Linking magmatic processes and magma chemistry during the post-glacial to recent explosive eruptions of Ubinas volcano (southern Peru)

摘要: Abstract Understanding the links between magma differentiation processes, plumbing system and composition at arc volcanoes is of paramount importance for volcanic hazard assessment. In this work we focus on post-glacial, Holocene, historical, recent eruption products Ubinas volcano (Peru), which display an overall decrease in silica content from older, plinian (VEI 3–5), rhyolitic eruptions (69–71 wt% SiO2) to historical (2006–2009, 2013–2017), vulcanian 1–2) basaltic andesitic (55–57 wt% SiO2). Based a comprehensive study major trace elements Sr-Nd-Pb isotopes, conclude that temporal pattern reflects evolution magmas middle-to-upper crust by coupled Assimilation-Fractional Crystallization (AFC) process involving cumulate composed plagioclase, amphibole, clinopyroxene, orthopyroxene Fe–Ti oxides, with minor amounts olivine biotite mafic felsic end-members, respectively. Upper crustal assimilation limited 5–8 vol%, but radiogenic signature requires larger component, must therefore occur middle lower depths. The petrology also points increase P-T conditions: large Holocene dacitic record temperatures ranging 800 850 °C pressures range 200–400 MPa, whereas 2013–2017) provide higher (1000 °C, >300–400 MPa). Overall, thermo-barometry, phase equilibrium geochemical constraints allow us propose existence column highly crystalline mush containing batches liquid magma, seems be continually recharged deeper levels. On basis petrological nature (1667 CE, 2006–2009, postulate during last centuries, experienced recharge-dominated process, no evidence rejuvenation silica-rich reservoir fed eruptions. This highlights detailed studies sequences explosive order constrain magmatic processes conditions control