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Geochronological synthesis of magmatism, metamorphism and metallogeny of Costa Rica, Central America; Sintesis geocronologica del magmatismo, metamorfismo y metalogenia de Costa Rica, America Central

Journal Article:

Abstract

A comprehensive compilation of 651 (since 1968) radiometric ages determinations (415 {sup 40}Ar/{sup 39}Ar, 211 K/Ar, 5 U/Th, 4 Rb/Sr, 2 U/Pb, and 13 fission track thermochronology ages using zircon) have provided a complete picture of the igneous stratigraphy of Costa Rica, and information about the age of the major metamorphic and metallogenic events in the region. Igneous rocks of Late Jurassic to Middle Eocene age ({approx} 160 to {approx} 41 Ma), mainly accreted ophiolites. The actual subduction zone was established, represented by volcano-sedimentary rocks of basic to felsic composition, at the beginning of Campanian time ({approx} 71 Ma). However, voluminous subalkaline, primary volcanic rocks have appeared only after {approx} 29 Ma. Intrusive to hypabyssal granitic to gabboic plutons, stocks, equivalent dykes and sills, are widely exposed in the Talamanca range ({approx} 12,4 - 7,8 Ma), hills of Escazu ({approx} 6,0 - 5,9 Ma), and Fila Costena ({approx} 18,3 - 16,8 and {approx} 14,8 - 11,1 Ma), Tapanti-Montes del Aguacate-Carpintera ({approx} 4,2 - 2,2 Ma) and Guacimal ({approx} 6,4 - 5,2 Ma). Arc rocks between 29 and 11 Ma (called Photo-Volcanic Front) are known in the San Carlos plains and in southern Costa Rica. The location and age of the  More>>
Publication Date:
Jun 15, 2012
Product Type:
Journal Article
Resource Relation:
Journal Name: Revista Geologica de America Central; Journal Issue: 46; Other Information: Figs., refs.
Subject:
58 GEOSCIENCES; 54 ENVIRONMENTAL SCIENCES; CALCITE; FORAMINIFERA; GEOLOGIC STRUCTURES; GRENADA; ISOTOPE RATIO; NUMERICAL DATA; PLANKTON; SEAS; SEDIMENTARY ROCKS; SEDIMENTATION; STRONTIUM 86; STRONTIUM 87
OSTI ID:
22060701
Country of Origin:
Costa Rica
Language:
Spanish
Other Identifying Numbers:
Journal ID: ISSN 0256-7024; TRN: CR1300001019683
Availability:
Also available from Biblioteca Luis Demetrio Tinoco, Universidad de Costa Rica
Submitting Site:
INIS
Size:
page(s) 7-122
Announcement Date:
Mar 07, 2013

Journal Article:

