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Articles 811 - 840 of 2252

Full-Text Articles in Geomorphology

Controls On Dissolution Rate Variation At A Pair Of Underflow-Overflow Springs At The Savoy Experimental Watershed, Kiefer Allen Vaughn May 2015

Controls On Dissolution Rate Variation At A Pair Of Underflow-Overflow Springs At The Savoy Experimental Watershed, Kiefer Allen Vaughn

Graduate Theses and Dissertations

Physical dissolution experiments and numerical modeling have been used in the past to study limestone dissolution rates. Numerical models have typically used constant dissolution rates, whereas rates in nature vary in time. Limestone tablets allow natural estimation of rates over month time scales, but these rates cannot necessarily be extrapolated to geologic timescales and also do not aid our understanding of short term variability. This study characterizes natural variability in these rates and examines potential causes of that variability from first principles. This may enable more accurate projections of dissolution rates within models. This study combines measurement of physical and …

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Hydrologic Mediation Of The Spatial And Temporal Variability Of The Soil Carbon Dioxide Stable Isotopic Composition Of A Subalpine Watershed, Theresa Marie Lorenzo May 2015

Hydrologic Mediation Of The Spatial And Temporal Variability Of The Soil Carbon Dioxide Stable Isotopic Composition Of A Subalpine Watershed, Theresa Marie Lorenzo

School of Natural Resources: Dissertations, Theses, and Student Research

The stable carbon isotopic composition of CO2 (δ13C-CO2) has been studied as an indicator of changes in ecosystem CO2 exchange. Soil moisture is an important factor in ecosystem CO2 exchange through its influence on physiological and soil physical processes. However, the majority of previous research analyzing the influence of soil moisture on soil and soil-respired δ13C-CO2 has been conducted with limited consideration of topographical variation, which controls the distribution of soil moisture across a landscape. This study characterized the stable isotopic composition (δ13C) and concentrations of soil CO …

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Basic Guide For Description Of Cuttings From Boreholes In Nebraska, Dana P. Divine, R. M. Joeckel, Jesse T. Korus May 2015

Basic Guide For Description Of Cuttings From Boreholes In Nebraska, Dana P. Divine, R. M. Joeckel, Jesse T. Korus

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Comparing Slug Test Methods For Unconfined Aquifers, Hussain Jaber Alfaifi May 2015

Comparing Slug Test Methods For Unconfined Aquifers, Hussain Jaber Alfaifi

Dissertations

Slug test methods are used to determine in situ aquifer hydraulic conductivity (K) more quickly and economically than a pump test can. This study compares slug test methods for unconfined aquifers, looking at how to conduct a test using a physical slug, and at different analysis methods including Bouwer and Rice (1976), Kansas Geological Survey (KGS 1994), Hvorslev (1951) and Dagan (1978). Questions that motivated this study include: How well does the Bouwer and Rice method work? What is the most effective way to conduct a slug test? Does using a large physical slug relative to the well diameter and …

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Fault Zone Hydrogeology In Crystalline And Sedimentary Aquifers In Arid Regions: Remote Sensing, Hydrological And Geoloectrical Methods, Lamees M. Mohamed Apr 2015

Fault Zone Hydrogeology In Crystalline And Sedimentary Aquifers In Arid Regions: Remote Sensing, Hydrological And Geoloectrical Methods, Lamees M. Mohamed

Research and Creative Activities Poster Day

An integrated study was conducted using remote sensing, hydrological and geophysical methods to investigate the role of structural elements in controlling the groundwater accumulation and flow in fractured basement complex. This research shows that the structural elements as fault and shear zones could act as a conduit or a barrier for the groundwater depending on the direction of these elements with the groundwater flow. Similar findings are observed in Central Sinai as it was found in Southern Sinai. These findings will help in more understanding of the fractured basement aquifers.

