Digital Commons Network^™

Toward An Integrative Geological And Geophysical View Of Cascadia Subduction Zone Earthquakes, Maureen A.L. Walton, Lydia M. Staisch, Tina Dura, Jessie K. Pearl, Brian Sherrod, Joan Gomberg, Simon Engelhart, Ray E. Wells, Multiple Additional Authors

Geology Faculty Publications and Presentations

The Cascadia subduction zone (CSZ) is an exceptional geologic environment for recording evidence of land-level changes, tsunamis, and ground motion that reveals at least 19 great megathrust earthquakes over the past 10 kyr. Such earthquakes are among the most impactful natural hazards on Earth, transcend national boundaries, and can have global impact.Reducing the societal impacts of future events in the US Pacific Northwest and coastal British Columbia, Canada, requires improved scientific understanding of megathrust earthquake rupture, recurrence, and corresponding hazards. Despite substantial knowledge gained from decades of research, large uncertainties remain about the characteristics and frequencies of past CSZ earthquakes. …

Detecting Geomorphic Change And Stream Channel Evolution On The Sandy River, Oregon, Using Lidar Following Dam Removal In 2007, Lowell Henry Anthony

Dissertations and Theses

Following the removal of Marmot Dam on the Sandy River, Oregon, several Lidar flights were flown over the area of the former reservoir. The resultant sequential DEMs permitted calculation of reach-scale volumetric erosion and aggradation following dam removal. This allows for change detection across the entire affected reach of the former impoundment rather than just at several cross sections. In the first year there was a net loss of blank sediment in the dewatered reach. Subsequent flights show continued degradation of 145,649 m³ as well as aggradation of 6,232 m³. Sediment transport reached quasi-equilibrium in 2012 with …

Seismic Source Characterization Of Faults In The Portland And Tualatin Basins And A Paleoseismic Study Of The Gales Creek Fault, Or, Alison Elizabeth Horst

Dissertations and Theses

Portland, OR lies within the tectonically active forearc of the Cascadia subduction zone. Several, potentially hazardous, northwest striking faults in and around the Portland Basin are classified as Quaternary active by the USGS, but little is known about their Holocene activity. Geologic and geodetic studies in the Pacific Northwest (PNW) document ongoing clockwise rotation of the region since at least 16 Ma. Models for crustal deformation in the PNW suggest northwest trending faults accommodate dextral shear inferred from increasing clockwise rotation rates west of Portland. I compiled structural information to improve the seismic source characterization of these faults, and using …

Geochemistry And Petrography Of Igneous Components Of The Dalles Formation In The Dufur West Quadrangle, Oregon, Heather H. Herinckx

University Honors Theses

The Dalles Formation is a sequence of volcanic, volcaniclastic and sedimentary deposits of the late Miocene to Pliocene. The unit stretches along the eastern flanks of Mount Hood from Maupin, northward to the Columbia River, near The Dalles, Oregon (Figure 1). The Dalles Formation consists of lavas that are generally dacitic in composition and are composed of block-and-ash flows, debris-flows, and reworked fluvial sediments. Past workers have mapped the unit as the Dalles Formation "Undivided". The scope of this project has been to investigate the geochemical and petrographic characteristics and whether they may suggest distinct units. A section of the …

Geodesy- And Geology-Based Slip-Rate Models For The Western United States (Excluding California) National Seismic Hazard Maps, Mark D. Petersen, Yuehua Zeng, Kathleen M. Haller, Robert Mccaffrey, William C. Hammond, Peter Bird, Morgan Moschetti, Zheng-Kang Shen, Jayne Bormann, Wayne R. Thatcher

Geology Faculty Publications and Presentations

The 2014 National Seismic Hazard Maps for the conterminous United States incorporate additional uncertainty in fault slip-rate parameter that controls the earthquake-activity rates than was applied in previous versions of the hazard maps. This additional uncertainty is accounted for by new geodesy- and geology-based slip-rate models for the Western United States. Models that were considered include an updated geologic model based on expert opinion and four combined inversion models informed by both geologic and geodetic input. The two block models considered indicate significantly higher slip rates than the expert opinion and the two fault-based combined inversion models. For the hazard …

Chronology And Ecology Of Late Pleistocene Megafauna In The Northern Willamette Valley, Oregon, Daniel Mcgowan Gilmour

Dissertations and Theses

This study is an investigation of the timing of extinction of late Pleistocene, large bodied mammalian herbivores (megafauna) and of the environment in which they lived. The demise of the megafauna near the end of the Pleistocene remains unexplained. Owing to potential human involvement in the extinctions, archaeologists have been particularly concerned to understand the causes for faunal losses. Our current lack of understanding of the timing and the causes of the extinctions in North America may result from a deficiency in understanding the histories of each individual species of extinct animal on a local level. Detailed regional chronologies of …

Designing And Using Virtual Field Environments To Enhance And Extend Field Experience In Professional Development Programs In Geology For K-12 Teachers, Frank Douglas Granshaw

Dissertations and Theses

Virtual reality (VR) is increasingly used to acquaint geoscience novices with some of the observation, data gathering, and problem solving done in actual field situations by geoscientists. VR environments in a variety of forms are used to prepare students for doing geologic fieldwork, as well as to provide proxies for such experience when venturing into the field is not possible. However, despite increased use of VR for these purposes, there is little research on how students learn using these environments, how using them impacts student field experience, or what constitutes effective design in light of emerging theories of geocognition.

