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Articles 23941 - 23970 of 29958
Full-Text Articles in Geology
Accommodation Space Controls On The Latest Pleistocene And Holocene (16–0 Ka) Sediment Size And Bypassing In The Lower Columbia River Valley: A Large Fluvial–Tidal System In Oregon And Washington, Usa, Curt D. Peterson
Geology Faculty Publications and Presentations
In this study, we establish the roles that increasing basin accommodation space have on sediment size and bypassing in the transgressive fill (16–0 ka) in the submerged Lower Columbia River Valley (LCRV). The antecedent forearc valley (225 km in length, 4–8 km in width, and 60–115 m in axial valley depth) is characterized by high sediment supply rates (10–15 million t y-1) but no delta at its mouth to the Pacific Ocean. Core sample sediment textures (N ¼ 1600) are analyzed from 3000 m of borehole sections in 58 representative boreholes to characterize the ancestral valley fill: 57% sand, 17% …
Integrated Geophysical Investigation Of The St. James Fault Complex: A Case Study, Robert W. Jacob, Jeremy B. Byler, Mary Beth Gray
Integrated Geophysical Investigation Of The St. James Fault Complex: A Case Study, Robert W. Jacob, Jeremy B. Byler, Mary Beth Gray
Faculty Journal Articles
We noninvasively detected the characteristics and location of a regional fault in an area of poor bedrock exposure complicated by karst weathering features in the subsurface. Because this regional fault is associated with sinkhole formation, its location is important for hazard avoidance. The bedrock lithologies on either side of the fault trace are similar; hence, we chose an approach that capitalized on the complementary strengths of very low frequency (VLF) electromagnetic, resistivity, and gravity methods. VLF proved most useful as a first-order reconnaissance tool, allowing us to define a narrow target area for further geophysical exploration. Fault-related epikarst was delineated …
Carbon And Oxygen Isotope Study Of Carbonates From Watling's Blue Hole And Blue Hole Five, San Salvador, Bahamas, Elaine D. Flynn
Carbon And Oxygen Isotope Study Of Carbonates From Watling's Blue Hole And Blue Hole Five, San Salvador, Bahamas, Elaine D. Flynn
Mahurin Honors College Capstone Experience/Thesis Projects
Carbonate platforms, such as the Bahamas, formed through deposition and sea level fluctuations. These platforms contain records of rapid interglacial climate change and are useful in studying the impacts of climate change on similar tropical carbonate environments. Blue holes are dissolution lakes that may be beneficial for understanding climate change and anthropogenic impact. A δ13C and δ18O study was conducted on lake sediment core samples from Watling’s Blue Hole and Blue Hole Five on San Salvador Island, Bahamas. These lakes are located in a failed housing development and Watling’s Blue Hole was once part of an …
A Bond Valence-Based Force Field: A Multi-Body Approach, Matthew Harris Davis
A Bond Valence-Based Force Field: A Multi-Body Approach, Matthew Harris Davis
Theses and Dissertations
The typical form for a molecular mechanics force field consists of a foundation of pair-wise terms to describe bonded and non-bonded atomic interactions, with multi-body correction terms to deal with the limitations of pair-wise terms. I present here the first attempts of a molecular mechanics model that is founded on multi-body terms, which are based on the Bond Valence Model (Brown, 2002) and recent developments in the Vectorial Bond Valence Model (Bickmore et al., 2013a; Harvey et al., 2006). I calibrated these models on pressure vs. energy curves for a set of SiO2 polymorphs. The average deviation for the best-fit …
The Size Range Of Bubbles That Produce Ash During Explosive Volcanic Eruptions, Kimberly Genareau, Gopal K. Mulukutla, Alexander A. Proussevitch, Adam J. Durant, William I. Rose, Dork L. Sahagian
