Geology Commons^™

The Long-Term Viability Of A Zero-Valent Iron Permeable Reactive Barrier, Stuart Cowburn

Dissertations and Theses

Zero-valent iron permeable reactive barriers (PRB's) hold significant potential as a tool for groundwater remediation. Uncertainties remain, however, as to the effective lifetime of Fe⁰ barrier technology under full-scale operational conditions. Potential limits on barrier lifetime include reductions in permeability due to clogging by precipitates and oxidation of all Fe⁰ prior to the exhaustion of the contaminant source.

A 46 m long, 0.6 m wide, and 7.3 m deep Fe⁰ PRB was installed at the US Coast Guard Support Center, Elizabeth City, NC, in June 1996. The barrier was designed to remediate groundwater principally contaminated with Cr(VI) …

Hydrogeology And Paleohydrology In The Williamson River Basin, Klamath County, Oregon, Jeffrey Scott Conaway

Dissertations and Theses

Stress on the water resources of the Williamson River basin has led to their regulation to protect important habitat. Quantification of this resource is required for accurate regulation. A portion of this study is a hydrogeologic reconnaissance that suggests directions for future work. Measured discharge and deuterium isotope data from points above and below the Williamson River canyon indicate that the river receives 99% of its discharge from ground water during periods of low flow. The principle aquifer of the southern Klamath Marsh is a fractured basalt, while continental sediments that are up to 200 m thick provide high artesian …

A New Numerical Model Of Coupled Inland Ice Sheet, Ice Stream, And Ice Shelf Flow And Its Application To The West Antarctic Ice Sheet, Christina L. Hulbe, D. R. Macayeal

Geology Faculty Publications and Presentations

We have developed a dynamic/thermodynamic finite element numerical model that couples inland ice sheet, ice stream, and ice shelf dynamics. This new model stands apart from other whole ice sheet models in its explicit treatment of ice stream flow. Additionally, the model accounts for both horizontal and vertical advection and diffusion of temperature in the flowing ice. In present day simulations of the West Antarctic Ice Sheet (WAIS), modeled ice velocity agrees well with observed ice flow. In particular, the model reproduces the pattern of speed variation across ice streams although the continuous downstream speed up of ice flow cannot …

Engineering Geology And Relative Stability Of The Southern Half Of Newell Creek Canyon, Oregon City, Oregon, William J. Burns

Dissertations and Theses

This study investigates the engineering geology and relative slope stability of the southern half of Newell Creek Canyon, Oregon City, Oregon, located partially inside the urban growth boundary of Portland where there is increasing pressure for development in areas of geologically hazardous terrain.

Within the study area, features associated with landslides were mapped and categorized according to their relative age (active, inactive-young, and inactive-mature) and the depth to the failure plane (deep or shallow-seated). These features were then examined and 79 landslides were identified. Sixty-five of the slides were classified as shallow-seated or having a failure plane ≤ 4.5 meters …

High Resolution Seismic Reflection Interpretations Of The Hood Canal-Discovery Bay Fault Zone, Puget Sound, Washington, Brian J. Haug

Dissertations and Theses

The north-northeast trending Hood Canal is an elongate 75 km long, 2-5 km wide, maximum 190 m deep glacial trough that represents the western limit of Washington's Puget Sound estuary complex and eastern boundary of the Olympic Peninsula. Airgun seismic reflection data were collected in Hood Canal April 4-5, 1994 onboard the University of Washington's R. V. Thomas G. Thompson for the purpose of defining the enigmatic and relatively unstudied Hood Canal-Discovery Bay fault zone (HDF). This fault zone parallels western Hood Canal, is obscured by marine waters and thick late Quaternary glacio-marine sediments, and is defined locally by gravity …

Comparison Of Ice-Shelf Creep Flow Simulations With Ice-Front Motion Of Filchner-Ronne Ice Shelf, Antarctica, Detected By Sar Interferometry, Christina L. Hulbe, Eric Rignot, D. R. Macayeal

Geology Faculty Publications and Presentations

Comparison between numerical model ice-shelf flow simulations and synthetic aperture radar (SAR) interferograms is used to study ice-flow dynamics at the Hemmen Ice Rise (HIR) and Lassiter Coast (LC) corners of the iceberg-calving front of the Filchner-Ronne Ice Shelf, Antarctica. The interferograms are constructed from SAR images provided by the European Space Agency's remote-sensing satellites (ERS-lj2). Narrow bands of large shear strain rate are observed along the boundaries between fastflowing ice-shelf ice and no-flow boundaries. Large rifts, opened where the ice shelf separates from the coast, appear to be filled with a melange of sea ice, ice-shelf fragments, and snow. …

