THE NORTH PATAGONIAN ALTIPLANO AND THE SOMÓN CURÁ BASALTIC PLATEAU

Resumo

For some time it has been considered that the Somón Curá basaltic plateau, at the edge of the North Patagonian Massif, was originated by inversion of relief. Recent observations allowed the hypothesis that the generation of the North Patagonian altiplano or plateau precedes the basaltic flows of the Somún Curá plateau. The Roca Formation marine sediments are used as a guide stratum to reconstruct the uplift history of the North Patagonian Massif. It is proposed that the 100,000 km² Cretaceous planation surface of the North Patagonian Massif was uplifted in early Oligocene times, and that the 15,000 km² of basalts that erupted on its surface immediately after (Oligocene-early Miocene) may be related to the same processes that led to the uplift.