Clinopyroxene Crystals in Basic Lavas of the Marsili Volcano Chronicle Early Magmatic Stages in a Back-Arc Transcrustal Mush System

Constraining the pre-eruptive processes that modulate chemical evolution of erupted magmas is a challenge. An opportunity to investigate this issue offered by interrogation crystals carried in lavas. Here, we employ clinopyroxene from back-arc lavas order identify driving basalt andesite magma within transcrustal plumbing system. The assembled archive reveals mantle melts injected at crust-mantle transition cool and crystalize, generating clinopyroxene-dominated mush capped melt-rich domain. Magma extracted deep storage zone fed eruption basaltic In addition, chemically evolved rapidly rising briefly stalled shallow crustal levels, sourcing crystal-poor Over time, hot ascending primitive intercepted mixed with shallower cooling bodies forming hybrid basic blended cargoes these provide evidence for hybridization, which undetectable whole-rock perspective, as mixing involved similar magmas. heterogeneity found unusual since it provides, first complete set mush-related scenarios evolve compositions. Neither chemistry alone nor record mineral phases crystallizing subsequent can insights on such early magmatic processes. obtained be used template interpretation preserved elsewhere, giving into dynamics feeding system are lost when using chemistry.