To …

Deforestation, Drought And Humans: New Discoveries Of The Late Quaternary Paleoenvironment Of Rapa Nui (Easter Island), Candace Lynn Gossen

Dissertations and Theses

The mystery of the trees of Rapa Nui (Easter Island) is a complex problem within a dynamic ecosystem. With new physical cores from the volcanic crater lake Rano Kao, this dissertation uncovers a detailed 15,000 year ecological history of Easter Island and its climatic variability. New radiocarbon dating methods establish a more precise chronology which shows that the island before human habitation was very different than what we know today. It had a simple but prolific ecology that transitioned into a barren grassland. What factors caused the transition are unclear but are likely to be human related. As the forests …

Radiative Transfer Theory Applied To Ocean Bottom Modeling, Jorge Quijano

Dissertations and Theses

Research on the propagation of acoustic waves in ocean bottom sediment is of interest for active sonar applications such as target detection and remote sensing. Currently, all seabed scattering models available in the literature are based on the full solution of the wave equation, which sometimes leads to mathematically intractable problems. In the electromagnetics community, an alternative formulation that overcomes some of this complexity is radiative transfer theory, which has established itself as an important technique for remote sensing. In this work, radiative transfer (RT) theory is proposed for the first time as a tool for the study of seabed …

Initiation Zone Characterization Of Debris Flows In November, 2006, Mount Hood, Oregon, Rachel Pirot

Dissertations and Theses

In November, 2006, a storm generated a minimum of 34 cm of precipitation in six days, triggering debris flows in many of the drainages on all sides of Mount Hood, Oregon. Of the eleven drainages surveyed, seven experienced debris flows; these include the White River, Salmon River, Clark Creek, Newton Creek, Eliot Creek, Ladd Creek and Sandy River basins. Flows in the White River, Eliot Creek, and Newton Creek, caused major damage to bridges and roadways. Initiation elevations averaged around 1,860 meters. Initiation zone material was predominantly sand (45-82%) with gravel (15-49%) and had few fines (3-5%). Four debris flows …

Magmatic Processes Operating During The Middle To Late Pliocene And Pleistocene Along The Transition Zone Near 43º North, Christy L. Lee

Dissertations and Theses

A geochemical and structural transition zone exists between the Cascades and Basin and Range provinces in Oregon. Geologic mapping in this area has allowed the definition of six volcanic rock sequences: 1) interfingered alkali-rich basaltic trachyandesite to trachydacite lava flows and low-alkali basaltic andesite lava flows, 2) HAOT lava flows, 3) basaltic andesite lava flows, 4) andesite lava flows and vent deposits with minor basaltic andesite lava flows, 5) HAB lava flows, and 6) interfingered basaltic andesite, andesite, and trachyandesite lava flows.

Geochemical models of sequence 1 alkali-rich rocks suggest the fractionation of the parent assemblage plag (An₅₅)+magn+ol±aug …

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, …

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 …

Objectivity In The Interpretation Of The Archaeology Of Ghana, E. Kofi Agorsah

Black Studies Faculty Publications and Presentations

One of the desires of the majority of archaeologists is to obtain from their analyses an objective knowledge of the societies they study. However, the mere desire to obtain objectivity does not ensure its attainment especially where biases cannot be controlled. Added to this difficulty of obtaining objectivity is that not only is the subject matter of archaeology vast and varied, but also archaeologists disagree on directions of study and interpretations, and in many cases very few scholars attempt to put themselves at a standpoint from which to measure the inadequacies and unevenness of their interpretations. Fundamental to interpretations in …

Slope Stability As Related To Geology At Rainier, Columbia County, Oregon, James Douglas Gless

Dissertations and Theses

Rainier, Oregon, has experienced problems in the development of residential and commercial sites, utilities, and transportation facilities as a result of slope instability. This study of slope stability at Rainier was conducted at the request of city officials.

Homestead Neighborhood And The Oregon Health Sciences University Background And Recommendations Report, Thomas Bizeau, Jim Crawford, Barton Delacy, Yousef Massoudifar, Tom Mcconnell, Foziah Rahman, Ezzat Rassoli, Barbara Sochacka

Master of Urban and Regional Planning Workshop Projects

The Homestead Neighborhood is located in southwest Portland. It was first studied as part of the Marquam Hill Plan in 1977. Since that time two major health providers, the Shriners and the Veterans Administration,have built new facilities on the hill. The Oregon Health Sciences University is now poised and ready for major expansion of its medical schools, hospital and research facilities. Meanwhile, area residents and property owners, have voiced concerns about increased traffic, and building density.