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Longitudinal Profile And Sediment Mobility As Geomorphic Tools To Interpret The History Of A Fluviokarst Stream System, John Woodside, Eric Wade Peterson, Toby Dogwiler Apr 2015

Longitudinal Profile And Sediment Mobility As Geomorphic Tools To Interpret The History Of A Fluviokarst Stream System, John Woodside, Eric Wade Peterson, Toby Dogwiler

International Journal of Speleology

The complex drainage systems within karst settings can result in atypical longitudinal profiles. Features, such as cave entrances, can be expressed as anomalous ‘bumps’ in the longitudinal profile of a stream if downcutting has continued upstream of the area in which the water is pirated to the subsurface. Horn Hollow, a fluviokarst valley located in Carter Caves State Park Resort in northeastern Kentucky, was examined for these types of features. The objectives of this study were to determine if sediment mobility can be used as a proxy for anomalous areas along the profile of the valley and if detailed cross-sections …

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Landforms Along The Lower Columbia River And The Influence Of Humans, Charles Matthew Cannon Apr 2015

Landforms Along The Lower Columbia River And The Influence Of Humans, Charles Matthew Cannon

Dissertations and Theses

River systems, such as the Columbia River in the Pacific Northwest, USA have been influenced by human activities, resulting in changes to the physical processes that drive landform evolution. This work describes an inventory of landforms along the Columbia River estuary between the Pacific Ocean and Bonneville Dam in Oregon and Washington. Groupings of landforms are assigned to formative process regimes that are used to assess historical changes to floodplain features. The estuary was historically a complex system of channels with a floodplain dominated by extensive tidal wetlands in the lower reaches and backswamp lakes and wetlands in upper reaches. …

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An Investigation To Remotely Sense Mineral Leeching Through Soils, Paul C. Shaffer Apr 2015

An Investigation To Remotely Sense Mineral Leeching Through Soils, Paul C. Shaffer

Thinking Matters Symposium Archive

Satellite data on Earth's surface provide a wealth of information on landscape conditions. I use Landsat data to determine an important geologic process that influences the composition of the soils. My project focusses on the experimental hypothesis that we can use plant vigor as a proxy to document mineral washing downslopes through soils. I constructed a Normalized Difference Vegetation Index (NDVI) composite image from Landsat data to help assess vegetation heath in my target location - a national park south of Mount St. Helens. This location was selected because of its steep inclines, dense undisturbed vegetation, and fertile soils. It …

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Morphodynamics Of Mullet Key, West-Central Florida, Emeli Sandoval Mar 2015

Morphodynamics Of Mullet Key, West-Central Florida, Emeli Sandoval

USF Tampa Graduate Theses and Dissertations

Mullet Key is a right angle barrier island located at the mouth of Tampa Bay, west-central Florida. Based on historical shoreline data from 1873, the Gulf (west)-facing section of the beach has been dynamic illustrating large beach advances and retreats of up to 500 m on a decadal scale, while the south (channel)-facing section of the beach has shown to maintain a stable shoreline. This study focuses on the morphodynamics of the Gulf-facing beach. Since the 1920s, most of the Gulf-facing beach has been accreting except at the southern end near the Tampa Bay main channel. However, over the past …

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Karst Porosity Estimations From Archive Cave Surveys - Studies In The Buda Thermal Karst System (Hungary), Gáspár Albert, Magdolna Virág, Anita Erőss Feb 2015

Karst Porosity Estimations From Archive Cave Surveys - Studies In The Buda Thermal Karst System (Hungary), Gáspár Albert, Magdolna Virág, Anita Erőss

International Journal of Speleology

The Buda Thermal Karst System is located under the densely populated hills of Budapest. One of its caves (Pál-völgy Cave System) is the longest cave of Hungary with 30.1 km. The research was done in this area as a methodological study to estimate karst porosity parameters of aquifers or hydrocarbon reservoirs. In this study two modeling methods are demonstrated. The volumetric modeling method was primarily aimed to determine the macro-scale (>0.5 m) conduit porosity (referred as macroporosity) of the study area as percentage of the incorporating limestone and marl. This method is based on archive survey data (maps and …