The Size Range Of Bubbles That Produce Ash During Explosive Volcanic Eruptions, Kimberly Genareau, Gopal K. Mulukutla, Alexander A. Proussevitch, Adam J. Durant, William I. Rose, Dork L. Sahagian
Department of Geological and Mining Engineering and Sciences Publications
Volcanic eruptions can produce ash particles with a range of sizes and morphologies. Here we morphologically distinguish two textural types: Simple (generally smaller) ash particles, where the observable surface displays a single measureable bubble because there is at most one vesicle imprint preserved on each facet of the particle; and complex ash particles, which display multiple vesicle imprints on their surfaces for measurement and may contain complete, unfragmented vesicles in their interiors. Digital elevation models from stereo-scanning electron microscopic images of complex ash particles from the 14 October 1974 sub-Plinian eruption of Volcán Fuego, Guatemala and the 18 May 1980 …
Assessing The Reliability Of Stable Isotopes In Fossil Bone: A Unique Case Study Of Prehistoric Lung Pathology., Kathleen Bundy, Samuel D. Matson
Assessing The Reliability Of Stable Isotopes In Fossil Bone: A Unique Case Study Of Prehistoric Lung Pathology., Kathleen Bundy, Samuel D. Matson
Student Research Initiative
Mammals at Ashfall Fossil Beds State Historical Park (NE Nebraska) offer a unique opportunity to test for the preservation of primary isotopic signatures in fossilized materials. At this site, large herbivores such as rhinoceroses, horses and camels are buried in volcanic ash sourced from an eruption of the Bruneau-Jarbridge caldera (Idaho/Nevada) ca. 11.8 million years ago. Most fossils from Ashfall display pathologic bone symptomatic of a lung disease (hypertrophic osteopathy or HPOA) likely related to inhalation of volcanic ash. In this study, we compare the stable oxygen isotopic composition (δ18O) of pathologic bone with that of normal cortical …
The Influence Of Soil Organic Matter Stabilization Mechanisms On Carbon Mean Residence Time Within Various Ecosystems In The United States, Vicky Lynn Giese, Kate Heckman Phd
The Influence Of Soil Organic Matter Stabilization Mechanisms On Carbon Mean Residence Time Within Various Ecosystems In The United States, Vicky Lynn Giese, Kate Heckman Phd
STAR Program Research Presentations
Some terrestrial ecosystems and soils serve as carbon sinks, partially offsetting rising atmospheric CO2 levels. Physiochemical mechanisms of soil organic matter (SOM) stabilization affect how carbon stocks respond to global warming. In order to clarify the variance in SOM stabilization mechanisms across different soil types, SOM abundance, distribution and mean residence time (MRT) were compared for thirty-two soil samples from six ecosystems across the United States. Soils were previously described, collected and archived by the United States Geological Survey. Samples were processed by LLNL at the Center for Accelerator Mass Spectrometry (CAMS) using density fractionation to separate particulate organics …
Is Security Sustainable?, Jeremy W. Crampton
Is Security Sustainable?, Jeremy W. Crampton
Geography Faculty Publications
No abstract provided.
Lithic Analysis Of Coyote Canyon Mammoth Site Sediments, Kaitlin M. Hill, George V. Last
Lithic Analysis Of Coyote Canyon Mammoth Site Sediments, Kaitlin M. Hill, George V. Last
STAR Program Research Presentations
The landforms and geologic layers of Southeastern Washington record fascinating, unique geologic events, including repeated catastrophic flooding that occurred during the last Ice Age. These floods left behind many distinctive features, and a variety of fossils. After discovery of mammoth-sized bones in 1999, and confirmation that more bones were still in place in 2008, the Coyote Canyon Mammoth Site near Kennewick, Washington was secured for research, and formal excavation began in 2010.
