Petrology of the Coyaguayma ignimbrite, northern Puna of Argentina: Origin and evolution of a peraluminous high-SiO2 rhyolite magma

► The Coyaguayma ignimbrite is a SiO2-rich rhyolite from N Puna (central Andes). ► It has stable peraluminous minerals (Al-rich biotite, garnet and sillimanite). ► Magma containing 4-5% H2O crystallized at P = ~ 4-5 kbar and T = 800-720 °C. ► Composition is modeled via contamination and fractionation of dacitic Puna magmas. ► Model may be used to explain peraluminous magmas in Andean-type arc settings.