Distilling my experience in having field mapped in detail the volcanic fields at Laguna del Maule and Long Valley and having worked out their time-volume-composition magmatic histories, I compare and contrast the postglacial rhyolites of the former with six multi-vent eruptive sequences of rhyolite in California. Compilations and discussions are made of volcanic-field areas and longevities, their compositions, vent distributions, individual batch and total volumes, eruptive episodicities, and tectonic influences. Growth of long-lived pluton-scale reservoirs of granitic crystal mush, from which the rhyolite melts separated, are interpreted in terms of conceptual models I published previously—(1) fundamentally basaltic transcrustal magmatism, 1981; (2) the deep-crustal MASH zone model, 1988; and (3) the rhyolite-melt crystal-mush model, 2001. Inferences and speculations are advanced concerning processes and timescales of rhyolite-melt separation from granitic mush and of prompt or long-delayed subsequent eruption.
|Title||Comparative rhyolite systems: Inferences from vent patterns and eruptive episodicities: Eastern California and Laguna del Maule|
|Publication Subtype||Journal Article|
|Series Title||Journal of Geophysical Research|
|Record Source||USGS Publications Warehouse|
|USGS Organization||Volcano Science Center|