The primary goal of this study is to assess the impact of a subduction component
added to the mantle wedge beneath the Oregon Cascades to the composition and fO2 of
primitive Cascade basalts. Olivine-hosted melt inclusions from compositionally diverse
basalts across the Cascade arc (~100 km) are utilized in an...
Magmatic sulfides from Yerington, Nevada, and Yanacocha, Peru, were analyzed by laser ablation-inductively coupled mass spectrometry (LA-ICPMS) and electron microprobe to determine copper, gold, and silver concentrations and ratios in order to examine the relationship to the metal content of related magmatic-hydrothermal ores. The magmatic sulfides occur in plutonic rocks...
This thesis develops a geology training manual for the Interpretation staff of Craters of the Moon National Monument and Preserve (CRMO) in southern Idaho. The manual will help the staff convey geologic principles to park visitors who are experiencing a landscape formed by volcanic processes. Basic geology and the most...
Plate boundaries are commonly regions of complex, diffuse deformation with
the motion across the boundary accommodated by numerous structural systems, rather
than being narrow, discrete zones of deformation. One such boundary occurs where
the North American plate makes contact with Juan de Fuca, Gorda, and Pacific plates
along the west...
Several different petrological techniques have been applied to lava flows between
200 to 475,000 years old from Mount Hood, Oregon. Mount Hood is unusual, in comparison to nearby Mount St. Helens and Mount Jefferson, in that it has produced relatively homogeneous lava compositions over 475,000 years. Erupted lavas are mostly...
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Cristina M. Darr, Author
ACKNOWLEDGMENTS
I would like to thank Adam Kent, Anita
The northwestern corner of the Basin and Range Province (NWBR) lies in southeast Oregon where extensive Late Miocene, mafic to bimodal basalt-rhyolite volcanism and extensional faults dominate a stark and arid landscape. Near Lake Abert, the Late Miocene volcanic section abuts Early Miocene, dominantly intermediate composition volcanoes at the Coleman...
Biological control is the action of predators, parasitoids, or pathogens to maintain
a pest organism's population at lower numbers than would occur in the absence of the
agent. Entomopathogenic nematodes can be used as biological control agents for insect
pests. These nematodes infect insects and release a toxic bacterium that...
An ASR metric and site rating index applied to over 120 municipal and agricultural locations across Oregon, combined with comparison to case study data from existing ASR sites, indicate that more than 50% of selected sites are hydrogeologically suitable for ASR. The ASR metric is a ratio of aquifer storage...
This research incorporates geochemical and helium isotopic analyses of Lau Basin volcanic glasses, along with helium isotopic analyses of water column hydrothermal plumes to better understand the processes that control the formation and evolution of this backarc basin. Lavas newly collected from the four southernmost segments of the Valu Fa...
Methane flux was measured from northern Alaska Arctic Coastal Plain wetlands to assess the spatial and temporal variability of Arctic tundra emissions during the summers of 1987 through 1990. Initially, the role of vegetation in the release of methane from substrate to atmosphere was assessed. Methane emissions were shown to...