Morphology, Eruption Rates, And Rheology Of Lava Domes: Insights From Laboratory Models, Jonathan H. Fink, Ross W. Griffiths

Geology Faculty Publications and Presentations

The growth of lava domes can be either quiescent or violent, with transitions between styles of behavior commonly occurring with little warning. Here we propose that the behavior depends on the eruption rate, the magma rheology, and the thickness ofthe cooling surface. We present a model, based on laboratory simulations, field measurements, and photographic analysis, that relates the morphology and texture of a dome to the thickness of its cooled carapace, and thence to eruption conditions. A sequence of four main types of dome (spiny, lobate, platy, and axisymmetric) is identified in laboratory analog experiments with a Bingham plastic. These …

An Ice Shelf Mechanism For Heinrich Layer Production, Christina L. Hulbe

Geology Faculty Publications and Presentations

The effect of an ice shelf in the Labrador Sea on ice-rafted sediment delivery to the glacial North Atlantic is investigated using a finite element numerical model of ice shelf flow. Discharge into the shelf from Hudson Strait creates a thick central core, extending downstream into the shelf, that is flanked by relatively thin ice. Melting at the base of the deep keel would produce cool, fresh water which would rise to refreeze along the keel's flanks. Debris deposited by melting deep central ice could create the Heinrich layers observed in the Labrador Sea while the debris-rich ice protected by …

Geologic Evidence Of Historic And Prehistoric Tsunami Inundation At Seaside, Oregon, Brooke K. Fiedorowicz

Dissertations and Theses

Over the past decade, research conducted along the Cascadia subduction zone coast established evidence for coseismic subsidence, liquefaction, and nearfield tsunami deposition. Seaside is a low lying northern Oregon coastal city potentially at risk for nearfield tsunami inundation from a Cascadia earthquake. The 1964 Alaskan farfield tsunami impacted Seaside, and deposits from that event serve as a model for interpreting prehistoric tsunami deposits in the Seaside area. A reconnaissance subsurface study of potential tsunami inundation sites was performed by trenching and gouge coring in the coastal wetlands along the Necanicum River, Neacoxie Creek, drainage to the east of Neacoxie Creek, …

Researchers Pool Knowledge About Antarctic Dry Valleys, Andrew G. Fountain, Sarah Spaulding

Geology Faculty Publications and Presentations

Most of us think of ice when we think of the Antarctic, and rightly so, considering that only 5% of it is ice-free. Dry valleys--the ice-free areas--have sandy, rocky valley floors, ice-covered lakes, and streams that flow only two months of the year. The McMurdo Dry Valleys (78øS 163øE) are the largest of these regions.

Geochemistry, Stratigraphy And Provenance Of The Portland Hills Silt In The Tualatin Mountains, Portland, Oregon, John L. Lawes Iii

Dissertations and Theses

Soil morphology and geochemistry of loess were investigated at nine sites in the Tualatin Mountains west of Portland and at additional sites in The Dalles, eastern Washington and Puget Sound. A total of forty samples were examined using Instrumental Neutron Activation Analysis (INAA).

Stratigraphic relationships and soil development suggest that the PHS ages of Lentz (1977) be revised. The age of the Portland Hills Silt (PHS) ranges from 12,000 to at least 960,000 years before present.

The geochemistry of the PHS supports the Lentz (1977) hypothesis of the PHS as a loess of continental origin. Thorium/scandium ratios in the PHS …

Early To Middle Pleistocene Catastrophic Flood Deposits, The Dalles, Oregon, David Irving Cordero

Dissertations and Theses

A roadcut on Highway 197, three kilometers southeast of The Dalles, Oregon, exposes a sequence of Quaternary sediments and five buried paleosols. The sediments, paleosols, and associated tephras at this site provide evidence of a Quaternary history of catastrophic flooding in the Columbia Basin extending back at least 700 ka and of an early eruption (ca. 600 ka) of Mount Adams. Four sedimentary units are exposed in this cut: Holocene loess, late Wisconsin Missoula Flood slackwater deposits, five pre-late Wisconsin catastrophic flood slackwater deposits bearing well developed paleosols, and late Tertiary Dalles Formation volcaniclastics. All but the oldest are predominantly …

Post-Middle Miocene Geologic History Of The Tualatin Basin, Oregon With Hydrogeologic Implications, Doyle Coley Wilson

Dissertations and Theses

The geologic history and sedimentary till of the Tualatin Basin after Columbia River Basalt Group (CRBG) emplacement is assessed and related to groundwater characteristics. The 334 m deep HBD-1 core from the Hillsboro Airport, provides the primary information for sediment characterization and is supported by over 2400 well logs and cores, and four seismic lines. The sedimentary section above the 26 m thick paleosol on the CRBG in HBD-I is divided into two main groups: a 25 m thick section of Missoula flood sediments called the Willamette Silt overlies a 263 m thick finegrained sequence of fluvial Neogene sediments.

