Geological characteristics of the "?Loma Colorada"?, Choya Department, Province of Santiago del Estero, Argentina

Abstract

?Geological characteristics of the ?Loma Colorada?, Choya Department, Province of Santiago del Estero, Argentina?. The ?Loma Colorada?, which presents a group of elevations at the lenght of 3,5 km, is located a few kilometers from the southern end of the Sierra de Guasayan and from the western one of the Cerro Ichagon. It consists almost exclusively of a set of piroclastic rocks which belong to the Fm Sol de Mayo. Two types of tufas ?the welded and the cystalline ones? have been differentiated in the piroclastic sequence. The Cerrillos Cerro Ichagon is considered to be the emitting center due to the recurrent vulcanism. The pulses of activity of it belong to the Late Carboniferous ?Early Permian, Upper Triassic? Early Jurassic and Upper Miocene. The referred rocks are located in the first pulse. The hydrotermal alteration has manifested itself as silification and argillic alteration.