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Full-Text Articles in Geology

Is Sensitivity To Anticoagulant Rodenticides Affected By Repeated Exposure In Hawks?, Barnett A. Rattner, Rebecca S. Lazarus, Thomas G. Bean, Katherine E. Horak,, Steven F. Volker, Julia Lankton Jan 2018

Is Sensitivity To Anticoagulant Rodenticides Affected By Repeated Exposure In Hawks?, Barnett A. Rattner, Rebecca S. Lazarus, Thomas G. Bean, Katherine E. Horak,, Steven F. Volker, Julia Lankton

United States Geological Survey: Staff Publications

A seminal question in wildlife toxicology is whether exposure to an environmental contaminant, in particular a secondgeneration anticoagulant rodenticide, can evoke subtle long lasting effects on body condition, physiological function and survival. Many reports indicate that non-target predators often carry residues of several rodenticides, which is indicative of multiple exposures. An often-cited study in laboratory rats demonstrated that exposure to the second-generation anticoagulant rodenticide brodifacoum prolongs blood clotting time for a few days, but weeks later when rats were re-exposed to the first-generation anticoagulant rodenticide warfarin, coagulopathy was more pronounced in brodifacoum-treated rats than naïve rats exposed to warfarin. To …


Paleogene-Early Neogene Palynomorphs From The Eastern Equatorial Atlantic And Southeastern Florida, Usa: Biostratigraphy And Paleoenvironmental Implications, Walaa K. Awad Jan 2018

Paleogene-Early Neogene Palynomorphs From The Eastern Equatorial Atlantic And Southeastern Florida, Usa: Biostratigraphy And Paleoenvironmental Implications, Walaa K. Awad

Doctoral Dissertations

"The transition from greenhouse conditions (Paleocene-Eocene Thermal Maximum, PETM) to icehouse conditions (Early Oligocene) is not well documented in tropical-subtropical regions. One hundred and five samples from Ocean Drilling Program (ODP) Site 959 (Hole 959A and Hole 959D) in the Cote d'Ivoire-Ghana Transform Margin, Alo-1 Well in the northern Niger Delta (Anambra) Basin, Nigeria, and W-17001 in southeastern Florida were studied for their palynological contents. Dinoflagellate cysts were mainly utilized for age refinement and to detect subtle changes in paleoenvironment and paleoclimate during the Paleocene-Early Eocene (ODP Hole 959D and Alo-1 Well) and Late Eocene-Early Miocene (ODP Hole 959A and …


Lithospheric Layering And Thickness Beneath The Contiguous United States, Lin Liu Jan 2018

Lithospheric Layering And Thickness Beneath The Contiguous United States, Lin Liu

Doctoral Dissertations

"The Upper Mississippi Embayment (UME), where the seismically active New Madrid Seismic Zone resides, experienced two phases of subsidence commencing in the Late Precambrian and Cretaceous, respectively. To provide new constraints on models proposed for the mechanisms responsible for the subsidence, we computed and stacked P-to-S receiver functions recorded by 49 USArray and other seismic stations located in the UME and the adjacent Ozark Uplift and modeled Bouguer gravity anomaly data. The inferred thickness, density, and Vp/Vs of the upper and lower crustal layers suggest that the UME is characterized by a mafic and high-density upper crustal layer of ∼30 …


Conical Folds -- An Artifact Of Using Simple Geometric Shapes To Describe A Complex Geologic Structure, Avery Joseph Welker Jan 2018

Conical Folds -- An Artifact Of Using Simple Geometric Shapes To Describe A Complex Geologic Structure, Avery Joseph Welker

Masters Theses

"Accurate representation of the 3D shapes of natural folds is essential to characterization of the dynamic models for fold formation. Geometrical analysis of folds commonly relies upon analyzing patterns defined by the variation in the orientation of poles to planar surfaces deformed by a shortening event when plotted using graphical calculators (e.g., stereogram, polar tangent diagrams) to interpret the shape of folds. Stereograms for which orientation data define small circles are classified as non-cylindrical regular folds and are interpreted as "conical folds," where the shape of the fold is represented by a cone that terminates at a point. Utilizing similar …