Previous research suggests that the remains are buried in Ice Age flood deposits, which are overlain by eolian sediments, and those in turn overlain by slope wash. We …
Late Holocene Paleoenvironmental Reconstruction In Barbados, Gilman Reno Ouellette
Late Holocene Paleoenvironmental Reconstruction In Barbados, Gilman Reno Ouellette
Masters Theses & Specialist Projects
Barbados is the easternmost island in the Caribbean region, and is uniquely situated between the Atlantic Ocean and Caribbean Sea. Being an isolated island with a karstified aquifer providing the majority of the nation’s water resources, Barbados has found itself in water scarce situations in recent years. In order to better understand natural shifts in groundwater recharge (which is determined by shifts in precipitation), longer records of precipitation are needed than are available from modern measurements. This study presents a paleoclimate reconstruction for the late Holocene on Barbados using stable and radiogenic isotope ratios in speleothem lamina as proxies. In …
Analysis Of Kyrock For Leaching Of Impurities In Synthetic Rainwater, Santhosh Kumar Kasulavada
Analysis Of Kyrock For Leaching Of Impurities In Synthetic Rainwater, Santhosh Kumar Kasulavada
Masters Theses & Specialist Projects
Kyrock is a coarse grained sandstone with a complex mixture of organic and inorganic compounds. Mining of Kyrock is for use in road construction and roofing. Kyrock samples were analyzed using scanning electron microscopy to obtain elemental analysis. High levels of carbon indicate the presence of organic compounds. Analysis of an acid digestion of the samples using inductively coupled plasma spectroscopy showed inorganic compounds such as titanium oxide, vanadium oxide along with traces of arsenic. Elemental analysis of samples indicates a percent of carbon, and sulfur with no notable traces of nitrogen. Pyrolysis of the samples was done using gas …
Tectonosedimentologic Significance Of The Upper Cretaceous Foreland Basin Siliciclastics: Western Interior, Usa, Nazrul I. Khandaker
Tectonosedimentologic Significance Of The Upper Cretaceous Foreland Basin Siliciclastics: Western Interior, Usa, Nazrul I. Khandaker
Publications and Research
The Upper Cretaceous Frontier Formation exposed along the western margin of the western interior foreland basin is composed of clastic sediments that were deposited during the initial late Cretaceous transgressive-regressive phases of the Western Interior Seaway across Wyoming (Figure 1). Current study is aimed at providing attendees with the best practices associated with tectonic, lithofacies and sedimentologic interpretation of foreland basin sequences and emphasizing the need for utilizing field, structural, geochemical, and compositional data for reconstructing a viable scenario connected with foreland basin sedimentary packages. An attempt will be made to compare documented sedimentological findings with foreland basins located in …
Wettability Alteration Of Sandstone By Chemical Treatments, Yanling Wang, Li Ma, Baojun Bai, Guancheng Jiang, Jiafeng Jin, Zengbao Wang
Wettability Alteration Of Sandstone By Chemical Treatments, Yanling Wang, Li Ma, Baojun Bai, Guancheng Jiang, Jiafeng Jin, Zengbao Wang
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Liquid condensation in the reservoir near a wellbore may kill gas production in gas-condensate reservoirs when pressure drops lower than the dew point. It is clear from investigations reported in the literature that gas production could be improved by altering the rock wettability from liquid-wetness to gas-wetness. In this paper, three different fluorosurfactants FG1105, FC911, and FG40 were evaluated for altering the wettability of sandstone rocks from liquid-wetting to gas-wetting using contact angle measurement. The results showed that FG40 provided the best wettability alteration effect with a concentration of 0.3% and FC911 at the concentration of 0.3%.
