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Articles 511 - 540 of 670

Full-Text Articles in Earth Sciences

Review Of The United States Environmental Protection Agency Superfund Technical Assistance Grant Program, Robert Leslie Annear, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt Jun 1997

Review Of The United States Environmental Protection Agency Superfund Technical Assistance Grant Program, Robert Leslie Annear, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt

Civil and Environmental Engineering Faculty Publications and Presentations

The EPA Technical Assistance Grant Program has been around for several years, but there are not many examples of its use in the Pacific Northwest from which citizens can learn from when considering applying for a Technical Assistance Grant. The EPA program is designed to provide citizens with technical assistance in understanding the issues related to a Superfund site (or proposed Superfund site) in their community. This report provides an overview of the Technical Assistance Grant Program with information on applying for the grant, selecting a Technical Advisor and managing the grant. Additionally two case studies are reviewed in order …


Settlements Due To Arid Collapsible Soils, Heather L. Devine May 1997

Settlements Due To Arid Collapsible Soils, Heather L. Devine

Dissertations and Theses

The arid alluvial deposits common to the western United States frequently undergo moderate to severe collapse when wetted that can threaten or destroy the stability of structures that are founded on such soils. Additionally, in some areas collapse has been known to occur due to overburden stresses alone. As development expands in these areas a method to estimate the degree of this collapse is essential.

Current settlement methods are reviewed and evaluated as they apply to collapsible soils, providing a basis for the development of a proposed settlement method for determining collapse. To aid in the determining the basis for …


Geochemistry, Stratigraphy And Provenance Of The Portland Hills Silt In The Tualatin Mountains, Portland, Oregon, John L. Lawes Iii May 1997

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 May 1997

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 May 1997

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 May 1997

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 Apr 1997

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 …


The Columbia Slough, Scott A. Wells Mar 1997

The Columbia Slough, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

This report was written in an attempt to provide the public and Bureau of Environmental Services Staff with a summary of work accomplished on the Columbia Slough system by Portland State University and other consultants working on the Slough over the last 6 years. An attempt was made to create an easy-to-read report with important overviews of the "big picture", glossary of definitions, index, and further details to assist in technology transfer.


Potential For Coastal Flooding Due To Coseismic Subsidence In The Central Cascadia Margin, Elson T. Barnett Jan 1997

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 …


A Strategy For Monitoring Glaciers, Andrew G. Fountain, Robert M. Krimmel, Dennis C. Trabant Jan 1997

A Strategy For Monitoring Glaciers, Andrew G. Fountain, Robert M. Krimmel, Dennis C. Trabant

Geography Faculty Publications and Presentations

Glaciers are important features in the hydrologic cycle and affect the volume, variability, and water quality of runoff. Assessing and predicting the effect of glaciers on water resources require a monitoring program to provide basic data for this understanding. The monitoring program of the U.S. Geological Survey employs a nested approach whereby an intensively studied glacier is surrounded by less intensively studied glaciers and those monitored solely by remote sensing. Ideally, each glacierized region of the United States would have such a network of glaciers. The intensively studied glacier provides a detailed understanding of the physical processes and their temporal …


Weak Bands Within Ice Stream B, West Antarctica, Christina L. Hulbe, I. M. Whillans Jan 1997

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. …


Impact Of Groundwater Contamination In East Multnomah County On The Interlachen Community, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt, Robert Leslie Annear, Karann Brandt Oct 1996

Impact Of Groundwater Contamination In East Multnomah County On The Interlachen Community, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt, Robert Leslie Annear, Karann Brandt

Civil and Environmental Engineering Faculty Publications and Presentations

The Friends of Blue and Fairview Lake through the Environmental Protection Agency (EPA) Technical Assistance Grant (TAG) program contracted with Portland State University faculty and staff to provide an independent review of the groundwater contamination problem at the Boeing-Cascade site in East Multnomah County. An independent consultant, Karann Brandt, of PRC Environmental Management, Inc., was also assisting the panel with the review.