A New Approach To Probabilistic Lava Flow Hazard Assessments, Applied To The Idaho National Laboratory, Eastern Snake River Plain, Idaho, Usa, Elisabeth Gallant, Jacob Richardson, Charles Connor, Paul Wetmore, Laura Connor Jan 2018

A New Approach To Probabilistic Lava Flow Hazard Assessments, Applied To The Idaho National Laboratory, Eastern Snake River Plain, Idaho, Usa, Elisabeth Gallant, Jacob Richardson, Charles Connor, Paul Wetmore, Laura Connor

School of Geosciences Faculty and Staff Publications

We present a new probabilistic lava flow hazard assessment for the U.S. Department of Energy’s Idaho National Laboratory (INL) nuclear facility that (1) explores the way eruptions are defined and modeled, (2) stochastically samples lava flow parameters from observed values for use in MOLASSES, a lava flow simulator, (3) calculates the likelihood of a new vent opening within the boundaries of INL, (4) determines probabilities of lava flow inundation for INL through Monte Carlo simulation, and (5) couples inundation probabilities with recurrence rates to determine the annual likelihood of lava flow inundation for INL. Results show a 30% probability of …


Grenvillian Tectonomagmatic Evolution Of Southwestern Laurentia; Virtual Tour Of Multidimensional Orders Of Scale; Two Methods To Describe The Vastness Of Time; Math Concepts Utilizing Google Earth; Systematic Approach To Motion Analyses; Mathematics And Earth Science-Based Knowledge And Learning, Anthony M. Alvarez Jan 2018

Grenvillian Tectonomagmatic Evolution Of Southwestern Laurentia; Virtual Tour Of Multidimensional Orders Of Scale; Two Methods To Describe The Vastness Of Time; Math Concepts Utilizing Google Earth; Systematic Approach To Motion Analyses; Mathematics And Earth Science-Based Knowledge And Learning, Anthony M. Alvarez

Open Access Theses & Dissertations

This Dissertation is the product of several individual multi-disciplinary investigations that cover a variety of topics in mathematics, physics, geology, and geoscience education. The first chapter formulates a better understanding of the timings, magma source, and relationships between dikes and associated magmatic bodies of the Red Bluff Granitic Complex to provide a clearer picture of the evolution of post-Grenville magmatism and tectonism of southwestern USA. The second chapter provides an improved method for representing spatial information in the form of a multidimensional virtual tour where the background map is used as a central object. The third chapter describes two methods …


Evaluating Fold And Thrust Systems Within An Inverted Basin: Indio Mounntains, West Texas, Myra Guerrero Jan 2018

Evaluating Fold And Thrust Systems Within An Inverted Basin: Indio Mounntains, West Texas, Myra Guerrero

Open Access Theses & Dissertations

Fold and thrust belts often are complicated by out of sequence thrust faulting and inverted basins display these structures particularly often due to reactivation of original normal faults as well as complex topographic evolution. The Indio Mountains lie along the northern margin of the Chihuahua trough which formed as a mid-Cretaceous extensional basin and was subsequently shortened during the Laramide orogeny, making the Indio Mountains an exceptional site for studies of structures produced by large scale basin inversion. This study focuses on the subsurface structures in a complexly imbricated thrust window developed along the paleo rift basin margin.

This study …


Geometry, Timing, And Kinematics Of Neogene Extensional And Transtensional Structures Of Southern Death Valley: Implications For Regional Reconstructions And A Corrective Method For Rigid Body Rotations, Zachariah Fleming Jan 2018

Geometry, Timing, And Kinematics Of Neogene Extensional And Transtensional Structures Of Southern Death Valley: Implications For Regional Reconstructions And A Corrective Method For Rigid Body Rotations, Zachariah Fleming

Open Access Theses & Dissertations

Chapter 1:Advancements in computing capabilities over the last decade have allowed for the routine creation of Structure from Motion-Multiview Stereo (SfM-MVS) terrain models that can serve as base for high resolution geologic mapping. Outcrops models developed from these systems are high-resolution, photo-realistic 3D base providing unprecedented capability for geometric analysis. Yet, before this technology becomes a mainstay of field geology, the potential errors associated with it must be well understood. Here, we compare orientation measurements from multi-point analyses on the SfM-MVS point clouds to those taken in the field with the objective of resolving the geometry of complex folds within …


