Magmatic addition rates differentiate periods of steady-state versus flare-up magmatism in the Central Andean arc

Abstract Cordilleran arcs are built by long periods of steady-state magmatism punctuated transient high-flux magmatic episodes or flare-ups. Such flare-ups, manifested as prodigious silicic volcanism and magmatism, result from geodynamic perturbations that cause elevated rates magma addition to the crust. Questions remain, however, about how quantitatively compare between flare-up modes arc after major perturbation begins. Here, we compute new estimates erupted volumes over last 35 Myr for 22.5–29°S segment Central Andes based on a volcanic geospatial database. These yield at least an order magnitude higher during compared conditions. A lag time ~8–12 ocean ridge subduction (the in Andean arc) onset conditions is estimated.