Geology Commons^™

Post-Fire Erosional And Hydrological Processes Promoting Debris Flow Initiation In A Douglas Fir And Western Hemlock Forest In The Riverside Burn Area, Oregon, Morena Nicole Hammer

Dissertations and Theses

Post-fire debris flows initiated by overland flow in the Pacific Northwest (PNW) are largely undocumented. Instead, debris flows are typically initiated by shallow landslides that result in a mud slurry of water and sediments traveling downhill under the force of gravity. However, because of the Fall 2020 fires in Oregon, the typical initiation style and erosional patterns in burned catchments may have changed because of unusually high burn severity. Due to the intensity of these fires, we set out to determine how hydrologic processes and erosion occurred, when they occurred, and what process was primarily responsible for the erosion that …

Reassessing Hydrothermal Heat Discharge And The Relationship Of Hot Springs In The North Oregon Cascades, Aaron Alexander Orr

Dissertations and Theses

Reservoir temperatures of hydrothermal systems in the Pacific Northwest reflect the feasibility of geothermal energy production and the tectonic framework of the region. Multicomponent geothermometry techniques were applied to new and historic water chemistry data in the north-central Oregon Western Cascades and the lower Wind River Valley in southern Washington in order to recalculate reservoir temperatures. Revised reservoir temperatures, water chemistry, and isotope data were used to determine relationships between hot springs in the north-central Oregon Cascades. Geothermal reservoir temperatures were estimated for the lower Wind River Valley (98.44 ± 0.96°C) and for Austin and Bagby Hot Springs (100.10 ± …

Electrical Conductivity And Resistivity Study Of Heterogeneous Sediment In Inwood Hill Park, Manhattan, Ny, Rea A. Khaleda

Dissertations and Theses

The area near the inlet of Spuyten Duyvil Creek in Inwood Hill Park in New York City exhibits complex hydrological processes. The inlet is a tidal flat, which contains brackish water; a mixture of saltwater and freshwater. The area was modified by man, built on a shell bed and contains heterogeneous sediment. One field adjacent to the inlet contains several small sinkholes. Electrical resistivity and ground conductivity techniques were used in order to get an understanding of the hydrological processes of this field. It was hypothesized that the formation of the sinkholes is due to the tidal forcing of the …

Hydrogeologic Investigation Of A Pumice Aquifer, Fremont/Winema National Forest, Oregon, Jonathan Michael Weatherford

Dissertations and Theses

The middle Holocene cataclysmic eruption of Mount Mazama blanketed Walker Rim, in south central Oregon, with 270 cm to 300 cm of pumice, causing capture of surface water systems by groundwater, stream relocation, and the formation of biologically diverse fens and seasonal wetlands. The pumice aquifer at Round Meadow, an 8.6 km² basin, hosts both a fen and seasonally ponded wetlands. The Round Meadow watershed lies within a closed basin between the upper Klamath and Deschutes river basins. As the highest meadow at Walker Rim, it is a relatively well-constrained system to study the effects of hydrological disruption.

A …

Characterization Of The Shallow Subsurface Geohydrology Of The Ni-Les'tun Unit On The Bandon Marsh National Wildlife Refuge, Christopher Madison Beard

Dissertations and Theses

The Bandon Marsh is a large marsh restoration project located in southwest Oregon. The land has been previously used for dairy farms and much of the marsh was used for cattle grazing. The goal of the restoration is to recreate a natural habitat for shorebirds and fish. The purpose of this thesis is to gather and analyze data on the geology of the marsh and both ground and surface water quality to evaluate its ability to support biology.

The US Fish and Wildlife Service began restoration on the Bandon marsh in 2005. Research on the Ni-les'tun Unit began in that …

Hydrogeologic Characterization Of Dutch Canyon, Scappoose, Oregon, Derrick Lee Wagner

Dissertations and Theses

Dutch Canyon is located directly west of the City of Scappoose in Columbia County Oregon. This area is proximate to Highway 30, a major access corridor to downtown Portland, and is experiencing a population increase, which is expected to continue and likely accelerate. As a result, there is growing pressure on water resources. Individual and community efforts to utilize groundwater resources have been hampered by generally poor groundwater yields and water quality concerns outside of the Columbia River corridor and a lack of published hydrogeologic information for the region.