Characterization And Geochemistry Of Carbonate Caprock Associated With The Gypsum Valley Salt Wall, Paradox Basin, Colorado: Implications For Understanding Lateral Caprock Emplacement, Piper Lee Poe Jan 2018

Characterization And Geochemistry Of Carbonate Caprock Associated With The Gypsum Valley Salt Wall, Paradox Basin, Colorado: Implications For Understanding Lateral Caprock Emplacement, Piper Lee Poe

Open Access Theses & Dissertations

On the northeastern side of Gypsum Valley salt wall in the Paradox Basin of Colorado, discontinuous exposures of layered gypsum and carbonate rocks were previously mapped as the contact between diapiric Paradox Formation and marine limestone of the Pennsylvanian Honaker Trail Formation. Utilizing new and existing mapping, petrographic and isotopic geochemical analyses, this study reinterprets this zone to represent lateral gypsum and carbonate caprock that formed in the Triassic during passive rise of the Gypsum Valley salt wall. Gypsum Valley lateral carbonate caprock can be distinguished from Pennsylvanian and Permian depositional carbonate strata exposed elsewhere on the salt wall by …


Combining Hydraulic Head Analysis With Airborne Electromagnetics To Detect And Map Impermeable Aquifer Boundaries, Jesse T. Korus Jan 2018

Combining Hydraulic Head Analysis With Airborne Electromagnetics To Detect And Map Impermeable Aquifer Boundaries, Jesse T. Korus

Conservation and Survey Division: Faculty and Staff Publications

Impermeable aquifer boundaries affect the flow of groundwater, transport of contaminants, and the drawdown of water levels in response to pumping. Hydraulic methods can detect the presence of such boundaries, but these methods are not suited for mapping complex, 3D geological bodies. Airborne electromagnetic (AEM) methods produce 3D geophysical images of the subsurface at depths relevant to most groundwater investigations. Interpreting a geophysical model requires supporting information, and hydraulic heads offer the most direct means of assessing the hydrostratigraphic function of interpreted geological units. This paper presents three examples of combined hydraulic and AEM analysis of impermeable boundaries in glacial …


The Groundwater Atlas Of Red Willow County, Nebraska, Dana Divine, Duane Eversoll, Leslie M. Howard Jan 2018

The Groundwater Atlas Of Red Willow County, Nebraska, Dana Divine, Duane Eversoll, Leslie M. Howard

Conservation and Survey Division: Faculty and Staff Publications

The purpose of this groundwater atlas is to synthesize a wealth of hydrogeologic data for Red Willow County that has not been published in readily accessible formats previously. Many of the maps presented here are based on geologic information from registered wells and test holes that is publically available on-line, which becomes more valuable when compiled, analyzed, and discussed as a whole.

In Red Willow County, the aquifers are alluvial sand and gravel in the river and stream valleys and the High Plains aquifer beneath the uplands. The High Plains aquifer in Red Willow County consists primarily of the Ogallala …


Exploring The Relationship Between The Nemaha Uplift And The Mid-Continent Rift Using 3d Mapping Visual Analysis, Faris Abanumay Jan 2018

Exploring The Relationship Between The Nemaha Uplift And The Mid-Continent Rift Using 3d Mapping Visual Analysis, Faris Abanumay

Master's Theses or Doctor of Nursing Practice

The present study presents and explains the relationship between Nemaha uplift and Mid-continent rift (MCR), where the understanding of the faulting systems around the study region were extremely important with regard to finding the relationship. The Nemaha is located in Kansas State in the Central United States with a total area of about 719 square miles. It was formed around the pre- Mississippian era. The compression and rifting processes that led to formation of faults, volcanoes, ridges and oceanic plates controls the faulting in the Nemaha region. The MCR system is a major tectonic feature in North America that is …


Quantifying The Offset Of Greenhouse Gas Emissions At The University Of North Alabama, Paul Dunn Graham Jan 2018

Quantifying The Offset Of Greenhouse Gas Emissions At The University Of North Alabama, Paul Dunn Graham

Theses

No abstract provided.


