Authors: Justin Hawkins, Charley Beck
Mentors: Alex Tye
Insitution: Utah Tech University
This study aims to address a critical gap in our understanding of the geological history and tectonic evolution of the Andes mountain range in Argentina. The Andes were formed due to a convergent boundary between the Nazca and South American plates. We are interested in the history of this boundary and how these mountains were formed. To better constrain the history of crustal deformation in NW Argentina, we collected samples from the Sierra de Chango Real, located south and along-strike of the Eastern Cordillera, and conducted new apatite (U-Th)/He dating on these samples. We combined new apatite (U-Th)/He data with the existing apatite fission-track data to gain a more comprehensive perspective on the geological evolution of the region.
Apatite (U-Th)/He ages for new samples from the Sierra de Chango Real are between 6.3 and 17.6 Ma. These ages indicate Miocene exhumation of the Sierra de Chango Real due to tectonic deformation. Also, the distribution of these ages within the samples offers valuable information regarding variations in uplift rates and thermal events, which contribute to a better understanding of the geological processes that have shaped the Andes mountains. Published apatite fission track ages from the same locations have ages of 38 Ma to 30 Ma. Together, the thermochronometric ages suggest a history of tectonic exhumation from 38 Ma until ca. 6 Ma. In conclusion, our current study and analysis of samples taken from Sierra de Chango Real, Argentina, in conjunction with published apatite fission-track data, contributes to a more comprehensive understanding of the region's geological history.