Temporal evolution of magma sources in Miocene magmatism southern Mendoza, Argentina.

OSTERA, H., HALLER, M., MACAMBIRA, M., RAMOS,A., CAGNONI, M. LÓPEZ DE LUCHI, M. AND LINARES,E.

Punta del Este

Simposio; V South American Symposium on Isotope Geology; 2006

Fac. de Ciencias y Fac. de Agronomía. Universidad de la República

New results on geochemical and isotope data, modeling and evolution of magmatic units with different ages from Lower to Upper Miocene in Southern Mendoza are presented. They suggest an increasing of Upper Crustal components in the Tertiary Magmatism of Southern Mendoza from Lower to Upper Miocene times. The isotope modeling indicates that the Lower Crustal component varies from Lower to Middle Miocene, due the continuous influx from the mantle. The explanation for the major Upper Crust involvement towards the Upper Miocene could be the slab flattening, which provokes a compressional regime and evolution of magmas in depth. The role of crustal erosion is still not well defined in the area, although some geochemical evidences are compatible with it.