Hillslope Coupled Stream Morphology, Flow Conditions, And Their Effects On Detrital Sedimentology In Garnet Canyon, Teton Range, Wyoming, Lisa M. Tranel Jan 2018

Hillslope Coupled Stream Morphology, Flow Conditions, And Their Effects On Detrital Sedimentology In Garnet Canyon, Teton Range, Wyoming, Lisa M. Tranel

Faculty Publications - Geography, Geology, and the Environment

Characterizing stream erosion in any steep mountain landscape is arduous, but the challenge level increases when the stream flows through a glaciated catchment frequently modified by hillslope debris. Glacial landforms and stochastic mass wasting in alpine systems may interfere with sediment delivery to downstream sites where detrital sediments are often collected to represent upstream bedrock sources. To use detrital sediments as indicators of erosion, we need to understand potential sediment accumulation in flat glaciated reaches or behind rockfall barriers. This study investigates the stream channel in Garnet Canyon, a glaciated catchment located in the central Teton Range, to describe hillslope …


New Geologic Mapping Of The Northwestern Willamette Valley, Oregon, And Its American Viticultural Areas (Avas)— A Foundation For Understanding Their Terroir, Ray E. Wells, Ralph Haugerud, Alan Niem, Lina Ma, Ian Madin, Russell Evarts Jan 2018

New Geologic Mapping Of The Northwestern Willamette Valley, Oregon, And Its American Viticultural Areas (Avas)— A Foundation For Understanding Their Terroir, Ray E. Wells, Ralph Haugerud, Alan Niem, Lina Ma, Ian Madin, Russell Evarts

Geology Faculty Publications and Presentations

A geologic map of the greater Portland, Oregon, metropolitan area is planned that will document the region’s complex geology (currently in review: “Geologic map of the greater Portland metropolitan area and surrounding region, Oregon and Washington,” by Wells, R.E., Haugerud, R.A., Niem, A., Niem, W., Ma, L., Evarts, R., Madin, I., and others). The map, which is planned to be published as a U.S. Geological Survey Scientific Investigations Map, will consist of 51 7.5′ quadrangles covering more than 2,500 square miles, and it will represent more than 100 person-years of geologic mapping and studies. The region was mapped at the …


U.S. Geological Survey (Usgs) Topographic Map Collection, Kentucky Library Research Collections Jan 2018

U.S. Geological Survey (Usgs) Topographic Map Collection, Kentucky Library Research Collections

Research Collections

This is a listing of the Topo maps housed in the KLRC; 7.5, 15 and 30 minute Kentucky and Boundary State Maps. These maps are helpful in genealogy to show how the landscape may have changed and they may have the locations of lost towns and cemeteries and indicate houses, barns, and other structures and how place names, roads, and streams changed over time.


Performance Of The Grout Curtain At The Kentucky River Lock And Dam No. 8, Robert C. Hatton Jan 2018

Performance Of The Grout Curtain At The Kentucky River Lock And Dam No. 8, Robert C. Hatton

Theses and Dissertations--Civil Engineering

Karst bedrock conditions and deterioration of the lock and dam structures have resulted in significant leakage through, underneath, and around Lock and Dam No. 8 on the Kentucky River. During severe droughts, the water surface in Pool No. 8 has been observed to drop below the crest of the dam, resulting in water supply shortages and water quality issues for surrounding communities reliant on the pool. Presently, the primary purpose of Lock and Dam No. 8 is water supply. Pool No. 8 is currently where the cities of Nicholasville (Jessamine County, KY) and Lancaster (Garrard County, KY) draw their water. …


Stratigraphy And Organic Geochemistry Reveal Patterns Of Late Quaternary Paleo-Productivity At Mono Lake, California, Bailee Nicole Hodelka Jan 2018

Stratigraphy And Organic Geochemistry Reveal Patterns Of Late Quaternary Paleo-Productivity At Mono Lake, California, Bailee Nicole Hodelka

Theses and Dissertations--Earth and Environmental Sciences

Mono Lake (CA) is a hydrologically closed lacustrine basin well-known for its paleo-shorelines, which record fluctuations in water level for the last deglacial and late Holocene. Mono Lake is a sentinel of California’s water supply, situated in the rain shadow of the Sierra Nevada, a mountain range whose snowpack is a vital source of freshwater for urban and agricultural districts to the west and south. Recent droughts, floods, and wildfires show that California is threatened by climate change, but how these changes impact and get recorded by Mono Lake sediments remains poorly known. Here, we use a new radiocarbon-dated deepwater …


