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Full-Text Articles in Physical Sciences and Mathematics

The Role Of Cumulate Plagioclase Entrainment In The Steens Basalt, Se Oregon: Insights From The Magma Chamber Simulator, Valerie Strasser Jan 2020

The Role Of Cumulate Plagioclase Entrainment In The Steens Basalt, Se Oregon: Insights From The Magma Chamber Simulator, Valerie Strasser

All Master's Theses

The Steens Basalt, located in SE Oregon, is the oldest and most mafic member of the Columbia River Basalt Group (CRBG). Because the Steens Basalt contains large (up to 6 cm) and abundant (up to 40%) plagioclase crystals, it is classified as a Giant Plagioclase basalt (GPB). Understanding the origin of these giant plagioclase yields insight into magmatic processes like recharge, crustal assimilation, cumulate entrainment, and fractional crystallization. Because large and abundant plagioclase are found in other flood basalt provinces worldwide, these results could also enhance understanding of magma evolution and storage conditions for GPB worldwide. The Steens basalt is …


Late Holocene Paleoflood Hydrology Of The Snake River In The Lower Hells Canyon, Idaho, Kent C. Allen Jan 2020

Late Holocene Paleoflood Hydrology Of The Snake River In The Lower Hells Canyon, Idaho, Kent C. Allen

All Master's Theses

The Snake River watershed spans a large geographic region from the Rocky Mountains to the inland Pacific Northwest, and a comprehensive paleoflood chronology on the mainstem of the river is key to identifying the frequency and magnitude of large prehistoric floods within the region. We examined and compared four sites of slackwater deposits along a 20-km reach of the Lower Hells Canyon on the Snake River, Idaho. The sites contain evidence of up to 34 paleofloods within the last 1700 years. Stratigraphic breaks, soils, and in-situ plant or archaeological materials demarcate distinct layers that represent discrete paleoflood events. Radiocarbon dates …


Distribution Of Invasive Plant Species On Debris Cones At Mount Rainier National Park, Shaun Morrison Jan 2020

Distribution Of Invasive Plant Species On Debris Cones At Mount Rainier National Park, Shaun Morrison

All Master's Theses

Invasive plant populations within Mount Rainier National Park are a biological and ecological threat to the unique mountain landscape. A better understanding of their distribution and transport within the landscape is needed to improve invasive species monitoring for National Park Service management. This study investigates how invasive plant populations in Stevens Canyon are utilizing the debris cone disturbances and associated geomorphic processes to facilitate movement within the park. Vegetation transects were performed along Stevens Canyon Road (to observe the roadside community composition) and on the debris cone features (to observe species movement from the roadside). These vegetation observations are presented …


Modeling Cle Elum Reservoir Shoreline Erosion: Gis Analysis To Support Cultural And Environmental Resource Management, Yakima Basin, Washington, Michael H. Horner Jan 2020

Modeling Cle Elum Reservoir Shoreline Erosion: Gis Analysis To Support Cultural And Environmental Resource Management, Yakima Basin, Washington, Michael H. Horner

All Master's Theses

In the Yakima Basin, managers are expanding reservoirs including Cle Elum Lake to increase the availability of water. The objective of this study was to examine areas prone to further shoreline erosion to inform resource management. This research included the use of airphotos and fieldwork to identify erosional shorelines. Erosion was verified in the field using a video survey as well as indicators such as shoreline slope, sediment size, and nearshore width. Near-term erosional segments were identified by more rapidly receding bluffs while long-term erosional segments included both bedrock cliffs and bluffs. Although most of the shoreline is depositional, near-term …