Portland State University PDXScholar Dissertations and Theses Dissertations and Theses Winter 4-10-2018 Areal Extent and Volumes of the Dinner Creek Tuff Units, Eastern Oregon Based on Lithology, Bulk Rock Composition and Feldspar Mineralogy Teresa Rae Hanna Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Geology Commons, and the Volcanology Commons Let us know how access to this document benefits ou.y Recommended Citation Hanna, Teresa Rae, "Areal Extent and Volumes of the Dinner Creek Tuff Units, Eastern Oregon Based on Lithology, Bulk Rock Composition and Feldspar Mineralogy" (2018). Dissertations and Theses. Paper 4346. https://doi.org/10.15760/etd.6239 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible:
[email protected]. Areal Extent and Volumes of the Dinner Creek Tuff Units, Eastern Oregon Based on Lithology, Bulk Rock Composition and Feldspar Mineralogy by Teresa Rae Hanna A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geology Thesis Committee: Martin J. Streck, Chair Robert Perkins John Bershaw Portland State University 2018 ABSTRACT The Dinner Creek Tuff erupted during a period of rhyolitic volcanism coeval to the flood volcanism associated with the Columbia River Basalt Group. The High Rock Caldera Complex, Lake Owyhee and McDermitt volcanic fields account for ~90% of the rhyolites erupted between 16.7-15.0 Ma. Situated at the northern end of the Lake Owyhee volcanic field, the Dinner Creek Tuff was originally mapped as a ~2,000 km2 single ignimbrite confined to the Malheur Gorge.