Occurrence And Attributes Of Two Echinoderm-Bearing Faunas From The Upper Mississippian (Chesterian; Lower Serpukhovian) Ramey Creek Member, Slade Formation, Eastern Kentucky, U.S.A., Ann Well Harris Jan 2018

Occurrence And Attributes Of Two Echinoderm-Bearing Faunas From The Upper Mississippian (Chesterian; Lower Serpukhovian) Ramey Creek Member, Slade Formation, Eastern Kentucky, U.S.A., Ann Well Harris

Theses and Dissertations--Earth and Environmental Sciences

Well-preserved echinoderm faunas are rare in the fossil record, and when uncovered, understanding their occurrence can be useful in interpreting other faunas. In this study, two such faunas of the same age from separate localities in the shallow-marine Ramey Creek Member of the Slade Formation in the Upper Mississippian (Chesterian) rocks of eastern Kentucky are examined. Of the more than 5,000 fossil specimens from both localities, only 9–34 percent were echinoderms from 3–5 classes. Nine non-echinoderm (8 invertebrate and one vertebrate) classes occurred at both localities, but of these, bryozoans, brachiopods and sponges dominated. To understand the attributes of both …


Hydrologic Monitoring And 2-D Electrical Resistivity Imaging For Joint Geophysical And Geotechnical Characterization Of Shallow Colluvial Landslides, Matthew M. Crawford Jan 2018

Hydrologic Monitoring And 2-D Electrical Resistivity Imaging For Joint Geophysical And Geotechnical Characterization Of Shallow Colluvial Landslides, Matthew M. Crawford

Theses and Dissertations--Earth and Environmental Sciences

Landslide characterization and hazard assessments require multidisciplinary approaches that connect geologic processes with geotechnical parameters. Field monitoring of hydrologic variables such as water content and water potential, coupled with geoelectrical measurements that can establish relationships used for geotechnical and landslide hazard investigations is deficient.

This study brings together different techniques to develop a methodology that connects geoelectrical measurements and shear strength. A field-based framework was established that includes (1) analysis of long-term soil moisture fluctuations within different landslides (2) establishment of constitutive and new equations that test the use of electrical conductivity to predict soil-water relationships and shear strength (3) …


A Multi-Indicator Approach To Understanding The Diagenesis Of Carbonates In Pennsylvanian Mudrocks Of The Midland Basin, Alex J. Reis Jan 2018

A Multi-Indicator Approach To Understanding The Diagenesis Of Carbonates In Pennsylvanian Mudrocks Of The Midland Basin, Alex J. Reis

Theses and Dissertations--Earth and Environmental Sciences

The Late Pennsylvanian was a time of frequent, rapid glacioeustatic sea-level changes. These changes were recorded in the Wolfcamp D Formation of the Midland Basin as a series of cyclothems similar to those studied in the Midcontinent region (e.g., Algeo and Heckel, 2008). This study focuses on identifying the mechanisms and controls on carbonate deposition and diagenesis through the Upper Pennsylvanian Wolfcamp D Formation and evaluating the potential for these layers to be stratigraphically significant. A stepwise progression of diagenetic processes was identified through the use of δ13Ccarb and δ18Ocarb, bulk geochemical and …


Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel Jan 2018

Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel

Dissertations and Theses

Asteroid bombardment contributed to extensive melting and resurfacing of ancient (> 3 Ga) Mars, thereby influencing the early evolution of the Martian crust. However, information about how impact melting has altered Mars’ crustal petrology is limited. Evidence from some of the largest impact structures on Earth, such as Sudbury and Manicouagan, suggests that some impact melt sheets experience chemical differentiation. If these processes occur on Mars, we expect to observe differentiated igneous materials in some exhumed rock samples. Some rocks observed in Gale crater are enriched in alkalis (up to 14 wt% Na2O + K2O) and …


Osteohistology And Skeletochronology Of An Ontogenetic Series Of Clidastes (Squamata: Mosasauridae): Growth And Metabolism In Basal Mosasaurids, Cyrus C. Green Jan 2018

Osteohistology And Skeletochronology Of An Ontogenetic Series Of Clidastes (Squamata: Mosasauridae): Growth And Metabolism In Basal Mosasaurids, Cyrus C. Green

Master's Theses or Doctor of Nursing Practice

Clidastes was a large marine reptile from the Late Cretaceous Western Interior Seaway of North America. Though the remains of Clidastes have been found in the Cretaceous chalks and shales for over 150 years, little is known about their growth rates.