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Beyond The Angle Of Repose: A Review And Synthesis Of Landslide Processes In Response To Rapid Uplift, Eel River, Northern Eel River, Northern California, Joshua J. Roering, Benjamin H. Mackey, Alexander L. Handwerger, Adam M. Booth, David A. Schmidt, Georgina L. Bennett, Corina Cerovski-Darriau Feb 2015

Beyond The Angle Of Repose: A Review And Synthesis Of Landslide Processes In Response To Rapid Uplift, Eel River, Northern Eel River, Northern California, Joshua J. Roering, Benjamin H. Mackey, Alexander L. Handwerger, Adam M. Booth, David A. Schmidt, Georgina L. Bennett, Corina Cerovski-Darriau

Geology Faculty Publications and Presentations

In mountainous settings, increases in rock uplift are often followed by a commensurate uptick in denudation as rivers incise and steepen hillslopes, making them increasingly prone to landsliding as slope angles approach a limiting value. For decades, the threshold slope model has been invoked to account for landslide-driven increases in sediment flux that limit topographic relief, but the manner by which slope failures organize themselves spatially and temporally in order for erosion to keep pace with rock uplift has not been well documented. Here, we review past work and present new findings from remote sensing, cosmogenic adionuclides, suspended sediment records, …

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Estimation Of Offsets In Gps Time-Series And Application To The Detection Of Earthquake Deformation In The Far-Field, Jean-Philippe Montillet, S. D. P. Williams, A. Koulali, S. C. Mcclusky Jan 2015

Estimation Of Offsets In Gps Time-Series And Application To The Detection Of Earthquake Deformation In The Far-Field, Jean-Philippe Montillet, S. D. P. Williams, A. Koulali, S. C. Mcclusky

All Faculty Scholarship for the College of the Sciences

Extracting geophysical signals from Global Positioning System (GPS) coordinate time-series is a well-established practice that has led to great insights into how the Earth deforms. Often small discontinuities are found in such time-series and are traceable to either broad-scale deformation (i.e. earthquakes) or discontinuities due to equipment changes and/or failures. Estimating these offsets accurately enables the identification of coseismic deformation estimates in the former case, and the removal of unwanted signals in the latter case which then allows tectonic rates to be estimated more accurately. We develop a method to estimate accurately discontinuities in time series of GPS positions at …

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Morphological, Structural, And Spectral Characteristics Of Amorphous Iron Sulfates, Elizabeth Sklute, Heidi Jensen, Deanne Rogers, Richard Reeder Jan 2015

Morphological, Structural, And Spectral Characteristics Of Amorphous Iron Sulfates, Elizabeth Sklute, Heidi Jensen, Deanne Rogers, Richard Reeder

Department of Geosciences Faculty Publications

Current or past brine hydrologic activity on Mars may provide suitable conditions for the formation of amorphous ferric sulfates. Once formed, these phases would likely be stable under current Martian conditions, particularly at low- to mid-latitudes. Therefore, we consider amorphous iron sulfates (AIS) as possible components of Martian surface materials. Laboratory AIS were created through multiple synthesis routes and characterized with total X-ray scattering, thermogravimetric analysis, scanning electron microscopy, visible/near-infrared (VNIR), thermal infrared (TIR), and Mössbauer techniques. We synthesized amorphous ferric sulfates (Fe(III)2(SO4)3 · ~ 6–8H2O) from sulfate-saturated fluids via vacuum dehydration or exposure to low relative humidity (

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Cars And Karst: Investigating The National Corvette Museum Sinkhole, Jason S. Polk, Leslie North, Ric Federico, Brian Ham, Dan Nedvidek, Kegan Mcclanahan, Pat Kambesis, Michael Marasa Jan 2015

Cars And Karst: Investigating The National Corvette Museum Sinkhole, Jason S. Polk, Leslie North, Ric Federico, Brian Ham, Dan Nedvidek, Kegan Mcclanahan, Pat Kambesis, Michael Marasa

