Title: Silicic Volcanism at the Northern and Western Extent of the Columbia River Basalt Rhyolite Flare-up: Rhyolites of Buchanan Volcanic Complex and Dooley Mountain Volcanic Complex, Oregon
Abstract: Two mid-Miocene (16.5-15 Ma) rhyolite volcanic centers in eastern Oregon, the Buchanan rhyolite complex and Dooley Mountain rhyolite complex, were investigated to characterize eruptive units through field and laboratory analysis. Results of petrographic and geochemical analysis add to field observations to differentiate and discriminate the eruptive units. Additionally, new geochemical data are used to correlate stratigraphically younger and older basalt and ash-flow tuff units with regional eruptive units to constrain the eruptive periods with modern Ar-Ar age dates.