Osteohistology is a well-documented technique used to investigate growth in extinct animals. Previous histological studies of Clidastes have hypothesized higher growth rates in basal mosasaurids than varanids due to higher vascularity. These studies focused on adult specimens but did not look at ontogenetic changes in growth rates. Isotopic studies of Clidastes indicate high metabolic temperatures, leading to speculation these …


Ground Deformation Studies And Evacuation Behavior During Eruptions At Guatemalan Volcanoes, Hans Lechner Jan 2018

Ground Deformation Studies And Evacuation Behavior During Eruptions At Guatemalan Volcanoes, Hans Lechner

Dissertations, Master's Theses and Master's Reports

Volcanic eruptions can be an especially problematic hazard when considering the uncertainty in eruption timing and magnitude coupled with challenges associated with delivering warnings to remote areas and facilitating effective evacuations. The hazards presented by Guatemala’s active volcanoes demand enhanced monitoring capabilities and instrumentation infrastructure. Strengthening the link between the physical and social sciences should lead to more accurate, reliable, and timely hazard information to the people living in proximity to the volcano and facilitate rational decisions and actions that reduce their level of risk. While there is no one single technique that can provide unambiguous diagnostics about the timing, …


Spectral Signatures Of Submicron Scale Light-Absorbing Impurities In Snow And Ice Using Hyperspectral Microscopy, Farra Dal Anna, Susan Kaspari, James Beach, Thomas D. Bucheli, Michael Schaepman, Margit Schwikowski Jan 2018

Spectral Signatures Of Submicron Scale Light-Absorbing Impurities In Snow And Ice Using Hyperspectral Microscopy, Farra Dal Anna, Susan Kaspari, James Beach, Thomas D. Bucheli, Michael Schaepman, Margit Schwikowski

Geological Sciences Faculty Scholarship

Light-absorbing impurities (LAI) can darken snow and ice surfaces, reduce snow/ice albedo and accelerate melt. Efforts to allocate the relative contribution of different LAI to snow/ice albedo reductions have been limited by uncertainties in the optical properties of LAI. We developed a new method to measure LAI spectral reflectance at the submicron scale by modifying a Hyperspectral Imaging Microscope Spectrometer (HIMS). We present the instrument’s internal calibration, and the overall small influence of a particle’s orientation on its measured reflectance spectrum. We validated this new method through the comparison with a field spectroradiometer by measuring different standard materials. Measurements with …


A Shift From Drought To Extreme Rainfall Drives A Stable Landslide To Catastrophic Failure, Alexander L. Handwerger, Mong-Han Haung, Eric Jameson Fielding, Adam M. Booth, Roland Burgmann Jan 2018

A Shift From Drought To Extreme Rainfall Drives A Stable Landslide To Catastrophic Failure, Alexander L. Handwerger, Mong-Han Haung, Eric Jameson Fielding, Adam M. Booth, Roland Burgmann

Geology Faculty Publications and Presentations

The addition of water on or below the earth’s surface generates changes in stress that can trigger both stable and unstable sliding of landslides and faults. While these sliding behaviours are well-described by commonly used mechanical models developed from laboratory testing (e.g., critical-state soil mechanics and rate-and-state friction), less is known about the field-scale environmental conditions or kinematic behaviours that occur during the transition from stable to unstable sliding. Here we use radar interferometry (InSAR) and a simple 1D hydrological model to characterize 8 years of stable sliding of the Mud Creek landslide, California, USA, prior to its rapid acceleration …


Glacier Recession And The Response Of Summer Streamflow In The Pacific Northwest United States, 1960–2099, Chris Frans, Erkan Istanbulluoglu, Dennis P. Lettenmaier, Andrew G. Fountain, Jon L. Riedel Jan 2018

