Journal of Undergraduate Research


trace element analysis, quartz grains, Wah Wah Springs, granodiorite intrusion


Physical and Mathematical Sciences


Geological Sciences


The Wah Wah Springs tuff and cogenetic granodiorite were part of the creation of the Indian Peak-Caliente Caldera Complex, which lies on the Nevada-Utah border (Skidmore, 2013). The complex formed during the middle Cenozoic (36-18 Ma) during an episode of explosive silicic activity (Best et al., 2013). Rollback of the subducting lithosphere likely caused the silicic activity, evidenced by the migration of magmatism southward (Best et al., 2013). The dehydration of the subducting oceanic lithosphere caused mafic magmas high in water to rise and fractionate in continental crust before eruption (Skidmore, 2013). Over twenty-four different ignimbrites have been found in the Indian Peak complex, with the largest ash flow spreading 150 km from the complex (Best et al., 2013). The eruptions include the Lund Tuff (29.0 Ma), the Cottonwood Wash Tuff (30.9 Ma), the Wah Wah Springs (30.0 Ma) and many others (Best et al., 2013). The Wah Wah Springs eruption expelled an estimated 5,900 cubic kilometers of material, making it the largest of these eruptions and exceeding the size of the largest Yellowstone eruptions (Best et. al. 2013).