Assessment And Conceptualization Of Groundwater Flow In The Edwards Aquifer Through The Knippa Gap In Uvalde County, Texas, Jennifer Raye Adkins
Assessment And Conceptualization Of Groundwater Flow In The Edwards Aquifer Through The Knippa Gap In Uvalde County, Texas, Jennifer Raye Adkins
Graduate Theses and Dissertations
The Edwards aquifer is one of the major regional karst aquifers in the United States, with an average withdrawal of 950 million liters per day (L/d). This investigation focuses on the connection between the Uvalde pool and the San Antonio pool of the Edwards aquifer, known as the Knippa Gap, west of the San Antonio metropolitan area in Uvalde County. This is a major zone of recharge to the Edwards aquifer and is approximately 6.4 km wide. The Knippa Gap is bounded by northeast trending faults of the Balcones Fault Zone (BFZ) on the north (specifically the Cooks and Trio …
Geometry And Evolution Of Fold Structures Within The High Folded Zone: Zagros Fold-Thrust Belt, Kurdistan Region, Iraq, Mjahid Zebari
Geometry And Evolution Of Fold Structures Within The High Folded Zone: Zagros Fold-Thrust Belt, Kurdistan Region, Iraq, Mjahid Zebari
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Understanding the deformation style within the Zagros Fold-Thrust Belt is crucial for understanding the convergence between the colliding Arabian and Eurasian plates and nature of structures that trap hydrocarbons within the belt. The Zagros Fold-Thrust Belt has propagated ~250 km southwest-ward in Northern Iraq. In this study, deformation style of a number of fault-related folds within a part of the belt has been considered. The research intends to understand the geometry and formation mechanisms of these folds, via constructing models for the deformation geometry of folds and associated thrusts at depth using field data and seismic lines and detecting their …
Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova
Boise State University Theses and Dissertations
The continuous Pennsylvanian shallow-marine, paralic, siliciclastic succession in the Donets Basin is pivotal for correlation of marine and continental strata in northern Pangaea with coeval shallow-marine mainly carbonate strata in the Moscow Basin, a historical type area of Moscovian Horizons. The details of the history of establishment, lithostratigraphy and current biostratigraphy of Podolskian and Myachkovian Horizons in the Moscow Basin that are not readily available in Western literature are reviewed.
A model of cyclic recurrence (~0.6 —1myr) of three main fusulinid assemblages in the Pennsylvanian siliciclastic-carbonate succession in the Donets Basin is proposed. A Hemifusulina-association (A) indicates the onset …
An Embodied Perspective Of Expertise In Solving The Problem Of Making A Geologic Map, Caitlin Norah Callahan
An Embodied Perspective Of Expertise In Solving The Problem Of Making A Geologic Map, Caitlin Norah Callahan
Dissertations
The task of constructing a geologic map is a cognitively and physically demanding field-based problem. The map produced is understood to be an individual’s two-dimensional interpretation or mental model of the three-dimensional underlying geology. A popular view within the geoscience community is that teaching students how to make a geologic map is valuable for preparing them to deal with disparate and incomplete data sets, for helping them develop problem-solving skills, and for acquiring expertise in geology. Few previous studies have focused specifically on expertise in geologic mapping. Drawing from literature related to expertise, to problem solving, and to mental models, …
Landslide Velocity, Thickness, And Rheology From Remote Sensing; La Clapiere Landslide, France, Adam M. Booth, Michael P. Lamb, Jean-Philippe Avouac, Christophe Delacourt
Landslide Velocity, Thickness, And Rheology From Remote Sensing; La Clapiere Landslide, France, Adam M. Booth, Michael P. Lamb, Jean-Philippe Avouac, Christophe Delacourt
Geology Faculty Publications and Presentations
Quantifying the velocity, volume, and rheology of deep, slow-moving landslides is essential for hazard prediction and understanding landscape evolution, but existing field-based methods are difficult or impossible to implement at remote sites. Here we present a novel and widely applicable method for constraining landslide 3-D deformation and thickness by inverting surface change data from repeat stereo imagery. Our analysis of La Clapiere, an approximately 1 km (super 2) bedrock landslide, reveals a concave-up failure surface with considerable roughness over length scales of tens of meters. Calibrating the thickness model with independent, local thickness measurements, we find a maximum thickness of …
Landslides Of Nebraska, Duane A. Eversoll
Landslides Of Nebraska, Duane A. Eversoll
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Insights Into The Timing, Origin, And Deformation Of The Highland Mountains Gneiss Dome In Southwestern Montana, Usa, Lane Markes Boyer
Insights Into The Timing, Origin, And Deformation Of The Highland Mountains Gneiss Dome In Southwestern Montana, Usa, Lane Markes Boyer
Graduate Theses and Dissertations
The Highland Mountains of southwestern Montana offer a unique view of the Archean igneous and metamorphic rocks within the Great Falls tectonic zone (GFTZ). A Paleoproterozoic structural gneiss dome has been interpreted in the southern extent of the Highland Mountains. The ∼ 130km2 of exhumed metamorphic rocks and gneiss dome exposed in the Highland Mountains are the primary focus of this research. The formation of the Highland Mountains gneiss dome is proposed to be directly related to a northwest-side down detachment (the Steels Pass shear zone) that formed during terrane collision along the GFTZ. The field investigation determined foliation …
A Geomechanical Study Of The Mississippian Boone Formation, Karen Nicole Mason Buckland
A Geomechanical Study Of The Mississippian Boone Formation, Karen Nicole Mason Buckland
Graduate Theses and Dissertations
The Boone Formation in northwest Arkansas is a chert-limestone sequence analogous to the subsurface Mississippi Lime reservoir in parts of Oklahoma and Kansas. It has low permeability and produces via horizontal drilling and hydraulic fracturing. The response to stimulation by fracturing is dependent on the quantity of chert in the area. Chert nodules and laterally extensive chert layers in the sequence are variable. Locally, cm- to dm-scale chert bedding is continuous and comprises up to 50% of the outcrop. Elsewhere, the chert is nodular and intermittent.
