Columbia River Basalt Group dikes cut the tonalite-granodiorite Wallowa Batholith in northeastern Oregon, providing a natural setting in which to examine partial melting. Many dikes have up to 5 m-wide zones of quenched partially melted wallrock at their margins. This paper examines the progressive partial melting reactions in biotite-and hornblende-bearing...
Oregon’s High Lava Plains Province (HLP) has strongly bimodal basalt and rhyolitic volcanism. The Province caps the northern margin of the Basin and Range Province and serves as a transitional region between westward extension of the Basin and Range Province and unextended crust to the north . The High Lava...
Eight Tertiary sedimentary and volcanic units crop out in the thesis area. From oldest to youngest they are the: Sager Creek formation (informal); Pittsburg Bluff Formation; Northrup Creek formation (informal); Smuggler Cove formation (informal); Wickiup Mountain and Cannon Beach members (both informal) of the Astoria Formation; the Grande Ronde Basalt,...
A study conducted along the Lincoln County, Oregon coast delineated the exact location of 153 landslides. The landslides were found through the interpretation of aerial photographs. Each landslide was verified in the field and its class (ancient, historic, recent), type (slump, debris slide or flow, planar slide),, and status (stable,...
During the period from July 1961 to September 1963, rocks were collected from 138 different locations on the continental shelf and slope off the central coast of Oregon by the Department of Oceanography, Oregon State University. The sample locations, types of samplers, and general lithologies for all of the samples...
During 1973 data was collected to analyze the seasonal variations of the tidal dynamics, water quality and sediments of the Alsea
Estuary. A summary of historical information with a list of all
known alterations to the estuary was made. A complete physical
description, including the geographical setting and mixing classification...
Page 112 seems to have been skipped by the publisher in page numbering. No page is missing. Discusses dredging methods and possible options for disposing of dredging spoils from Yaquina Bay. Includes maps of river segments showing possible disposal sites.
Grain-size distributions of gravels transported as bedload in Oak Creek, Oregon,
show systematic variations with changing flow discharges. At low discharges the gravel
distributions are nearly symmetrical and Gaussian. As discharges increase, the
distributions become more skewed and follow the ideal Rosin distribution. The patterns of
variations are established by...
"Nine (9) sediment samples and 1 QC duplicate were collected from Yaquina Bay and South Beach Marina (see Figures 1) on May 31, 2000. All samples were submitted for physical analyses, with 4 samples analyzed for metals (9 inorganic), total organic carbon (TOC), pesticides/polychlorinated biphenyls (PCBs), phenols, phthalates, miscellaneous extractables,polynuclear...
Elk River is a sixth order stream, draining a 200 square
kilometer basin in the Klainath Mountain province of
southwestern Oregon. Timber harvesting began in the basin
during the 1950's, with peak removal of wood occurring in the
mid to late 1960's. This activity lead to an increase in the...
This study addressed the effects of hilislope and fiuvial processes on spatial
patterns of stream bed particle size at the watershed, reach and within-reach scales.
The study was conducted in Lookout Creek watershed, a fifth-order, 64 km2 basin in
the Western Cascades mountains of Oregon. Stream bed particle size was...
Gathering empirical data on the factors and processes affecting bedload transport
in the field is difficult. This project conducted during the winter of 1996 field tested a new passive method of positively tracking individual particle movement. The project was conducted in Oak Creek, a gravel bedded stream, located in Corvallis,...
The results of light scattering measurements made with a Brice-Phoenix photometer and particle size distribution measurements made with a Model A Coulter Counter are presented. The data were collected on five cruises off the Oregon coast during the period June - October 1972. The cruises were a part of the...
In the Pacific Northwest, multiple studies have found negative effects of
timber harvest on stream amphibians, but the results have been highly variable and
region-specific. In this collection of studies, I examined the short term effect of timber
harvest using a field study, and used lab work to examine a...
