EVIDENCIAS DE ACTIVIDAD EOLICA EN LA FORMACION QUEBRADA MONARDES OURASICO-CRETACICO INFERIOR) EN LA PRECORDILLERA DE COPIAPO, CHILE

Abstract

RESUMEN:The Quebrada Monardes Formation (Upper Jurassic?-Lower Cretaceous) exposed in the Precordillera of Copiapo, presents sedimentary structures which could be interpreted as formed by eolian processes. Ventifacts included in conglomerates of this formation exposed in Quebrada Codocedo, are the best proof of this. Slumped foresets are structures best explained as formed under subaerial conditions. Structures resembling "runzelmarken" (?) may also be indicative of wind activity. These data are consistent with the sabkha environmental conditions inferred for the deposition of part of the Quebrada Monardes Formation. Keywords: Eolian activity, Ventifacts, Upper Jurassic-Lower Cretaceous, Atacama desert, Chile. Palabras claves: Actividad eolica, Ventifactos, Jurasico Superior-Cretacico Inferior, Desierto de Atacama, Chile.