Multi-stage magma mixing in the pre-caldera series of Fuego de Colima volcano

Abstract

Mineralogical and geochemical data from pre-caldera lavas of Volcán Fuego de Colima indicate that both fractional crystalization and mixing processes occurred together. Three types of mixing are evidenced: (i): Mixing between fresh input of mafic magma and olivine-clinopyroxene cumulates in the lower part of the magma chamber. (ii): Mixing, within the shallow chamber, between this deep juvenile magma (previously differentiated by crystal fractionation or not, ol-cpx enriched or not in an deeper magma chamber) and a differentiated magma, andesitic or dacitic in composition. (iii): mixing by convection between magmas previously differentiated by mixing and/or crystal fractionation at different levels in the magma chamber.