Magmas in collision: Rethinking chemical zonation in silicic magmas

The heterogeneity of eruptions attributed to protracted fractionation in su bvolcanic magma chambers may instead result from chamber recharge. The case of mafic magma intruding andesitic slush is recognized as giving rise to h ybrid effusive eruptions such as at Unzen volcano, Japan, and Soufriere Hil ls volcano, Montserrat. We propose that zoned andesite-rhyolite explosive e ruptions are the complement to mafic recharge, where the resident magma is also andesitic but the intruding magma is silicic.