Edades radiométricas de algunas rocas de Antioquia-Colombia
1980; National University of Colombia; Issue: 5 Linguagem: Espanhol
ISSN
2357-3740
AutoresJorge Julián Restrepo, Jean François Toussaint,
Tópico(s)Geological and Tectonic Studies in Latin America
ResumoespanolLa datacion por el metodo K/Ar de cinco muestras de rocas metamorficas e igneas basicas permite detallar algunos eventos que tuvieron lugar durante el Cretaceo en el Occidente Colombiano: Las edades radiometricas indican que: 1) La corteza oceanica del Occidente Colombiano se formo durante el Cretaceo temprano. 2) Durante el Albiano, parte de esta corteza se obdujo sobre el basamento cristalino de la Cordillera Central. Esta obduccion produjo un intenso metamorfismo dinamico-termico, el cual presenta algunas caracteristicas de metamorfismos de media presion. 3) Durante el Cretaceo tardio hubo magmatismo basico en el flanco oriental de la Cordillera Occidental. Este magmatismo, que es contemporaneo del Batolito antioqueno de la Cordillera Central, parece corresponder a un arco insular incipiente. EnglishThe dating by the K/Ar method of five samples of metamorphic and basic igneous rocks from the Department of Antioquia give a better understanding of the geological history of Western Colombia during the Cretaceous.The radiometric ages indicate that: 1) The oceanic crust present in Western Colombia was formed during the Early Cretaceous. 2) During the Albian, this oceanic crust was obducted over the continental crust of the Central Cordillera. The obduction produced an intense dinamo-thermal metamorphism of medium-pressure type (Barrovian). 3) During the Late Cretaceous there was basic magmatism in the eastern flank of the Western Cordillera. This magmatism contemporaneous with the Antioquian Batholith of the Central Cordillera, seems to have been generated in an incipient island-arc environment.
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