GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA

A comprehensive compilation of 651 (since 1968) radiometric ages determinations (415 40Ar/39Ar, 211 K/Ar, 5 U/Th, 4 Rb/Sr, 2 U/Pb, and 13 fission track thermochronology ages using zircon) provides a complete picture of the igneous stratigraphy of Costa Rica, and information about the age of the m...

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Autores Principales: Alvarado Induni, Guillermo E., Gans, Phillipe B.
Formato: Artículo
Idioma: Español
Publicado: Universidad de Costa Rica 2011
Materias:
Acceso en línea: http://revistas.ucr.ac.cr/index.php/geologica/article/view/1836
http://hdl.handle.net/10669/22411
id RepoKERWA22411
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spelling RepoKERWA224112017-08-08T18:49:54Z GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA Síntesis geocronológica del magmatismo, metamorfismo y metalogenia de Costa Rica, América Central Alvarado Induni, Guillermo E. Gans, Phillipe B. central america costa rica geochronology magmatism metamorphism metallogeny américa central costa rica geocronología magmatismo metamorfismo metalogenia A comprehensive compilation of 651 (since 1968) radiometric ages determinations (415 40Ar/39Ar, 211 K/Ar, 5 U/Th, 4 Rb/Sr, 2 U/Pb, and 13 fission track thermochronology ages using zircon) provides a complete picture of the igneous stratigraphy of Costa Rica, and information about the age of the major metamorphic and metalogenic events in the region. Igneous rocks of Late Jurassic to Middle Eocene age (~ 160 to ~ 41 Ma), mainly accreted ophiolites. At the beginning of Campanian time (~ 71 Ma), the actual subduction zone was established, represented by volcano-sedimentary rocks of basic to felsic composition. However, voluminous subalkaline, primary volcanic rocks appeared only after ~ 29 Ma. Intrusive to hypabyssal granitic to gabboic plutons, stocks, equivalent dykes and sills, are widely exposed in the Talamanca range (~ 12.4 - 7.8 Ma), Cerros de Escazú (~ 6.0 - 5.9 Ma), and Fila Costeña (~ 18.3 - 16.8 and ~ 14.8 - 11.1 Ma), Tapantí-Montes del Aguacate-Carpintera (~ 4.2 - 2.2 Ma) and Guacimal (~ 6.4 - 5.2 Ma). Arc rocks between 29 and 11 Ma are known in the San Carlos plains and in southern Costa Rica. The location and age of the igneous rocks indicated that there was a 20°counterclockwise rotation of the arc (termed as Proto-Volcanic Front) between 15 and 8 Ma, with a pole of rotation centered on southern Costa Rica. This rotation is attributed to deformation in the overriding plate (shortening in the south coeval with extension in the NW), accompanied by trench retreat in the south. At ~ 3.45 Ma arc-related volcanism shut off in southern part of the region, but local acid-adakite volcanism persisted in the Talamanca range (4.2 - 0.95 Ma) due to the subduction of the Cocos Ridge. The Paleo-Volcanic Front is represented by arc-related rocks (8 - 3.5 Ma) along the length of Costa Rica, parallel to but in front of the modern arc. This activity was followed by the Monteverde (2.1 - 1.1 Ma) andesitic/basaltic effusive event, which progressively volcanoes grew mainly during the last 0,6 Ma. In general, modern volcanoes represent three volcanic episodes: ancestral cone/shield building at ~ 1,61 - 0,85 Ma (Proto-Cordillera), overlapping in part with Monteverde volcanism; a major constructive event at ~ 0,74 - ~ 0,2 Ma (Paleo-Cordillera), and a relatively small but still active volcanism at 0,25 - 0 Ma (Neo-Cordillera). Submarine volcanism in the Pacific is represented by the Fisher Ridge (30.0 and 19.2 Ma), the Cocos Ridge (14,5 – 0,6 Ma), including the sub-aerial volcanism of Cocos Island (2,2 - 1,5 Ma). The major magmatic, metamorphic and metallogenic events are clearly related to major geotectonic events, including regional unconformities, at Upper Cretaceous (~ 82 Ma), Middle Eocene (~ 45 Ma) and Upper Miocene (~ 8 Ma). Una recopilación completa de 651 determinaciones de edades radiométricas desde 1968 (415 dataciones 40Ar/39Ar, 