CENOZOIC INTRAPLATE VOLCANISM RELATED TO EXTENSIONAL TECTONICS AT CALATRAVA, CENTRAL IBERIA

The Calatrava Volcanic Province is characterized by an intra-plate alk aline undersaturated magmatic association of melilitites, nephelinites , alkali olivine basalts and leucitites that were extruded in the cent ral Iberian Peninsula (Spain) during Late Miocene-Quaternary time. Thi s volcanism can be related to the following two-stage scenario: (1) an initial mantle-diapir stage, during which magma generation would have occurred at the lithosphere/asthenosphere boundary triggering minor a ccumulation processes at the crust/mantle interface, and consequent we akening/extension of the upper crust; and, (2) a final indentation sta ge related to disruption effects caused by the tectonic welding of the Prebetic Arc onto the Iberian foreland.