Citation Formats

Alvarado, Guillermo E., E-mail: galvarado@ice.go.cr [Inst. Costarricense de Electricidad, Apdo. 10032, 1000 San Jose (Costa Rica), Univ. de Costa Rica, Centro de Investigaciones Geologicas, Apdo. 35-2060 (Costa Rica)], and Gans, Phillipe B. Geochronological synthesis of magmatism, metamorphism and metallogeny of Costa Rica, Central America; Sintesis geocronologica del magmatismo, metamorfismo y metalogenia de Costa Rica, America Central. Costa Rica: N. p., 2012. Web.
Alvarado, Guillermo E., E-mail: galvarado@ice.go.cr [Inst. Costarricense de Electricidad, Apdo. 10032, 1000 San Jose (Costa Rica), Univ. de Costa Rica, Centro de Investigaciones Geologicas, Apdo. 35-2060 (Costa Rica)], & Gans, Phillipe B. Geochronological synthesis of magmatism, metamorphism and metallogeny of Costa Rica, Central America; Sintesis geocronologica del magmatismo, metamorfismo y metalogenia de Costa Rica, America Central. Costa Rica.
Alvarado, Guillermo E., E-mail: galvarado@ice.go.cr [Inst. Costarricense de Electricidad, Apdo. 10032, 1000 San Jose (Costa Rica), Univ. de Costa Rica, Centro de Investigaciones Geologicas, Apdo. 35-2060 (Costa Rica)], and Gans, Phillipe B. 2012. "Geochronological synthesis of magmatism, metamorphism and metallogeny of Costa Rica, Central America; Sintesis geocronologica del magmatismo, metamorfismo y metalogenia de Costa Rica, America Central." Costa Rica.
@misc{etde_22060701,
title = {Geochronological synthesis of magmatism, metamorphism and metallogeny of Costa Rica, Central America; Sintesis geocronologica del magmatismo, metamorfismo y metalogenia de Costa Rica, America Central}
author = {Alvarado, Guillermo E., E-mail: galvarado@ice.go.cr [Inst. Costarricense de Electricidad, Apdo. 10032, 1000 San Jose (Costa Rica), Univ. de Costa Rica, Centro de Investigaciones Geologicas, Apdo. 35-2060 (Costa Rica)], and Gans, Phillipe B}
abstractNote = {A comprehensive compilation of 651 (since 1968) radiometric ages determinations (415 {sup 40}Ar/{sup 39}Ar, 211 K/Ar, 5 U/Th, 4 Rb/Sr, 2 U/Pb, and 13 fission track thermochronology ages using zircon) have provided a complete picture of the igneous stratigraphy of Costa Rica, and information about the age of the major metamorphic and metallogenic events in the region. Igneous rocks of Late Jurassic to Middle Eocene age ({approx} 160 to {approx} 41 Ma), mainly accreted ophiolites. The actual subduction zone was established, represented by volcano-sedimentary rocks of basic to felsic composition, at the beginning of Campanian time ({approx} 71 Ma). However, voluminous subalkaline, primary volcanic rocks have appeared only after {approx} 29 Ma. Intrusive to hypabyssal granitic to gabboic plutons, stocks, equivalent dykes and sills, are widely exposed in the Talamanca range ({approx} 12,4 - 7,8 Ma), hills of Escazu ({approx} 6,0 - 5,9 Ma), and Fila Costena ({approx} 18,3 - 16,8 and {approx} 14,8 - 11,1 Ma), Tapanti-Montes del Aguacate-Carpintera ({approx} 4,2 - 2,2 Ma) and Guacimal ({approx} 6,4 - 5,2 Ma). Arc rocks between 29 and 11 Ma (called Photo-Volcanic Front) are known in the San Carlos plains and in southern Costa Rica. The location and age of the igneous rocks have indicated that there was a 20 degrees counterclockwise rotation of the arc (termed as Proto-Volcanic Front) between 15 and 8 Ma, with a pole of rotation that has 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 {approx} 3,45 Ma, arc-related volcanism has shut off in southern part of the region, but local acid-adakite volcanism has 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 has retreated to the NE. Thus, the Neo-Volcanic Front was established between 2,1 and the present, in which the modern volcanoes grew mainly during the last 0,6 Ma. In general, modern volcanoes represent three volcanic episodes: ancestral cone/shield building at {approx} 1,61 - 0,85 Ma (Proto-Range), overlapping in part with Monteverde volcanism; a major