Authors: Charley Beck, Justin Hawkins
Mentors: Alex Tye
Insitution: Utah Tech University
Thermochronometry dating of apatite (U-Th/He) of Andes Plate Tectonics from the Sierra de Altohuasi
Charley Beck, Justin Hawkins, Alex Tye
During the Cenozoic time period plate tectonics caused uplift in the Eastern Cordillera. We constrain the geologic evolution of the southernmost Eastern Cordillera through (U-Th/He) dating. Our results advance our understanding of the convergent plate boundary of the South American Plate and the Nazca Plate. The exhumation event caused the formation of the mountain range found in the Sierra de Altohuasi.
Four samples were collected in the Sierra de Altohuasi near the town of Corral Quemado, Catamarca Province, Argentina. The samples were then analyzed using an apatite (U-Th)/He) system. The results indicated exhumation of the Sierra de Altohuasi from 28.6-13.3 Ma. This suggests an episode of exhumation during the Miocene and Oligocene, due to subduction of the Nazca Plate under the South American Plate. These apatite (U-Th/He) ages better constrain the exhumation history of the Eastern Cordillera. Further studies will show correlation of uplift events of the surrounding areas of Corral Quemado. Due to the compressed South American Plate, our data suggests the large mountain range formed under movement of the Nazca Plate.