211 K/Ar, 5 U/Th, 4 Rb/Sr, 2 U/Pb y de fisión termocronología con zircón), tanto aquellas publicadas desde 1968 como muchas nuevas, proporcionan un marco completo de la estratigrafía ígnea de Costa Rica y las inferencias acerca de la edad del metamorfismo y los eventos metalogenéticos. Las rocas ígneas del Jurásico Superior temprano al Eoceno Medio (~ 160 a ~ 41 Ma), corresponden principalmente con acreciones ofiolíticas. Durante el Campaniano (~ 71 Ma) comienza a establecerse la actual zona de subducción, conformada por rocas volcano-sedimentarias, con una composición desde básica a félsica. Sin embargo, las rocas volcánicas primarias, subalcalinas, in situ y abundantes, aparecen hasta después de los ~ 29 Ma. Los intrusivos e hipoabisales de granitoides hasta gabroides (plutones, stocks, diques y sills), están presentes de SE a NW en: la cordillera de Talamanca (~ 12,4 a 7,8 Ma), cerros de Escazú (~ 6,0 a 5,9 Ma), fila Costeña (~ 18,3 a 16,8 y ~ 14,8 a 11,1 Ma), Tapantí-montes del Aguacate-Carpintera (~ 4,2 a 2,2 Ma) y Guacimal (~ 6,4 a 5,2 Ma). Las rocas asociadas al arco con edades entre los 29 y 11 Ma (denominado Frente Proto- Volcánico), están presentes en la llanura de San Carlos y en el sur de Costa Rica. La ubicación y la edad de las rocas ígneas indican que el arco dio un giro de 20° al NW entre 15 y 8 Ma, con un polo de rotación que se centró en el sur de Costa Rica. Esta rotación se atribuye a la deformación en la placa superior (acortamiento en el sur y extensión en el noroeste), acompañado por el retroceso de la trinchera hacia el sur. A los ~ 3,45 Ma, el arco volcánico en el sur cesó su actividad, mientras que el vulcanismo adakítico localizado persistió en la cordillera de Talamanca (4,2 - 0,95 Ma) debido a la subducción de las Placa Cocos. El Frente Paleo-Volcánico está representada por rocas del arco (8 - 3,5 Ma) que se extienden a lo largo de Costa Rica, de forma paralela al arco volcánico moderno y fue seguido por el evento efusivo Monteverde (2,1 - 1,1 Ma), que progresivamente se retrocedió hacia el NE. El Frente Neovolcánico se estableció entre el 2,1 y el presente, con el crecimiento de los actuales volcanes, mayoritariamente hace unos 0,6 Ma y, en general, están representados por tres episodios, no isocrónicos entre volcanes: volcanes ancestrales entre 1,61 y 0,85 Ma (Proto-Cordillera), en parte coetánea con Monteverde; un evento importante cerca de ~ 0,74 - ~ 0,2 Ma (Paleo-Cordillera), y una actividad volcánica relativamente pequeña, pero activa aún en 0,25 - 0 Ma (Neo-Cordillera). El vulcanismo submarino en aguas del Pacífico costarricense, está representado por la serranía Fisher (30,0 Ma y 19,2 Ma), la cordillera del Coco (14,5 - 0,6 Ma) y el vulcanismo subaéreo de la isla del Coco (2,2 - 1,5 Ma). Los principales eventos magmáticos, metamórficos y metalogéneticos están relacionados con los principales eventos geotectónicos, incluyendo discordancias regionales en Cretácico Superior (~ 82 Ma), Eoceno Medio (~ 45 Ma) y el Mioceno Superior (~ 8 Ma). 2011-04-02 2016-05-03T14:24:38Z 2016-05-03T14:24:38Z info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://revistas.ucr.ac.cr/index.php/geologica/article/view/1836 10.15517/rgac.v0i46.1836 http://hdl.handle.net/10669/22411 spa Revista Geológica de América Central; Copyright (c) 2014 Revista Geológica de América Central application/pdf Universidad de Costa Rica Revista Geológica de América Central; Revista Geológica de América Central: Número 46 Revista Geológica de América Central; Revista Geológica de América Central: Número 46 2215-261X 0256-7024
institution Universidad de Costa Rica
collection Repositorio KERWA
language Español
topic central america
costa rica
geochronology
magmatism
metamorphism
metallogeny
américa central
costa rica
geocronología
magmatismo
metamorfismo
metalogenia
spellingShingle central america
costa rica
geochronology
magmatism
metamorphism
metallogeny
américa central
costa rica
geocronología
magmatismo
metamorfismo
metalogenia
Alvarado Induni, Guillermo E.
