Contribution to the age of the Somún Curá Post-Plateau Events. Extra Andean Argentinean Patagonia

SALANI, F. M., M. B. REMESAL, M. E CERREDO, M. FRANCHI, A. A. ARDOLINO

Punta del Este. Uruguay

Simposio; V Simposio Sudamericano de Geología Isotópica (SSAGI); 2006

SSAGI

During Late Oligocene-Miocene in the north of Extra Andean Argentinean Patagonia (Somún Curá basaltic plateau) a post plateau stage is represented by several eruptive centers of different complexities. According to the wide compositional and eruptive diversity can be distinguished two major types: a) large bimodal complexes and b) monogenetic eruptive centers.  New WR K/Ar ages are presented here for two of the monogenetic post-plateau centers, the Trayén Niyeu Volcano and Dos Hermanos Hills and compared with others coeval centres. Petrography, geochemistry and geochronology point out the monogenetic eruptive centers of subalkaline affinities as Trayén Niyeu result contemporaneous with other monogenetic and bimodal centers of the post-plateau alkaline sequence.