morphotectonic transitional zone, between the low and n...

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Detalles Bibliográficos
Autores principales: Melnick, D., Folguera, A., Ramos, V.A.
Formato: JOUR
Materias:
Andes
Arc-parallel faults
Oblique subduction
Transfer zone
Volcanotectonic complex
caldera
island arc
oblique fault
pillow lava
pyroclastic flow
structural control
subduction zone
tectonic setting
transfer zone
volcanism
volcano
Argentina
Caviahue
Copahue
Neuquen
Patagonia
South America
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_08959811_v22_n1-2_p66_Melnick
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_08959811_v22_n1-2_p66_Melnick2023-10-03T15:42:41Z Structural control on arc volcanism: The Caviahue-Copahue complex, Central to Patagonian Andes transition (38°S) Melnick, D. Folguera, A. Ramos, V.A. Andes Arc-parallel faults Oblique subduction Transfer zone Volcanotectonic complex caldera island arc oblique fault pillow lava pyroclastic flow structural control subduction zone tectonic setting transfer zone volcanism volcano Andes Argentina Caviahue Copahue Neuquen Patagonia South America This paper describes the volcanostratigraphy, structure, and tectonic implications of an arc volcanic complex in an oblique subduction setting: the Caviahue caldera Copahue volcano (CAC) of the Andean margin. The CAC is located in a first-order morphotectonic transitional zone, between the low and narrow Patagonian and the high and broad Central Andes. The evolution of the CAC started at approximately 4-3 Ma with the opening of the 20 × 15 km Caviahue pull-apart caldera; Las Mellizas volcano formed inside the caldera and collapsed at approximately 2.6 Ma; and the Copahue volcano evolved in three stages: (1) 1.2-0.7 Ma formed the approximately 1 km thick andesitic edifice, (2) 0.7-0.01 Ma erupted andesitic-dacitic subglacial pillow lavas, and (3) 0.01-0 Ma erupted basaltic-andesites and pyroclastic flows from fissures, aligned cones, and summit craters. Magma ascent has occurred along planes perpendicular to the least principal horizontal stress, whereas hydrothermal activity and hot springs also occur along parallel planes. At a regional scale, Quaternary volcanism concentrates along the NE-trending, 90 km long Callaqui-Copahue-Mandolegüe lineament, the longest of the southern volcanic zone, which is here interpreted as an inherited crustal-scale transfer zone from a Miocene rift basin. At a local scale within the CAC, effusions are controlled by local structures that formed at the intersection of regional fault systems. The Central to Patagonian Andes transition occurs at the Callaqui-Copahue-Mandolegüe lineament, which decouples active deformation from the intra-arc strike-slip Liquiñe-Ofqui fault zone to the south and the backarc Copahue-Antiñir thrust system. © 2006 Elsevier Ltd. All rights reserved. Fil:Folguera, A. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_08959811_v22_n1-2_p66_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 Andes
Arc-parallel faults
Oblique subduction
Transfer zone
Volcanotectonic complex
caldera
island arc
oblique fault
pillow lava
pyroclastic flow
structural control
subduction zone
tectonic setting
transfer zone
volcanism
volcano
Andes
Argentina
Caviahue
Copahue
Neuquen
Patagonia
South America
spellingShingle Andes
Arc-parallel faults
Oblique subduction
Transfer zone
Volcanotectonic complex
caldera
island arc
oblique fault
pillow lava
pyroclastic flow
structural control
subduction zone
tectonic setting
transfer zone
volcanism
volcano
Andes
Argentina
Caviahue
Copahue
Neuquen
Patagonia
South America
Melnick, D.
Folguera, A.
Ramos, V.A.
Structural control on arc volcanism: The Caviahue-Copahue complex, Central to Patagonian Andes transition (38°S)
topic_facet Andes
Arc-parallel faults
Oblique subduction
Transfer zone
Volcanotectonic complex
caldera
island arc
oblique fault
pillow lava
pyroclastic flow
structural control
subduction zone
tectonic setting
transfer zone
volcanism
volcano
Andes
Argentina
Caviahue
Copahue
Neuquen
Patagonia
South America
description This paper describes the volcanostratigraphy, structure, and tectonic implications of an arc volcanic complex in an oblique subduction setting: the Caviahue caldera Copahue volcano (CAC) of the Andean margin. The CAC is located in a first-order morphotectonic transitional zone, between the low and narrow Patagonian and the high and broad Central Andes. The evolution of the CAC started at approximately 4-3 Ma with the opening of the 20 × 15 km Caviahue pull-apart caldera; Las Mellizas volcano formed inside the caldera and collapsed at approximately 2.6 Ma; and the Copahue volcano evolved in three stages: (1) 1.2-0.7 Ma formed the approximately 1 km thick andesitic edifice, (2) 0.7-0.01 Ma erupted andesitic-dacitic subglacial pillow lavas, and (3) 0.01-0 Ma erupted basaltic-andesites and pyroclastic flows from fissures, aligned cones, and summit craters. Magma ascent has occurred along planes perpendicular to the least principal horizontal stress, whereas hydrothermal activity and hot springs also occur along parallel planes. At a regional scale, Quaternary volcanism concentrates along the NE-trending, 90 km long Callaqui-Copahue-Mandolegüe lineament, the longest of the southern volcanic zone, which is here interpreted as an inherited crustal-scale transfer zone from a Miocene rift basin. At a local scale within the CAC, effusions are controlled by local structures that formed at the intersection of regional fault systems. The Central to Patagonian Andes transition occurs at the Callaqui-Copahue-Mandolegüe lineament, which decouples active deformation from the intra-arc strike-slip Liquiñe-Ofqui fault zone to the south and the backarc Copahue-Antiñir thrust system. © 2006 Elsevier Ltd. All rights reserved.
format JOUR
author Melnick, D.
Folguera, A.
Ramos, V.A.
author_facet Melnick, D.
Folguera, A.
Ramos, V.A.
author_sort Melnick, D.
title Structural control on arc volcanism: The Caviahue-Copahue complex, Central to Patagonian Andes transition (38°S)
title_short Structural control on arc volcanism: The Caviahue-Copahue complex, Central to Patagonian Andes transition (38°S)
title_full Structural control on arc volcanism: The Caviahue-Copahue complex, Central to Patagonian Andes transition (38°S)
title_fullStr Structural control on arc volcanism: The Caviahue-Copahue complex, Central to Patagonian Andes transition (38°S)
title_full_unstemmed Structural control on arc volcanism: The Caviahue-Copahue complex, Central to Patagonian Andes transition (38°S)
title_sort structural control on arc volcanism: the caviahue-copahue complex, central to patagonian andes transition (38°s)
url http://hdl.handle.net/20.500.12110/paper_08959811_v22_n1-2_p66_Melnick
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AT ramosva structuralcontrolonarcvolcanismthecaviahuecopahuecomplexcentraltopatagonianandestransition38s
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