Steens Mountain in SE Oregon is part of the northern Basin and Range Province,
and represents a horst tilted about 100 to the west that is bounded to the east by a high
angle, NNE trending normal fault. The minimum displacement is about 1200 m. Volcanic
rocks, exposed along the...
Forest harvesting practices can expose mineral soils, decrease infiltration capacities of soils, disturb the stream bank and channel, and increase erosion and fine sediment supply to stream channels. To reduce nonpoint source sediment pollution associated with forest management activities and to maintain the high water quality typically provided from forests,...
This dataset includes the datasets of suspended sediment concentration and environmental variables used to model stream metabolism, and the modeled stream metabolism results for two streams. For more information, see Cargill, SK (2019). The Influence of Lithology on Stream Metabolism in Mountain Systems. MS Thesis, Oregon State University.
An understanding of the factors that influence surface erosion from roads is necessary to prevent and mitigate sediment production from forest roads. This study investigated the impacts of log truck traffic and road hydrology on sediment yield from ten forest road segments in the foothills of the Cascade Mountains of...
During the Pleistocene, an andesitic volcano named Mount
Mazama grew to a probable elevation of 3000 meters in south-
central Oregon. Near the end of the Pleistocene, three diverse
magma types appeared in the eruptive products associated with Mount
Mazama: l)High-alumina basaltic andesite magma associated with an
early plateau and...
Wright's Point, a 250-foot-high, sinuous, flat-topped ridge, projects eastward into Harney Basin, Harney County, Oregon. This 6-mile-long feature ranges from 200 to 600 yards wide and merges with a broad mesa at its western end. The nearest topographic highs are Dog Mountain, 2 miles southwest, and foothills of the Blue...
Periodic violent eruptions from many different centers during Cenozoic time deposited vast quantities of pyroclastic material as ash-flow tuffs over most of Oregon, although the Coast Ranges and isolated patches elsewhere in the state appear to have been spared these recurring inundations. Eruptions occurred at different times throughout the Cenozoic,...
Published May 1998. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
New data are presented that provide evidence for the onset of extensional deformation in the Northwestern Basin and Range within 1 million years after the eruption of the Steens Basalt at 16.5 Ma. New geologic mapping (1:24,000), stratigraphic sections, and ⁴⁰Ar/³⁹Ar dating of the Crane Basin rocks provide a control...
Eleven sedimentary and volcanic rock units are mapped and described in the thesis area, and chronicle the dynamic geologic history of the Tillamook embayment from the Oligocene through the middle Mlocene. The
oldest unit is the Zemorrian to early Saucesian Smuggler Cove formation, a bathyal tuffaceous mudstone with some thin-...
Bar-pool morphology in rivers can provide vital habitat to aquatic species, notably salmonids, which require gravel riffles to bury eggs and pools for hydraulic and cold-water refuge. In some cases, the erosion and subsequent deposition of coarse sediment downstream of a dam removal can modify habitat by inundating bar-pool structure,...
Suspended sediment and in situ turbidity data from two western Oregon streams, Oak Creek and South Fork Hinkle Creek, were used to estimate annual sediment loads for the 2006 water year (October 1, 2005 to September 30, 2006). Water samples and in situ turbidity observations were taken following the Turbidity...
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Arne E. Skaugset III
Suspended sediment and in situ turbidity data from two western Oregon
In steep headwater basins of the Oregon Coast Range (OCR), debris flows episodically deliver material from low-order tributary basins to larger catchments. Much of this material is stored in valleys and gradually removed by fluvial processes. Quantifying the transfer of material from hillslopes to mainstem channels is essential in understanding...
With rising concentrations of CO₂ in the Earth's atmosphere causing
concern about climate change, many solutions are being presented to
decrease emissions. One of the proposed solutions is to sequester excess
CO₂ in geological formations such as basalt. The deep subsurface is known
to harbor much of the microbial biomass...
Tillamook Bay is the second largest estuary on the Oregon coast, and concerns have been raised whether human induced impacts have been responsible for the perceived increase in sedimentation rates during the past century. Major land-use practices within the five watersheds of the Bay include logging, forest fires, the construction...