Samples collected from representative outcrops spanning the thickness and aerial extent of the formation …
Analysis Of Tripolitic Chert In The Boone Formation (Lower Mississippian, Osagean), Northwest Arkansas And Southwestern Missouri, Paul Marchand Minor
Analysis Of Tripolitic Chert In The Boone Formation (Lower Mississippian, Osagean), Northwest Arkansas And Southwestern Missouri, Paul Marchand Minor
Graduate Theses and Dissertations
The Boone Formation in northwest Arkansas and southwestern Missouri exposes a nearly complete sequence of Lower Mississippian chert-bearing carbonates deposited by a single 3rd order transgression and regression. An abundant amount of chert that has replaced limestone highlights the Boone, but little is understood about the timing and development of chert in Lower Mississippian carbonates. Interpretation of the diagenetic history of the chert, in particular tripolite, has significant implications beyond the outcrop. Determining the origin, timing, and extent of tripolitic chert in the Lower Mississippian System improves reservoir characterization in subsurface petroleum reservoirs in the mid-continent that are laterally equivalent …
Two Scenes From Utah's Stratigraphic Record: Neoproterozoic Snowball Earth, Before And After, Dawn Schmidli Hayes
Two Scenes From Utah's Stratigraphic Record: Neoproterozoic Snowball Earth, Before And After, Dawn Schmidli Hayes
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This research is focused on rock units deposited in northern Utah before and after global glacial events of unprecedented magnitude, commonly referred to as
“Snowball Earth” glaciations. The rock units deposited prior to the beginning of these glaciations (~770 to 740 million years ago) include the Uinta Mountain Group in Utah’s Uinta Mountains. Rock units deposited after the glaciations (either ~665 or ~635 million years ago) include parts of the Kelley Canyon Formation on Antelope Island in the Great Salt Lake. These rocks, deposited in shallow ocean environments, record the history of life and ocean chemistry just before and after …
Formation, Deformation, And Incision Of Colorado River Terraces Upstream Of Moab, Utah, Andrew P. Jochems
Formation, Deformation, And Incision Of Colorado River Terraces Upstream Of Moab, Utah, Andrew P. Jochems
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The history of rivers is laid down as sediment in all landscapes, typically as a function of climate, geologic structures, and/or changes in sea level. When a river abandons its floodplain, this sediment collectively constitutes a landform called a fluvial terrace. Terraces are used to unlock prior characteristics of a river flowing through a given area at both local and regional scales. Dating terrace sediment allows comparison to known changes in climate and geologic deformation, two significant controls on the hydraulics of rivers and the deposition of their sediment loads.
