Presencia de cenizas y lapilli esferoidales con estructura interna concéntrica (i.e. pelletal lapilli o spinning droplets) en la tefra del volcán Cabezo Segura (Región Volcánica de Calatrava, Ciudad Real)

Abstract

The Cabezo Segura volcano is located in the central part of the Calatrava Volcanic Province. Some deposits of this volcano are formed by singular spherical lapilli and bombs. These lapilli and bombs are the result of welding of ash and fine-grained lapilli droplets (< 4mm) of olivine melilitite composition, spherical morphology and a cored and concentric inner structure. This pattern is similar to that of pelletal lapilli and spinning droplets which appear commonly in kimberlitic, kamafugitic, and carbonatitic pipes. The origin of these peculiar pyroclasts could be related to the fragmentation of a low viscosity magma through magmatic volatile exsolution and the subsequent rotation of magma droplets during ascent within a fluidized system