Pollen, …

Geochemical Characteristics And Correlations Within The Triassic-Jurassic Age Gabbs And Sunrise Formations Of West Central Nevada, Karen Elizabeth Boelling

Dissertations and Theses

Trace and minor element geochemistry was determined using Instrumental Neutron Activation Analysis for ninety-six (96) limestone and calcareous siltstone samples from four stratigraphic sections in the Triassic-Jurassic age Gabbs and Sunrise formations of west central Nevada. Geochemical data support lithologic and faunal interpretations of relative basin positions of the Sunrise Formation stratigraphic sections, as well as basin development (including transgressive­-regressive sequences) during deposition of the Gabbs and Sunrise formations at New York Canyon (Gabbs Valley Range). All sections show characteristics of both oceanic and continental island arc sources. Rare positive Eu anomalies relative to chondrites suggest that the Gabbs Formation …

Distribution Of Heavy Metals And Trace Elements In Soils Of Southwest Oregon, Rafiqul Alam Khandoker

Dissertations and Theses

Soil samples from 118 sites on 71 geologic units in southwest Oregon were collected and analyzed to determine the background concentrations of metals in soils of the region. Sites were chosen in areas that were relatively undisturbed by human activities. The U.S. Environmental Protection Agency approved total-recoverable method was used to recover metals from samples for analysis. The twenty six metals analyzed were: Ag, AI, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Tl, V and Zn.

The Klamath Mountains followed by the Coast Range contain the …

Weak Bands Within Ice Stream B, West Antarctica, Christina L. Hulbe, I. M. Whillans

Geology Faculty Publications and Presentations

Kilometer-scale variations in ice velocity and surface topography are used to investigate the style of glacier deformation in the main body of Ice Stream B, West Antarctica. The pattern is very different from that reported for other glaciers. For the 250 km2 area studied on Ice Stream B, most of the observed deformation occurs within two narrow bands, in which there is large across-flow compression and slow lateral shearing. The bands underlie valleys in the ice-surface topography. Measured upward displacement of ice adjacent to the rapidly compressing bands appears to be linked to the creation of the ice stream's topography. …

Potential For Coastal Flooding Due To Coseismic Subsidence In The Central Cascadia Margin, Elson T. Barnett

Dissertations and Theses

Interpretations made from compilation of existing core and cutbank data for Oregon and Washington are used to evaluate the potential flooding impact from regional coseismic subsidence. Estimates of regional subsidence are based on tidal level indicators including plant macrofossils, peat development, and diatoms. A compilation of existing late Holocene stratigraphic records shows multiple burial events in all bays of Oregon, however some coastal sites in central Oregon show continuous submergence. Tests of tidal level indicators using modern Cascadia wetlands indicate that paleosubsidence can be estimated to 0.0 ± 0.5m, 1.0 ±0.5m, and 2 m ± 0.5m. An AMS date from …

Quantification Of Extraterrestrial Lava Flow Effusion Rates Through Laboratory Simulations, Tracy K.P. Gregg, Jonathan H. Fink

Geology Faculty Publications and Presentations

We have used carefully controlled laboratory simulations to develop a model which relates lava flow morphology to effusion rate and rheology. Through comparisons with measured and estimated eruption rates on Earth, this approach allows us to constrain eruptive styles and compositions of extraterrestrial lava flows. By applying this model to lava flows on the Moon, Mars and Venus, we have determined that all the common flow morphologies (domes, folds and levees) on these planets could have been produced by basalt-like or andesite-like lavas through either continuous or episodic emplacement. The presence of more evolved magma compositions on other planets is …

Correlation Of The Upper Ellensburg Formation With The Old Scab Mountain Eruptive Center, East-Central Cascade Range, Washington, Christopher Charles Humphrey