constructive event at {approx} 0,74 - {approx} 0,2 Ma (Paleo-Range), and a relatively small but still active volcanism at 0,25 - 0 Ma (Neo-Range). Submarine volcanism in the Costa Rican 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, included regional unconformities, at Upper Cretaceous ({approx} 82 Ma), Middle Eocene ({approx} 45 Ma) and Upper Miocene ({approx} 8 Ma). (author) [Spanish] Una recopilacion completa de 651 determinaciones de edades radiometricas desde 1968 (415 dataciones {sup 40}Ar/{sup 39}Ar, 211 K/Ar, 5 U/Th, 4 Rb/Sr, 2 U/Pb y de 13 edades de termocronologia de fision en trazos con circon), tanto aquellas publicadas desde 1968 como muchas nuevas, han proporcionado un marco completo de la estratigrafia ignea de Costa Rica y las inferencias acerca de la edad del metamorfismo y los eventos metalogeneticos en la region. Las rocas igneas del Jurasico Superior temprano al Eoceno Medio ({approx} 160 a {approx} 41 Ma), han correspondido principalmente con acreciones ofioliticas. La actual zona de subduccion, conformada por rocas volcano-sedimentarias, ha comenzado a establecerse con una composicion desde basica a felsica, durante el Campaniano ({approx} 71 Ma). Sin embargo, las rocas volcanicas primarias, subalcalinas, in situ y abundantes, han aparecido hasta despues de los {approx} 29 Ma. Los intrusivos e hipoabisales de granitoides hasta gabroides (plutones, stocks, diques y sills), han estado presentes de SE a NW en: la cordillera de Talamanca ({approx} 12,4 a 7,8 Ma), cerros de Escazu ({approx} 6,0 a 5,9 Ma), Fila Costena ({approx} 18,3 a 16,8 y {approx} 14,8 a 11,1 Ma), Tapanti-Montes del Aguacate-Carpintera ({approx} 4,2 a 2,2 Ma) y Guacimal ({approx} 6,4 a 5,2 Ma). Las rocas asociadas al arco con edades entre los 29 y 11 Ma (denominado Frente Proto- Volcanico), han estado presentes en la llanura de San Carlos y en el sur de Costa Rica. La ubicacion y la edad de las rocas igneas han indicado que el arco dio un giro de 20 grados al NW (denominado Frente Proto-Volcanico) entre 15 y 8 Ma, con un polo de rotacion que se ha centrado en el sur de Costa Rica. Esta rotacion es atribuida a la deformacion en la placa superior (acortamiento en el sur y extension en el noroeste), acompanado por el retroceso de la trinchera hacia el sur. A los {approx} 3,45 Ma, el arco volcanico en el sur ha cesado su actividad, mientras que el vulcanismo adakitico localizado ha persistido en la cordillera de Talamanca (4,2 - 0,95 Ma) debido a la subduccion de la Placa Cocos. El Frente Paleo-Volcanico esta representado por rocas del arco (8 - 3,5 Ma) que se han extendido a lo largo de Costa Rica, de forma paralela al arco volcanico moderno y fue seguido por el evento efusivo Monteverde (2,1 - 1,1 Ma), que progresivamente se ha retrocedido hacia el NE. El Frente Neovolcanico se ha establecido entre el 2,1 y el presente, con el crecimiento de los actuales volcanes, mayoritariamente hace unos 0,6 Ma y, en general, estan representados por tres episodios, no isocronicos entre volcanes: volcanes ancestrales entre 1,61 y 0,85 Ma (Proto-Cordillera), en parte coetanea con Monteverde; un evento importante cerca de {approx} 0,74 - {approx} 0,2 Ma (Paleo-Cordillera), y una actividad volcanica relativamente pequena, pero activa aun en 0,25 - 0 Ma (Neo-Cordillera). El vulcanismo submarino en aguas del Pacifico costarricense, esta representado por la serrania Fisher (30,0 Ma y 19,2 Ma), la cordillera del Coco (14,5 - 0,6 Ma) y el vulcanismo subaereo de la Isla del Coco (2,2 - 1,5 Ma). Los principales eventos magmaticos, metamorficos y metalogeneticos estan relacionados con los principales eventos geotectonicos, incluidas discordancias regionales en Cretacico Superior ({approx} 82 Ma), Eoceno Medio ({approx} 45 Ma) y el Mioceno Superior ({approx} 8 Ma). (autor)}
journal = {Revista Geologica de America Central}
issue = {46}
journal type = {AC}
place = {Costa Rica}
year = {2012}
month = {Jun}
}