The stacks off the southern Oregon coast have been studied very little because of difficulties of access (see, for example, Weissenborn and Snavely, 1968). Work described herein was helicopter-supported; skillful piloting by Earl Lady permitted landings on or close approaches to many stacks. To help delineate the structure, field work...
Various methods of presenting and mathematically describing particle
size distribution are explained and evaluated. The hyperbolic
distribution is found to be the most practical but the more complex
characteristic vector analysis is the most sensitive to changes in
the shape of the particle size distributions.
Particle size distribution, nutrient concentrations,...
The Central Oregon High Cascade Range is an anomalously mafic segment of the Cascade Arc due to ongoing intra-arc extension, which allows most magmas to traverse the crust without stalling and evolving to more evolved compositions. North Sister, a composite volcano in this arc segment, has produced a seemingly monotonous...
Elliptical borehole enlargements or "breakouts" caused by systematic spalling of a
borehole wall due to regional maximum horizontal stresses were identified in 18 wells
drilled in the Coast Range and Willamette Valley of western Oregon. The breakouts
generally indicate a NNW to NNE orientation of maximum horizontal compression
(oH[subscript max])...
The High Lava Plains province (HLP) of southeastern Oregon is a Miocene to Recent volcanic upland characterized by widespread basaltic volcanism and west-migrating rhyolitic volcanism. New ⁴⁰Ar/³⁹Ar ages for HLP rhyolites demonstrate that the trend of migrating rhyolitic volcanism is robust, reflecting westward migration at a rate of -35 km/m.y....
Various types of mass movement features are found in the drainage
basin of the East Fork Coquille River in the southern Oregon Coast
Range. The distribution and forms of mass movement features in the area
are related to geologic factors and the resultant topography.
The Jurassic Otter Point Formation, a...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals that the lower to middle Eocene forearc and subduction zone strata comprise four depositional sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
The Oregon coast between Yaquina Head and Government Point owes its scenic grandeur to a unique wedding of ancient and recent marine environments. Visitors to Beverly Beach State Park, located in the southern part of this coastal strip, have a rare opportunity to wander along a shoreline that some 15...
Coastal marsh vegetation is an important component in maintaining marsh stability that is threatened by changes in sedimentation, sea level rise, natural and anthropogenic disturbances, and competition from invasive species. Vegetation has been demonstrated to reduce wave energy, increase sedimentation, and decrease erosion in tidal environments under a range of...
As dams approach the end of their useful life, there is need to predict where and how accumulated sediment will move following their removal to estimate impacts on aquatic habitat and infrastructure. Flume studies suggest that sediment pulses disperse in place for most dams, but it is hypothesized that a...
Soil is a valuable medium when investigating the past-- from understanding rates of development, landform evolution, to the construction of various predictive models. Landforms and sediments provide insight into depositional environments and soil morphology indicates pedogenic change within those landforms. The rate at which pedogenesis occurs has been quantitatively measured...
In this report, a response is given to the charge of this study. Volume I: Summary Report includes a synopsis of the technical considerations followed by the main findings and recommendations. The full technical background for these summary statements is given in detail in Volume II: Technical Background Report, and...
Hopper dredge disposal of coarse grained sediment was
investigated between May and September, 1986, at a designated disposal
area, Site G, in Coos Bay, Oregon. The objectives of the study were
to: (a) identify and describe the benthic macrofaunal community
structure at Site G during May and September, 1986; (b)...
Unpaved roads are sources of chronic sediment in forested watersheds. Bare soil on roads is exposed to erosion from rainfall and runoff Published research on sediment production from forest roads focuses primarily on road characteristics. Since water drives the mechanics of sediment transport, hydrologic variables should correlate with sediment production....
River regulation imposes changes in the supply of sediment and the frequency of competent flows. As a result, impounded rivers often exhibit downstream changes in channel processes, particle size, and morphology. The magnitude of change in competent flow frequency and sediment load together can be used to predict the pattern...