Dissertations and Theses

The Ellensburg Formation, preserved in the Nile basin 50 km northwest of Yakima, Washington, consists of a series of middle to late Miocene epiclastic and pyroclastic rock assemblages rich in porphyritic hornblende-biotite dacite. Geochemical, petrographic, and stratigraphic correlations indicate that Old Scab Mountain, a dacite porphyry intrusion, located at the western margin of the basin (lat. 46°53'30", long. 121°13'00"), is the probable source for much of the upper Ellensburg volcaniclastic material in the basin. The dacite intrusion exposed at Old Scab Mountain was emplaced at depths of 1 to 3 km and underlaid a now eroded volcanic edifice. This volcanic …

Beach Response To Subsidence Following A Cascadia Subduction Zone Earthquake Along The Washington-Oregon Coast, Debra Lee Doyle

Dissertations and Theses

Beach shoreline retreat induced by coseismic subsidence in the Cascadia subduction zone is an important post-earthquake hazard. Sand on a beach acts as a buffer to wave attack, protecting dunes, bluffs and terraces. The loss of sand from a beach could promote critical erosion of the shoreline. This study was initiated in order to estimate the potential amount of post subsidence shoreline retreat on a regional scale in the Central Cascadia Margin. The study area is a 331 km stretch of coastline from Copalis, Washington to Florence, Oregon. Several erosion models were evaluated, and the Bruun model was selected as …

Wear Due To The Physical And Petrographic Properties Of Rocks And Their Dynamic Interactions With Mining Equipment, Christian Poppeliers

Dissertations and Theses

Wear to mining equipment reduces operational efficiency. If wear rates can be predicted, appropriate matching of alloys to the mine' s geologic conditions can aid in improving the operational efficiency. This study addresses rock characteristics which lead to wear. Macroscopic rock tools which lead to wear include sharp edges and comers on rocks. During a rock/equipment interaction, these rock tools cause high point pressures on the surface of the equipment which leads to ductile cutting and gouging of the surface and subsequent removal of metal. Hard mineral grains, or grain tools, produce abrasion as the grains move across equipment surfaces. …

The Use Of Hydrochemistry To Identify Potential Processes Operating In The Saddle Mountains Basalt Aquifer And The Use Of The Nitrate-Nitrogen Isotope To Distinguish Between Potential Sources Of Nitrate To The Shallow Alluvial Aquifer In The Lower Umatilla Basin, Oregon, Margot Truini

Dissertations and Theses

Nitrate concentration in excess of national drinking-water standards (10 mg/l) are present in the shallow alluvial aquifer and Saddle Mountains Basalt (SMB) aquifer in the Lower Umatilla Basin, Oregon. To determine sources responsible for elevated nitrate concentrations in the SMB aquifer mass-balance and reaction-path models (NETPATH and PHREEQE) were used to understand observed geochemical trends. Nitrate-nitrogen isotopes were used to distinguish potential nitrate sources in the shallow alluvial aquifer. NETPATH-validated simple water/rock reactions in the SMB aquifers in Irrigon (dissolving glass, precipitating smectite, dissolving or precipitating calcite, and cation exchange) using constituents (calcium, magnesium, sodium and carbon). Diversity of composition …

An Ice-Shelf Model Test Based On The Ross Ice Shelf, D. R. Macayeal, V. Rommelaere, P. Huybrechts, Christina L. Hulbe, J. Determann, C. Ritz

Geology Faculty Publications and Presentations

A standard numerical experiment featuring the Ross Ice Shelf, Antarctica, is presented as a test package for the development and intercomparison of ice-shelf models. The emphasis of this package is solution of stress-equilibrium equations for an ice-shelf velocity consistent with present observations. As a demonstration, we compare five independently developed ice-shelf models based on finite-difference and finite-element methods. Our results suggest that there is little difference between finite-element and finite-difference methods in capturing the basic, large-scale flow features of the ice shelf. We additionally show that the fit between model and observed velocity depends strongly on the ice-shelf temperature field …

Geochemistry Of The Boring Lava Along The West Side Of The Tualatin Mountains And Of Sediments From Drill Holes In The Portland And Tualatin Basins, Portland, Oregon, Michelle Lynn Barnes

Dissertations and Theses

Instrumental Neutron Activation Analysis (INAA) was used to identify geochemical groups in Boring Lava along the west side of the Tualatin Mountains, and in sediments of the Portland and Tualatin basins. Samples of Boring Lava were obtained from TriMet drill core collected during planning of the tunnel alignment for the Westside Light Rail line. Additional samples of Boring Lava were collected from outcrops along the west side of the Tualatin Mountains. Samples of sediment from the Tualatin and Portland basins were obtained from drill core collected during an Oregon Department of Geology and Mineral Industries (DOGAMI) Earthquake Hazards Mapping project. …