Earth, Environmental, and Atmospheric Sciences Faculty Publications

On February 12th, 2014, a sinkhole occurred at the National Corvette Museum in Bowling Green, Kentucky. The collapse happened inside part of the building known as the Skydome and eight Corvettes on display were lost into the void that opened in the concrete floor. In this region of Kentucky, known as the Pennyroyal sinkhole plain, subsidence and cover collapse sinkholes are commonly found throughout the landscape. This iconic karst region in the United States is also home to Mammoth Cave, the longest cave in the world, and thousands of other caves and karst features. Investigation of the sinkhole collapse began …

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Identification And Quantification Of Diffuse Fresh Submarine Groundwater Discharge Via Airborne Thermal Infrared Remote Sensing, Joseph T. Tamborski, A Deanne Rogers, Henry J. Bokuniewicz, J Kirk Cochran, Caitlin R. Young Jan 2015

Identification And Quantification Of Diffuse Fresh Submarine Groundwater Discharge Via Airborne Thermal Infrared Remote Sensing, Joseph T. Tamborski, A Deanne Rogers, Henry J. Bokuniewicz, J Kirk Cochran, Caitlin R. Young

Department of Geosciences Faculty Publications

Airborne thermal infrared (TIR) overflights were combined with shoreline radionuclide surveys to investigate submarine groundwater discharge (SGD) along the north shore of Long Island, NY between June 2013 and September 2014. Regression equations developed for three distinct geomorphological environments suggest a positive linear relationship between the rate of diffuse SGD and the spatial extent of the observed coastal TIR anomalies; such a relationship provides quantitative evidence of the ability to use TIR remote sensing as a tool to remotely identify and measure SGD. Landsat TIR scenes were unable to resolve any of the 18 TIR anomalies identified during the various …

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Feldspathic Rocks On Mars: Compositional Constraints From Infrared Spectroscopy And Possible Formation Mechanisms, Deanne Rogers, Hanna Nekvasil Jan 2015

Feldspathic Rocks On Mars: Compositional Constraints From Infrared Spectroscopy And Possible Formation Mechanisms, Deanne Rogers, Hanna Nekvasil

Department of Geosciences Faculty Publications

Rare feldspar-dominated surfaces on Mars were previously reported based on near-infrared (NIR) spectral data and were interpreted to consist of anorthosite or felsic rocks. Using thermal infrared (TIR) data over the feldspar detections with the largest areal extent in Nili Patera and Noachis Terra, we rule out felsic interpretations. Basaltic or anorthositic compositions are consistent with TIR measurements, but the geologic contexts for these regions do not support a plutonic origin. Laboratory NIR spectral measurements demonstrate that large plagioclase crystals (>~840 μm) can be detected in mixtures with as much as 50 vol % mafics, which is higher than …

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The Relationship Between Particle Travel Distance And Channel Morphology: Results Fromphysicalmodels Of Braided Rivers, Alan Kasprak, Joseph Wheaton, Peter Ashmore, James Hensleigh, Sarah Peirce Jan 2015

The Relationship Between Particle Travel Distance And Channel Morphology: Results Fromphysicalmodels Of Braided Rivers, Alan Kasprak, Joseph Wheaton, Peter Ashmore, James Hensleigh, Sarah Peirce

Geography & Environment Publications

Channel form and sediment transport are closely linked in alluvial rivers, and as such the development of a conceptual framework for the downstream controls on particle mobility and likely deposition sites has immense value in terms of the way we understand and predictively model rivers. Despite the development of conceptual models which frame flood-scale particle transport distance (termed path length) as a function of channel bar locations, an understanding of the controls on such path lengths in braided rivers remains especially elusive, in large part due to the difficulty in explicitly linking morphology and particle transport distances in the field. …

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Anthropogenic Controls On Overwash Deposition: Evidence And Consequences, Laura Rogers, Laura Moore, Evan Goldstein, Christopher Hein, Jorge Lorenzo Trueba, Andrew Ashton Jan 2015