Glacier Recession And The Response Of Summer Streamflow In The Pacific Northwest United States, 1960–2099, Chris Frans, Erkan Istanbulluoglu, Dennis P. Lettenmaier, Andrew G. Fountain, Jon L. Riedel

Geology Faculty Publications and Presentations

The Pacific Northwest is the most highly glacierized region in the conterminous United States (858 glaciers; 466 km2). These glaciers have displayed ubiquitous patterns of retreat since the 1980s mostly in response to warming air temperatures. Glacier melt provides water for downstream uses including agricultural water supply, hydroelectric power generation, and for ecological systems adapted to cold reliable streamflow. While changes in glacier area have been studied within the region over an extended period of time, the hydrologic consequences of these changes are not well defined. We applied a high‐resolution glacio‐hydrological model to predict glacier mass balance, glacier area, and …


The Littlefield Rhyolite And Associated Mafic Lavas: Bimodal Volcanism Of The Columbia River Magmatic Province, With Constraints On Age And Storage Sites Of Grande Ronde Basalt Magmas, Brian Mcculloch Webb, Martin J. Streck, William C. Mcintosh, Mark L. Ferns Jan 2018

The Littlefield Rhyolite And Associated Mafic Lavas: Bimodal Volcanism Of The Columbia River Magmatic Province, With Constraints On Age And Storage Sites Of Grande Ronde Basalt Magmas, Brian Mcculloch Webb, Martin J. Streck, William C. Mcintosh, Mark L. Ferns

Geology Faculty Publications and Presentations

We present data that distinguishes the long-known Littlefield Rhyolite of eastern Oregon (northwestern United States) into two distinct, voluminous, Snake River–type, high-temperature rhyolite lava packages that erupted in short sequence overk.y., with minimum volumes of 100 and 150 km3 respectively, contemporaneous with flood basalt volcanism of the Grande Ronde Basalt phase of the Columbia River Basalt Group. Contemporaneity of rhyolites with flood basalts is exceptionally demonstrated within the Malheur Gorge by intercalated mafic units belonging to the Grande Ronde Basalt that are stratigraphically constrained by underlying and overlying Littlefield Rhyolite flows, and the underlying Dinner Creek Tuff (unit 1). Our …


Zircon U-Pb Geochronology Of Two Basement Cores (Kentucky, Usa): Implications For Late Mesoproterozoic Sedimentation And Tectonics In The Eastern Midcontinent, David P. Moecher, J. Richard Bowersox, John B. Hickman Jan 2018

Zircon U-Pb Geochronology Of Two Basement Cores (Kentucky, Usa): Implications For Late Mesoproterozoic Sedimentation And Tectonics In The Eastern Midcontinent, David P. Moecher, J. Richard Bowersox, John B. Hickman

Earth and Environmental Sciences Faculty Publications

Basement cores from two wells drilled west and east of the Grenville front consist of feldspathic litharenite and granitic orthogneiss, respectively. Detrital zircon U-Pb ages for the litharenite define a broad dominant U-Pb age mode at ca. 1115 Ma. The dominant mode matches that for the type locality of the Middle Run Formation in the Ohio subsurface and is interpreted to consist of detrital zircons sourced from East Continent Rift volcanic sources (ca. 1100 Ma) and Grenville Shawinigan granites/gneisses (1120–1180 Ma). The youngest detrital zircon ages (ca. 1020 Ma) require a maximum depositional age that is at least 70 My …


On The Spatial Modelling Of Mixed And Constrained Geospatial Data, Hassan Talebi Jan 2018

On The Spatial Modelling Of Mixed And Constrained Geospatial Data, Hassan Talebi

Theses: Doctorates and Masters

Spatial uncertainty modelling and prediction of a set of regionalized dependent variables from various sample spaces (e.g. continuous and categorical) is a common challenge for geoscience modellers and many geoscience applications such as evaluation of mineral resources, characterization of oil reservoirs or hydrology of groundwater. To consider the complex statistical and spatial relationships, categorical data such as rock types, soil types, alteration units, and continental crustal blocks should be modelled jointly with other continuous attributes (e.g. porosity, permeability, seismic velocity, mineral and geochemical compositions or pollutant concentration). These multivariate geospatial data normally have complex statistical and spatial relationships which should …