Revista Geológica de América Central, 46: 7-122, 2012 ISSN: 0256-7024 SÍNTESIS GEOCRONOLÓGICA DEL MAGMATISMO, METAMORFISMO Y METALOGENIA DE COSTA RICA, AMÉRICA CENTRAL GEOCHRONOLOGICAL SYNTHESIS OF MAGMATISM, METAMORPHISM AND METALLOGENY OF COSTA RICA, CENTRAL AMERICA Guillermo E. Alvarado1,2* & Phillipe B. Gans3 1Instituto Costarricense de Electricidad, Apdo. 10032, 1000 San José, Costa Rica 2Centro de Investigaciones Geológicas, Apdo. 35-2060 Universidad de Costa Rica, San José, Costa Rica 3Department of Geological Sciences, University of California, Santa Barbara, CA 93106, USA *Autor para contacto:
[email protected] (Recibido: 15/10/2011; aceptado: 11/06/2012) ABSTRACT: 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).