Long-lived dacitic magmatic systems and recharge dynamics in the Jemez Mountains volcanic field, western USA

Abstract We examine the connected history of dacite-dominant volcanic rocks Tschicoma Formation, erupted between 5.5 and 2 Ma from Jemez Mountains field, western USA. Zircon samples two separate eruptions have continuous SHRIMP U–Pb age spectra spanning 0.84–1.08 Myr duration (3.12–3.96 3.50–4.58 Ma, respectively), following an episode zircon crystallization 0.28–0.50 earlier (at 4.46 4.86 respectively). chemical variations, as well ubiquitous resorption textures that commonly show large core-rim differences (up to 720–740 kyr), suggest they grew in melt lenses. Zircons were likely stored at near-solidus or even sub-solidus conditions after crystallization, but may been reactivated response least four major magma recharge events every 300–400 kyr smaller between. A cycle dissolution (from heating), recrystallization (during cooling), storage repeated different locations mush system throughout its lifespan; each recharge-induced heating stage last for several hundred more than a thousand years based on calculations dissolution. envisage lenses be distributed crystal zone, coalescing into single batch occurs shortly before eruption. Once active, increasing supply rates trigger large-scale partial melting pre-existing caldera-forming eruptions.