Erupciones hidromagmáticas en el volcanismo cuaternario de Olot (Girona)

Abstract

This paper makes clear the importance of the explosive volcanism in the field of the quaternary volcanism of Girona, especially in Olot area where the most recent episodes are concentrated. Fourteen volcanic cones undergoing sorne phreatomagmatic or phreatic explosive phases during their evolution have been identified. The hydromagmatic activity gives rise to a wide variety of pyroclastic deposits, whose study has enable to distinguish several eruptive sequences in these volcanoes. The differences of explosive behaviour among the different kinds of volcanoes are due, basically, to the different ways of water/magma interaction in each volcano, which are determined by the geological structure of the last hundreds of metres of the crust and, especially, by the hydrogeological features of the ground.