The intent of this study is to identify the water-bearing units …

Investigations Into The Regional And Local Timescale Variations Of Subglacial Drainage Networks, Justin Hiester

Dissertations and Theses

Subglacial water plays an important role in the regulation of an ice sheet's mass balance. It may be the dominant control on the velocities of ice streams and outlet glaciers on scales of months to millennia. Recent satellite observations of ice surface elevation changes have given researchers new insights into how subglacial water is stored and transported. Localized uplift and settling of the ice surface implies that lakes exist beneath the ice sheet that are being filled and drained on relatively short time scales. %At the base of an ice sheet water can be transported through a variety of drainage …

In Situ Hydraulic Testing And Water Quality Sampling In The Hyporheic Zone Of The Columbia River, Hanford Reach, Washington, Evan V. Arntzen

Dissertations and Theses

Several chemical and radiological contaminants are present in an unconfined aquifer underlying the U.S. Department of Energy's Hanford Site in southeast Washington State. Hexavalent chromium [Cr(VI)], previously used as an anticorrosive in plutonium production reactors on the shoreline of the Columbia River, is of particular concern because of its conservative nature, toxicity to humans and aquatic life, and proximity to protected salmon spawning habitat. Hydrogeologic data are abundant from the unconfined aquifer, but are lacking from the hyporheic zone through which Cr(VI) is transported into the river. A hydrogeologic study was conducted near one known Cr(VI) plume to determine the …

Interpretation Of The Thermal Behavior Of Groundwater In An Alluvial Terrace : Bonneville Dam, Columbia Gorge, Oregon, Richard Stephen Malin

Dissertations and Theses

Groundwater temperature data, collected at an alluvial terrace located on the Oregon shore of the Columbia River downstream from Bonneville Darn, was analyzed in order to characterize and formulate a conceptual model of the thermal data for the groundwater system in the terrace. There is concern that an unlined entrance channel for a new navigation lock, to be located down the middle of the terrace, will widen the range of temperatures in the fish hatchery-groundwater supply. The analysis of temperature behavior in the terrace supports the hydraulic observations derived from analysis of pump test data, but with greater definition of …

Analysis And Numerical Simulation Of The Ground Water System At The Bonneville Navigation Lock Site, Oregon, Dirk Baron

Dissertations and Theses

As part of the new navigation lock for Bonneville Dam a new water source for the Bonneville Fish Hatchery must be supplied. The hatchery is located on the Oregon side of the Columbia River downstream of the dam. It requires large quantities of water free from chemical and biological contamination. In addition, the water has to be in a narrow temperature range. Currently the fish hatchery receives its water from a well field that is located on the alluvial terrace downstream of Bonneville Dam. The well field lies in the proposed approach channel for the new lock and has to …

A Groundwater Flow Model Of The Aquifer Intercommunication Area, Hanford Site, Washington, Elizabeth Gail Simkover

Dissertations and Theses

Intercommunication has been identified between the unconfined and uppermost confined aquifer systems underlying a portion of the U.S. Department of Energy's Hanford Site. Erosional thinning and fracturing of the basalt confining layer within the study area allows physical contact between the two aquifers, but the vertical hydraulic gradient (a required driving force) is small. To better conceptualize the distribution and volume of the leakage occurring between the aquifer systems, this study investigates the confined Rattlesnake Ridge Aquifer flow system, which appears to be more sensitive to the vertical leakage than the overlying unconfined aquifer.

The Geology, Geochemistry, And Alteration Of Red Butte, Oregon: A Precious Metal-Bearing Paleo Hot Spring System, Carol Susan Evans

Dissertations and Theses

Red Butte is located 60 km south of Vale, Oregon, about 20 km west of the Oregon/Idaho border. The butte is within the Owyhee Upland physiographic province of eastern Oregon which lies at the intersection of the Western Snake River Plain, the High Lava Plains, and the Northern Basin and Range provinces.

The butte is composed of Miocene to Pliocene lacustrine and fluvial volcaniclastic sediments. The topography of the butte is controlled by silicification of the sandstones and mudstones which cap it. Silicification and hydrothermal alteration are both structurally and stratigraphically controlled. North-trending normal faults dominate the area, and show …

The Geology And Hydrothermal Alteration Of The Bear Creek Butte Area, Crook County, Central Oregon, Richard Matthew Wilkening

Dissertations and Theses

The Eocene Clarno Formation, the Oligocene John Day Formation and basalts of the High Lava Plains are exposed in the Bear Creek Butte area in Central Oregon. In this area the Clarno Formation can be divided into a lower sequence composed of intermediate lava flows with intercalated mudflows and volcaniclastic sediments and an upper sequence of rhyolite and basalt flows and felsic ruffs. Separating the two units is a well developed saprolite. The change from intermediate to rhyolite-basalt volcanism reflects a change in the tectonic environment of the Cascade volcanic arc from compression to relaxation as subduction of the Farallon …