Repeated rhyolite eruption from heterogeneous hot zones embedded within a cool, shallow magma reservoir

Anderson, N.L., Singer, B.S., and Coble, M.A., 2019, Repeated rhyolite eruption from heterogeneous hot zones embedded within a cool, shallow magma reservoir: Journal of Geophysical Research: Solid Earth, v. 124, no. 3, p. 2582–2600. https://doi.org/10.1029/2018JB016418

The Laguna del Maule volcanic field, central Chile, was investigated in this study to determine the timing and conditions of zircon crystallization in a large, shallow, silicic magma body. By measuring zircon trace elements and U-Th ratios, the authors determined the magma reservoirs produces two episodes of rhyolitic volcanism at 23-19 and 8-2 ka. Zircon crystallization occurred over 160 kyr, over which time several hundred cubic kilometers of magma were emplaced. Their results indicate most of the volume of the reservoir existed in a relatively cold, near-solidus state during zircon crystallization, yet smaller hot zones were likely distributed throughout the reservoir containing extractible magma mush which produced the rhyolite eruptions.