Edades U-Pb en circones detríticos de las metasedimentitas del cordón del Peñasco, Precordillera de Mendoza

PEREZ LUJAN, S; VUJOVICH, G; PEREZ LUJAN, S; VUJOVICH, G; NAIPAUER, M.; PIMENTEL, M.; NAIPAUER, M.; BOEDO, F; PIMENTEL, M.; ARIZA, J P; BOEDO, F; ARIZA, J P

San Miguel de Tucumán

Congreso; XX Congreso Geológico Argentino; 2017

Universidad Nacional de Tucumán

In central-western Argentina, a belt of slope and deep marine metasedimentary rocks is associated with mafic and ultramafic bodies throught the western margin of the Precordillera. The belt is assigned to the late Neoproterozoic-Early Devonian based on U-Pb data and fossil fauna. It is considered to represent the suture zone between the Cuyania (to the east) and the Chilenia (to the west) terranes. We present here the first U-Pb data on detrital zorcons of metasedimentary rocks from the Cordón del Peñasco area, northern Precordillera of Mendoza. Two metasandstones from the same unit (Peñasco Formation) were collected at the eastern and westernmost sectors of the study area. They yielded different zircon morphologies, population dsitributios and maximun depositional ages (534 Ma for the westermost sample and 485 Ma for the easternost one). The obteined results confirm that local stratigraphical scheme needs revision. They also confirm the existence of a basin wich separated the Cuyania and the Chilenia terranes at early Cambrian times. Besides, the different zircon populations registered reveal a change in provenance areas, wich could be possibly related to the Ocloyic orogeny during middle-late Ordovician.