Gans, Phillipe B.
GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA
description A comprehensive compilation of 651 (since 1968) radiometric ages determinations (415 40Ar/39Ar, 211 K/Ar, 5 U/Th, 4 Rb/Sr, 2 U/Pb, and 13 fission track thermochronology ages using zircon) provides a complete picture of the igneous stratigraphy of Costa Rica, and information about the age of the major metamorphic and metalogenic events in the region. Igneous rocks of Late Jurassic to Middle Eocene age (~ 160 to ~ 41 Ma), mainly accreted ophiolites. At the beginning of Campanian time (~ 71 Ma), the actual subduction zone was established, represented by volcano-sedimentary rocks of basic to felsic composition. However, voluminous subalkaline, primary volcanic rocks appeared only after ~ 29 Ma. Intrusive to hypabyssal granitic to gabboic plutons, stocks, equivalent dykes and sills, are widely exposed in the Talamanca range (~ 12.4 - 7.8 Ma), Cerros de Escazú (~ 6.0 - 5.9 Ma), and Fila Costeña (~ 18.3 - 16.8 and ~ 14.8 - 11.1 Ma), Tapantí-Montes del Aguacate-Carpintera (~ 4.2 - 2.2 Ma) and Guacimal (~ 6.4 - 5.2 Ma). Arc rocks between 29 and 11 Ma are known in the San Carlos plains and in southern Costa Rica. The location and age of the igneous rocks indicated that there was a 20°counterclockwise rotation of the arc (termed as Proto-Volcanic Front) between 15 and 8 Ma, with a pole of rotation centered on southern Costa Rica. This rotation is attributed to deformation in the overriding plate (shortening in the south coeval with extension in the NW), accompanied by trench retreat in the south. At ~ 3.45 Ma arc-related volcanism shut off in southern part of the region, but local acid-adakite volcanism persisted in the Talamanca range (4.2 - 0.95 Ma) due to the subduction of the Cocos Ridge. The Paleo-Volcanic Front is represented by arc-related rocks (8 - 3.5 Ma) along the length of Costa Rica, parallel to but in front of the modern arc. This activity was followed by the Monteverde (2.1 - 1.1 Ma) andesitic/basaltic effusive event, which progressively volcanoes grew mainly during the last 0,6 Ma. In general, modern volcanoes represent three volcanic episodes: ancestral cone/shield building at ~ 1,61 - 0,85 Ma (Proto-Cordillera), overlapping in part with Monteverde volcanism; a major constructive event at ~ 0,74 - ~ 0,2 Ma (Paleo-Cordillera), and a relatively small but still active volcanism at 0,25 - 0 Ma (Neo-Cordillera). Submarine volcanism in the Pacific is represented by the Fisher Ridge (30.0 and 19.2 Ma), the Cocos Ridge (14,5 – 0,6 Ma), including the sub-aerial volcanism of Cocos Island (2,2 - 1,5 Ma). The major magmatic, metamorphic and metallogenic events are clearly related to major geotectonic events, including regional unconformities, at Upper Cretaceous (~ 82 Ma), Middle Eocene (~ 45 Ma) and Upper Miocene (~ 8 Ma).
format Artículo
author Alvarado Induni, Guillermo E.
Gans, Phillipe B.
author_sort Alvarado Induni, Guillermo E.
title GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA
title_short GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA
title_full GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA
title_fullStr GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA
title_full_unstemmed GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA
title_sort geochronological synthesis of magmatism, metamorphism and metallogeny of costa rica, central america
publisher Universidad de Costa Rica
publishDate 2011
url http://revistas.ucr.ac.cr/index.php/geologica/article/view/1836
http://hdl.handle.net/10669/22411
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score 11.69571