Oregon Health Sciences University (OHSU) contracted with the School of Urban and Public Affairs at Portland State University to draft a comprehensive neighborhood plan, …

Development And Application Of Some Quantitative Stratigraphic Techniques To The Coos Bay Coalfield, A Tertiary Fluvio-Deltaic Complex In Southwestern Oregon, Willard Sidney Titus Iii

Dissertations and Theses

A computer technique for interpreting geophysical logs of drill-holes in quantitative lithologic terms has been developed and tested on the deposits of the late Eocene Coaledo Formation, a well-studied fluvio-deltaic complex in southwestern Oregon. The technique involves the use of induced and natural gamma logs for separation of coal and claystone from coarse-grained detrital rocks and the use of the ratio of resistivity and natural gamma responses (defined here as the "grain size index") to divide the coarse elastic rocks into a series of textural classes corresponding to the Wentworth-Odden particle size scale.

Formation And Zonation Of Ferruginous Bauxite Deposits Of The Chapman Quadrangle, Oregon, Richard Charles Marty

Dissertations and Theses

Two major theories have been advanced to account for the scattered distribution of ferruginous bauxite deposits. Original workers proposed that ferruginous bauxite originally developed over all exposed Columbia River Basalt in western Oregon and was subsequently removed by erosion. Studies which followed have suggested that it may be locally favorable conditions, especially of drainage, which are responsible for deposit distribution. Field mapping in the Chapman Quadrangle shows a possible correlation between a series of sheared zones, which may have improved drainage, and the distribution of ferruginous bauxite deposits. Examination of the pisolitic zone ferruginous bauxite of the Chapman Quadrangle failed …

Portland State Perspective; Fall 1982, Portland State University

Portland State Perspective

A quarterly alumni newsletter. In this issue: School of Engineering and Applied Science; colored pencil art; PSU alumni in Hollywood; budget news.

The Stratigraphic Relationships Of The Columbia River Basalt Group In The Lower Columbia River Gorge Of Oregon And Washington, Terry Leo Tolan

Dissertations and Theses

The purpose of this study was to produce a detailed geologic map of the CRBG in the western portion of the Columbia River Gorge (fig. 1). The objectives were (1) to identify and delineate the extent of the Priest Rapids Member and Pomona Member intracanyon flows, and (2) to define the relationship of post-CRBG units to the CRBG intracanyon flows.

Stratigraphy, Structure, And Petrology Of The Snoqualmie Pass Area, Washington, Lawrence A. Chitwood

Dissertations and Theses

The Snoqualmie pass area lies about 50 mi (80 km) east of Seattle, Washington, along the crest of the Cascade Range. Five stratified units, forming a composite section over 22,000 ft (6700 m) thick, are recognized in the area. They were deformed and later intruded by granodiorite and quartz monzonite porphyry of the Snoqualmie batholith (middle Miocene). The oldest unit, the Denny Formation (Permian), 7000 ft (2100 m) thick, consists of interstratified basalt, andesite and dacite volcanic rocks and limestone and chert beds. This formation is unconformably overlain by a thick conformable sequence of early Tertiary strata which are subdivided, …

A Mineralogical And Geochemical Study Of The Ferruginous Bauxite Deposits In Columbia County, Oregon, And Wahkiakum County, Washington, Ronald Laverne Jackson

Dissertations and Theses

Wet chemical analysis and instrumental neutron activation analysis (INAA) were performed on a suite of samples from three residual ferruginous bauxite profiles in the study area for abundances of Al₂O₃,

SiO₂, Fe₂O₃, Ti O₂, Na, Sc, Hf, Cr, Co, La, Sm, Yb, Lu, and Th. In addition a mineralogical study accompanied this research, using petrographic, differential thermal, and x-ray diffraction techniques. In each profile, the relative mobility of these elements were calculated by empirical methods for comparison with the parent rock and mineral properties in the saprolite.

This …

Environmental Geology Of The Marquam Hill Area, Roger Alan Redfern

Dissertations and Theses

This work on Marquam Hill area in Portland, a relatively undeveloped urban hillside area, is a pilot study in which environmental factors are evaluated quantitatively in order to delineate limitations on development. The study was undertaken at the request of and in cooperation with the City of Portland Planning Commission and with the State of Oregon Department of Geology and Mineral Industries. Factors considered include various aspects of the land, vegetation and attitudes of inhabitants. Findings are not intended to satisfy need for individual site studies by qualified experts but should show where that expertise is needed.

Field data were …

Geophysical And Geological Analysis Of A Fault-Like Linearity In The Lower Clackamas River Area, Clackamas County, Oregon, Ronald Jay Schmela

Dissertations and Theses

A fault-like linearity along the lower Clackamas River is evaluated by analysis of physiographic and structural alignments, geological relationships, and by gravity and magnetic data. The study has resulted in the verification of a structural feature extending along the Clackamas River and the eastern front of the Portland Hills.

Physiographic alignments were examined in twelve 15 minute and two 7-1/2 minute quadrangle maps. A significant northeasterly morphologic trend, N. 20⁰ W. and N. 40° W., and other secondary trends, namely, the N-S, E-W, and N. 50-60° E., has developed in the Portland area. The consistent northwest trend is observed throughout …