Dam removal is increasingly viewed as a river restoration tool because dams affect so many aspects of river hydrology, geomorphology, and ecology; but removal also has impacts. When a dam is removed, sediment accumulated over a dam’s lifetime may be transported downstream; and the timing, fate and consequences of this...
The northern part of the Southeast Three Sisters quadrangle straddles
the crest of the central High Cascades of Oregon. The area is
covered by Pleistocene and Holocene volcanic and volcaniclastic rocks
that were extruded from a number of composite cones, shield volcanoes,
and cinder cones. The principal eruptive centers include...
The Murderers Creek Area, within the Aldrich Mountain province of
northeast Oregon, originated in an arc-trench gap during Permian-early
Triassic time. The area represents a small portion of a forearc
depositional basin and tectonic highland which borders the basin along
its seaward margin. The trench associated with an east dipping...
Nine west-northwest-trending faults on the continental margin of
Oregon and Washington, between 43° 05'N and 470 20'N latitude, have been
mapped using seismic reflection, sidescan sonar, submersibles, and swath
bathymetry. Five of these oblique faults are found on both the Juan de Fuca
and North American plates, and offset abyssal...
This report deals with a group of mineralized areas containing Tertiary veins of base metal and gold,· which occur at intervals throughout the Cascade Range in Oregon. Gold was discovered in this region in 1858, only a few years after its discovery in southwestern Oregon, and an output of nearly...
The purpose of this paper is to give a brief description of the volcano, and to report progress in the detailed mapping and petrologic study of its caldera. The increasing use of the Paulina and East Lake areas for recreation and nature study, and widespread interest in the geology aroused...
Our studies and those of our colleagues in Idaho indicate that the western Snake River Basin is a major geothermal province, similar in some ways to the Imperial Valley Geothermal Province. Deep drilling should encounter high temperature fluids in permeable rocks below 2 km and at shallower depths where permeability...
Stein's Pillar area, central Oregon / Aaron C. Waters -- Seismic reflection studies of buried channels off the Columbia River / Joseph W. Berg, Jr., John M. King, and Paul R. Carlson.
"It is the purpose of this paper, through a brief review of the history of Astoria, to construct a framework of the physical history of the city, to place each published geologist in his correct historical setting within the city, and to reestablish his locales so as to be presently...
Salmonid populations in the Pacific Northwest are at historic lows and many
populations continue to decline. Previous studies have linked salmonid declines to land
use through degradation of in-stream physical habitat, but few of these studies have taken
geology into consideration. This study relates habitat parameters known to be important...
Management of small dams may have profound implications for the health and integrity of small rivers and freshwater diversity. Global indicators suggest future growth in the small hydropower sector, particularly in developing countries. As a renewable energy source, it is often presumed that small hydropower entails fewer and less severe...
Sediment yield increases following timber harvest and road construction
were predicted for four Pacific Northwest experimental
watersheds. Sediment yields were predicted using a handbook developed
by the U.S. Forest Service entitled, "An Approach to Water Resources
Evaluation of Non-Point Silvicultural Sources" (WRENS). Predicted
sediment yield increases varied from 40 to...
The U.S. Geological Survey (USGS) has worked cooperative with the Unified Sewerage Agency of Washington County (USA) since 1990 to assess water quality in the Tualatin River Basin. The objectives of this study were to: assess the occurrence and magnitude of trace element and selected organic contaminants in streams of...
This report presents results of an investigation of water and streambed-sediment quality in selected tributaries of the South Umpqua River. Concentrations of inorganic constituents in water (major and minor ions, nutrients, and trace elements) and streambed sediment (primarily trace elements), along with standard field parameters, are tabulated for samples collected...
Magnetic and gravity modelling was completed along two E-W transects offshore central Oregon. These models indicate that the backstop-forming western edge of the Siletz terrane has a seaward dip of approximately 40° to 49° at 44°48'N, shallowing to ~28° at 44°1 1 'N. This is a well-determined result, given available...
Published November 1973. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the Sea Grant Catalog: http://seagrant.oregonstate.edu/publications