CONNECTING HIGH-SILICA, RHYOLITE-HOSTED PHENOCRYSTS TO POTENTIAL CRYSTAL MUSH INTRUSIVE COMPLEMENTS: INSIGHTS FROM BAITOUSHAN VOLCANO AND VALLES CALDERA

High-silica rhyolites are the volcanic expression of large scale, high silica igneous systems. It is currently unclear as to how these extrusive products, which can be characterized by enormous volumes and highly devastating eruptions, are connected to their intrusive counterparts. Zircon studies, commonly undertaken on such high silica systems, suggest complex intrusive histories marked by multiple episodes of magmatic activity spanning variable time periods as reflected by wide-ranging ages inherited during zircon growth, potential dissolution, and regrowth. Whether such systems can be connected to their intrusive counterparts critically depends on evaluating the components that comprise the extrusive materials erupted at the surface. The greatest potential for such connections lie in techniques that evaluate these components at a microanalytical scale. As a result of advances in techniques and technologies, single grain and sub-grain sampling can be used to evaluate and constrain the properties of associated, non-erupted plutonic materials that are genetically connected to these extrusive bodies. In this light, we present results from two on-going studies targeting single crystals in pantellerites and comendites from Baitoushan volcano (N. Korea/China) and from high-silica rhyolites from Valles caldera. Mineral components in these systems offer insights into the magma sources and the processes involved in rhyolitic magma assembly. Extrusive materials from these two sites also demonstrate both subtle and extreme variations in the intrusive counterparts that are associated with large scale rhyolitic eruptions.