The importance of terraces lies in their utility as markers …
Population Dynamics Of Pseudo-Nitzschia Species (Bacillariophyceae) In The Near Shore Waters Of Dar Es Salaam, Tanzania, Charles Lugomela
Population Dynamics Of Pseudo-Nitzschia Species (Bacillariophyceae) In The Near Shore Waters Of Dar Es Salaam, Tanzania, Charles Lugomela
Tanzania Journal of Science
The genus Pseudo-nitzschia is a chain-forming diatom comprising about 30 species some of which are known to produce domoic acid (DA) that causes amnesic shellfish poisoning (ASP). The current study aimed at assessing the population dynamics of Pseudo-nitzschia in the near shore waters of Dar es Salaam. Samples were collected between August 2008 and July 2009 from two stations. The first station was located in the open waters off Mbudya Island and the second was located at a point in-between Kunduchi and Mbudya Island. Three Pseudo-nitzschia species, i.e., Pseudo-nitzschia pungens, Pseudo-nitzschia seriata and Pseudo-nitzschia cuspidata were encountered with Pseudo-nitzschia pungens …
Incision History Of Glenwood Canyon, Colorado, Usa, From The Uranium-Series Analyses Of Water-Table Speleothems, Victor J. Polyak, Harvey R. Duchene, Donald G. Davis, Arthur N. Palmer, Margaret V. Palmer, Yemane Asmerom
Incision History Of Glenwood Canyon, Colorado, Usa, From The Uranium-Series Analyses Of Water-Table Speleothems, Victor J. Polyak, Harvey R. Duchene, Donald G. Davis, Arthur N. Palmer, Margaret V. Palmer, Yemane Asmerom
International Journal of Speleology
Uranium-series analyses of water-table-type speleothems from Glenwood Cavern and “cavelets” near the town of Glenwood Springs, Colorado, USA, yield incision rates of the Colorado River in Glenwood Canyon for the last ~1.4 My. The incision rates, calculated from dating cave mammillary and cave folia calcite situated 65 and 90 m above the Colorado River, are 174 ± 30 m/My for the last 0.46 My and 144 ± 30 m/My for the last 0.62 My, respectively. These are consistent with incision rates determined from nearby volcanic deposits. In contrast, δ234U model ages (1.39 ± 0.25 My; 1.36 ± 0.25 …
Characterization Of The Shallow Subsurface Geohydrology Of The Ni-Les'tun Unit On The Bandon Marsh National Wildlife Refuge, Christopher Madison Beard
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 …
Grounding Zone Processes: Ice Mechanics And Margin Lakes, Kamb Ice Stream And Whillans Ice Stream, West Antarctica, Mason Joseph Fried
Grounding Zone Processes: Ice Mechanics And Margin Lakes, Kamb Ice Stream And Whillans Ice Stream, West Antarctica, Mason Joseph Fried
Dissertations and Theses
The lateral "corners" where Kamb and Whillans Ice Streams (KIS and WIS) discharge into the Ross Ice Shelf share common geometries and ice mechanical settings. At both corners of the now-stagnant KIS outlet, shear margins of apparently different ages confine regions with a relatively flat, smooth surface expression. These features are called the "Duckfoot" on the northern, right-lateral side and the "Goosefoot" on the other. It has been suggested, on evidence found in ice internal layers, that the flat ice terrains on KIS were afloat in the recent past, at a time when the ice stream grounding line was upstream …
Arsenic Mobility And Compositional Variability In High-Silica Ash Flow Tuffs, Courtney Beth Young Savoie
Arsenic Mobility And Compositional Variability In High-Silica Ash Flow Tuffs, Courtney Beth Young Savoie
Dissertations and Theses
Volcanic rocks typically have only low to moderate arsenic concentrations, none-the-less, elevated levels of arsenic in ground waters have been associated with pyroclastic and volcaniclastic rocks and sediments in many parts of the world. The potential for arsenic leaching from these deposits is particularly problematic as they often comprise important water-bearing units in volcanic terrains. However, the role that chemical and mineralogical variations play in controlling the occurrence and mobility of arsenic from pyroclastic rocks is largely unexplored.
This study uses chemical and X-ray diffraction data to characterize and classify 49 samples of ash-flow tuffs, and 11 samples of tuffaceous …
Hydrogeologic Characterization Of Dutch Canyon, Scappoose, Oregon, Derrick Lee Wagner
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 …