Taking Yellowstone's Temperature: a New Clinopyroxene Geothermometer to Improve Timescales of Pre-eruptive Events

The goal of our research is to quantify the time period between events in the magma chamber and eruption for the Scaup Lake rhyolite lava, as it erupted after a period of quiescence similar to what Yellowstone is experiencing today. The overarching goal of studies such as this that focus on past eruptions is to provide context and statistics that will ultimately improve volcano monitoring at different types of active volcanoes. The Scaup Lake flow contains zoned minerals (e.g., feldspar, zircon, clinopyroxene) that record multiple magma injection events shortly before they were erupted. Our previous work using nano-scale elemental concentration profiles from zoned clinopyroxene (cpx) as a diffusion dating tool reinforced our hypothesis that different minerals may not record the same series of pre-eruptive events, and that cpx crystal rims record older events in the Scaup Lake flow (on the order of 100s of years prior to eruption [Brugman et al., AGU OSPA talk, 2016]) than do feldspar rims (< 10 months and 10-40 years prior to eruption [Till et al., Geology, 2015]). In light of new temperature data, we have updated our diffusion dating results to better quantify pre-eruption timescales at Yellowstone.