The Distribution Of Naturally Occurring Soil Radionuclides And Radon Potential Of Northwest Oregon, Stuart Graham Ashbaugh

Dissertations and Theses

Radon, a naturally occurring radioactive gas produced as one of the decay products of soil/rock uranium and thorium, is considered to be a leading cause of pulmonary disease. Gamma spectrometry of 146 samples of soil were used to quantify radon source potential relative to lithology by measuring Bi²¹⁴ activity of the U²³⁸ decay series. Additional soil radio nuclide data (Th²³², Ac²²⁸, K40 and C¹³⁷ ) were used to help identify regional source provenance geochemistry and soil development. Ac²²⁸, Bi²¹⁴ and Th²³² activities in northwest Oregon soils range from five …

A Hydrologic Analysis Of Government Island, Oregon, Scott Gregory Bittinger

Dissertations and Theses

Government Island, located in the Columbia River approximately 16 km (10 mi) upstream of the confluence with the Willamette River, is a wetland mitigation site prompted by expansion of the southwest quadrant of Portland International Airport. The purpose of the study is to predict water levels in two enclosed lowland areas, Jewit Lake and Southeast Pond, based on levels of the Columbia River, precipitation, and evapotranspiration. Mitigation is intended to convert 1.13 km² (237 acres) of seasonally flooded wetland to 1.27 km² (267 acres) of semi-permanently flooded wetland and seasonally flooded wetland.

Flooding of the wetland is most …

Landslide Inventory And Susceptibility Mapping Of The Upper Canyon Creek Basin, Cascade Range, Skamania County, Washington, Lawrence P. Growney

Dissertations and Theses

Contact relations, and bedrock and overburden characteristics for approximately 8100 ha of the upper Canyon Creek basin, Skamania County, Washington, have been assessed in order to determine the causes and extent of failures and to assign slope failure susceptibilities to the area. The study area is located in the western Cascade Range on land administered by the Gifford Pinchot National Forest. Clear-cutting over the past 30 years has impacted between 50% to 80% of the study area.

The total surface area occupied by failure deposits (198.6 ha) is less than 2.5% of the study area. Failures occur by one of …

The Geology Of Parrett Mountain, Oregon, And Its Influences On The Local Groundwater Systems, Brett Todd Brodersen

Dissertations and Theses

A geologic study of the Parrett Mountain area, located twenty miles (32 kms) south-southwest of Portland, Oregon, was initiated by the Oregon Water Resources Department. The main goal was to create a stratigraphic and structural model of Parrett Mountain in order to better understand the local basalt aquifers present there.

Previous geologic studies of the area revealed the mountain to be composed of Columbia River basalt. Field mapping and hand lithologic and geochemical analyses allowed the basalt to be subdivided into eleven basalt flows. These flows are as follows: (from oldest to youngest) the Wapshilla Ridge (WpR), the Ortley-Grouse Creek …

Sediment Yield Analysis Of Reservoir #1, Bull Run Watershed, West Cascade Mountains, Oregon, Doann M. Hamilton

Dissertations and Theses

Bull Run Watershed was set aside in late the 1800s as the water supply source for the City of Portland. Other than two dams being constructed, Reservoir #1 (1929) and Reservoir #2 (1962), development of the land had been minimal as public access was restricted. In the early 1960s, land management changed with increased road building and timber removal raising concerns about increased sediment discharge into the reservoirs. The objective of this study is to evaluate how much and how fast the sediment has accumulated in Reservoir #1, and to determine if the rate of sediment accumulation has changed over …

Coastal Crossing Of The Elastic Strain Zero-Isobase, Cascadia Margin, South Central Oregon Coast, Gregory George Briggs

Dissertations and Theses

The analysis of marsh cores from the tidal zones of the Siuslaw, Umpqua, and Coos River systems on the south-central Oregon coast provides supporting evidence of coseismic subsidence resulting from megathrust earthquakes and reveals the landward extent of the zero-isobase. The analysis is based on lithostratigraphy, paleotidal indicators, microfossil paleotidal indicators, and radiocarbon age. Coseismic activity is further supported by the presence of anomalous thin sand layers present in certain cores. The analysis of diatom assemblages provides evidence of relative sea-level displacement on the order of 1 to 2 m. The historic quiescence of local synclinal structures in the Coos …