Anthropogenic Controls On Overwash Deposition: Evidence And Consequences, Laura Rogers, Laura Moore, Evan Goldstein, Christopher Hein, Jorge Lorenzo Trueba, Andrew Ashton

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Accelerated sea level rise and the potential for an increase in frequency of the most intense hurricanes due to climate change threaten the vitality and habitability of barrier islands by lowering their relative elevation and altering frequency of overwash. High-density development may further increase island vulnerability by restricting delivery of overwash to the subaerial island. We analyzed pre-Hurricane Sandy and post-Hurricane Sandy (2012) lidar surveys of the New Jersey coast to assess human influence on barrier overwash, comparing natural environments to two developed environments (commercial and residential) using shore-perpendicular topographic profiles. The volumes of overwash delivered to residential and commercial …

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The Groundwater Atlas Of Saunders County, Nebraska, Dana Divine Jan 2015

The Groundwater Atlas Of Saunders County, Nebraska, Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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The Geologic Context Of Landslide And Rockfall Maintenance Costs In Kentucky, Bethany L. Overfield, Daniel I. Carey, Gerald A. Weisenfluh, Rebecca Wang, Matthew M. Crawford Jan 2015

The Geologic Context Of Landslide And Rockfall Maintenance Costs In Kentucky, Bethany L. Overfield, Daniel I. Carey, Gerald A. Weisenfluh, Rebecca Wang, Matthew M. Crawford

Report of Investigations--KGS

Kentucky Transportation Cabinet maintenance cost data for landslides and rockfalls were associated with geology along Kentucky roadways in a three-phase study. Work-order costs collected over 7 yr were divided into 1-mi segments, and the segment midpoints were assigned to geologic formation. Formations that were expensive to maintain were not necessarily those that were the most frequently repaired and vice versa. Costs and frequency of repair were greater in eastern and northern Kentucky, where slope and relief are greater than in other parts of the state and shale-bearing geologic units prevail.

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Channel Morphology At A Meander Bend Chute Cutoff Partially Obstructed By Woody Debris, Drew Sobczak Jan 2015

Channel Morphology At A Meander Bend Chute Cutoff Partially Obstructed By Woody Debris, Drew Sobczak

Masters Theses

Field and flume experiments have examined the conceptual model for a meander bend in depth. Large woody debris piles are often associated with the development of a chute cutoff due to local aggradation and deflection of flow. This paper examines the bed morphology of a meander bend chute cutoff that is partially obstructed by woody debris. The bed morphology of the channel around the woody debris pile as well as the head of the cutoff are mapped. The pile is shielding the point bar immediately behind it and causing a narrow, deep channel on either side of the pile. The …

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Ecohydraulic Investigation Of Diatoms In A Bedrock-Controlled Stream, Alex M. Rittle Jan 2015

Ecohydraulic Investigation Of Diatoms In A Bedrock-Controlled Stream, Alex M. Rittle

Theses and Dissertations--Geography

Recent studies within the past decade or so have shown the importance of algae in geomorphic and hydrologic processes of lotic systems. However, the ecohydraulic role of algae in bedrock systems has largely been ignored. In addition, the utility of algae as indicators of channel dynamics have often been assumed by geomorphologists, but relatively few studies have examined this relationship. The purpose of this study was to determine whether algae, specifically diatoms, are useful indicators of channel geomorphological dynamics, and to examine if distinct habitats or biotopes typical in fluviokarst and bedrock systems provide unique habitat space for diatoms, and …

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North-Central Nebraska Geology: Niobrara River Valley In Brown, Cherry, And Keya Paha Counties, R. M. Joeckel, L. M. Howard, S T. Tucker Jan 2015

North-Central Nebraska Geology: Niobrara River Valley In Brown, Cherry, And Keya Paha Counties, R. M. Joeckel, L. M. Howard, S T. Tucker

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Nebraska Statewide Groundwater-Level Monitoring Report 2015, A. R. Young, M. E. Burbach, L. M. Howard Jan 2015

