Introduction -- Volcanism of Sierra Chica of Córdoba -- Volcanism of Serra Geral in Misiones Province -- Paleoreconstruction of Pangea during the Early Cretaceous volcanism in Córdoba and Misiones Provinces and its location respect to the seismic structure of the mantle -- Discussion and geodynamical proposals for the alkaline volcanism of Córdoba Province and Paraná Magmatic Province -- Conclusions.

This book analyzes the Early Cretaceous volcanic processes in Misiones Province and in Sierra Chica de Córdoba (Argentina). The volcanism in Misiones is tholeiitic and belongs to the Parana Magmatic Province (PMP), which extends throughout South America. In contrast, the volcanism in Córdoba is geographically restricted and of alkaline nature, representing a potassic locality peripheral to the PMP. To understand the causes of and geodynamic processes involved in these volcanisms, a new 40Ar /39Ar of 129.6 ± 1 Ma of a trachyte from Sierra Chica de Córdoba is presented. This dating points out that the volcanism in Sierra Chica de Córdoba slightly postdates PMP lavas. Moreover, complementary geochemical analyses from Misiones Province are presented and compared with those from the whole PMP in order to characterize its source.