The region of groundwater contamination is a 2.5 square mile region bounded by NE Halsey Blvd. to the Columbia River and NE 178th to NE 223rd (see Figure 1). The groundwater contamination is primarily of volatile organic compounds …


Quantification Of Extraterrestrial Lava Flow Effusion Rates Through Laboratory Simulations, Tracy K.P. Gregg, Jonathan H. Fink Jul 1996

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 Jul 1996

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 Jun 1996

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 May 1996

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. …


Groundwater Recharge Of The Middle Deschutes Basin, Oregon, Thomas Gene Boyd Mar 1996

Groundwater Recharge Of The Middle Deschutes Basin, Oregon, Thomas Gene Boyd

Dissertations and Theses

All surface water in the Middle Deschutes River basin of Oregon has already been allocated. Growth in the basin has put pressure on the Oregon Water Resources Department (OWRD) to grant an increasing number of groundwater permits. The OWRD is concerned that the allocation of too much groundwater will cause adverse effects on other groundwater users and surface water supplies and ultimately lead to groundwater depletion. For this reason, the U.S. Geological Survey is presently undertaking the first in-depth study of the groundwater resources of the basin.

As part of this USGS study, I estimated recharge rates and their distribution …


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 Feb 1996

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 Jan 1996

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 Oct 1995

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 Jun 1995

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 May 1995

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 …


Indicators Of Nutrient Limited Plankton Growth In Lakes Near Mount Saint Helens, Washington, Kurt Davis Carpenter Dec 1994

Indicators Of Nutrient Limited Plankton Growth In Lakes Near Mount Saint Helens, Washington, Kurt Davis Carpenter

Dissertations and Theses

Several lakes located in the blast zone of the 1980 eruption of Mount St. Helens were studied to determine if the plankton in the lakes were limited in their growth by nitrogen or phosphorus availability. Long term nutrient enrichment experiments were performed on lake water from five lakes and measures of chlorophyll-a, carbon fixation, and nutrient uptake were used to evaluate the extent of limitation. Nutrient concentrations, ratios, and uptake from 14 lakes provided additional evidence for limitation by nitrogen and/or phosphorus. The physical, chemical, and biological characteristics of the lakes were also examined to monitor the return of these …


Landslide Inventory And Susceptibility Mapping Of The Upper Canyon Creek Basin, Cascade Range, Skamania County, Washington, Lawrence P. Growney Oct 1994

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 Sep 1994

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 Sep 1994

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 Aug 1994

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 …


Magmatic Evolution And Eruptive History Of The Granitic Bumping Lake Pluton, Washington: Source Of The Bumping River And Cash Prairie Tuffs, John Frederick King May 1994

Magmatic Evolution And Eruptive History Of The Granitic Bumping Lake Pluton, Washington: Source Of The Bumping River And Cash Prairie Tuffs, John Frederick King

Dissertations and Theses

The 25 Ma Bumping Lake pluton ranges in composition from quartz diorite to granite with the granitic facies comprising approximately 90% of the pluton's surface area. The granite may be classified as calcalkaline, peraluminous and I-type with some Stype characteristics. A late-stage, mafic-poor facies fills cooling related extensional fractures. The pluton was passively emplaced into the Ohanapecosh Formation at a shallow level in the crust. Contact relationships vary from sharp where the contact is vertical to gradational at the roof of the pluton. Where gradational, stoped xenoliths from the roof of the pluton increase in size, angularity and retain more …


The Holocene Sedimentary Framework Of The Lower Columbia River Basin, Edward Breed Gates Apr 1994

The Holocene Sedimentary Framework Of The Lower Columbia River Basin, Edward Breed Gates

Dissertations and Theses

The Columbia River is the largest fluvially dominated estuary in the Pacific Northwest, yet the Holocene transgressive fill of this system has not previously been studied. Nearly 1500 industry borehole and water well records in the lower Columbia River basin (LCRB) were analyzed. These records document the sedimentary infilling of the lower 120 miles of the drowned river valley that occurred during the Holocene marine transgression (10-0 ka). Of particular importance is a key stratigraphic marker horizon of volcanic tephra that has been identified throughout the LCRB. INAA was used to determine the geochemical composition of the target tephra layer. …


Source Rock Geochemistry Of The Southern Tyee Basin, Southwest Oregon, David E. Long Jan 1994

Source Rock Geochemistry Of The Southern Tyee Basin, Southwest Oregon, David E. Long

Dissertations and Theses

This study examined source rock geochemistry of the southern Tyee Basin. Total organic carbon, rock-eval pyrolysis, vitrinite reflectance, thermal alteration index and visual assessments were performed on splits from cutting samples from five wells and on outcrop samples from four measured sections. Organic matter was found to be dispersed, averaging about 0.5 weight percent. The organic matter is primarily terrestrial in origin, or type I l l , with low potential for gas production and no oil potential. Three coal samples are clearly the richest sources of organic matter examined in this study.