Nebraska Statewide Groundwater-Level Monitoring Report 2015, A. R. Young, M. E. Burbach, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Assessing The Relative Mobility Of Submarine Landslides From Deposit Morphology And Physical Properties: An Example From Kumano Basin, Nankai Trough, Offshore Japan, Zachary T. Moore Jan 2015

Assessing The Relative Mobility Of Submarine Landslides From Deposit Morphology And Physical Properties: An Example From Kumano Basin, Nankai Trough, Offshore Japan, Zachary T. Moore

Theses and Dissertations--Earth and Environmental Sciences

A prominent landslide deposit in the Slope Basin seaward of the Megasplay Fault in the Nankai Trough was emplaced by a high-mobility landslide based on analysis of physical properties and seismic geomorphology. Slide acceleration is a critical variable that determines amplitude of slide-generated tsunami but is many times a variable with large uncertainty. In recent controlled laboratory experiments, the ratio of the shear stress to yield strength (defined as the Flow Factor) controls a wide spectrum of mass movement styles from slow, retrogressive failure to rapid, liquefied flows. Here, we apply this laboratory Flow Factor approach to a natural landslide …

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Fluvial Responses To Growth Faulting In The West Pearl River, Louisiana, Stephen A. Prosser Jan 2015

Fluvial Responses To Growth Faulting In The West Pearl River, Louisiana, Stephen A. Prosser

Theses and Dissertations--Earth and Environmental Sciences

The Pearl River Delta (PRD) in southeastern Louisiana is an actively deforming deltaic complex displaying surface and near-surface evidence of growth faulting. Active growth faults in these environments are rarely identified at the surface, in part because the downthrown blocks often experience increased rates of sediment deposition leading to an obscured and low-relief, or entirely absent, surface expression. Faulting can be expressed in fluvial systems as changes in channel gradient, which often result in coincident changes in channel sinuosity, migration rates, planform deflections, and/or ponding features within the deformed zone. The study area is focused on a meander bend of …

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Geologic Map Of The Welcome Quadrangle And An Adjacent Part Of The Wells Quadrangle, Elko County, Nevada, Allen J. Mcgrew, Arthur W. Snoke Jan 2015

Geologic Map Of The Welcome Quadrangle And An Adjacent Part Of The Wells Quadrangle, Elko County, Nevada, Allen J. Mcgrew, Arthur W. Snoke

Department of Earth, Environment and Sustainability Faculty Publications

Located in central Elko County, the Welcome and adjacent part of the Wells quadrangles expose a remarkable array of critical relationships for understanding the geologic history of the State of Nevada and the interior of the southwestern U.S. Cordillera. Covering the northern end of the East Humboldt Range and adjacent Clover Valley and Clover Hill, this map includes the northern terminus of the Ruby Mountains-East Humboldt Range metamorphic core complex. The oldest rocks in the State of Nevada (the gneiss complex of Angel Lake), and Nevada’s only exposures of Archean rock, form the core of a multikilometer scale, southward-closing recumbent …

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Stream Bank Erosion Trends And Sediment Contributions In A Southwestern Missouri River, Ezekiel Allen Kuehn Jan 2015

Stream Bank Erosion Trends And Sediment Contributions In A Southwestern Missouri River, Ezekiel Allen Kuehn

Graduate Theses/Dissertations

Bank erosion can be a significant source of in-stream sediment that negatively affects water quality and aquatic habitat. However, assessments of the role that eroding banks play in suspended and bed sediment supply are rarely available to managers. The purpose of this study was to quantify bank erosion rates for a 7 km conservation easement the James River in southwest Missouri to evaluate the annual contributions of bank sediment to the channel. The objectives were to: (1) monitor an eroding 260 m bank to better understand short-term, reach scale bank erosion rates; (2) determine historical rates of bank erosion for …

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Sediment Routing Through Channel Confluences: Particle Tracing In A Gravel-Bed River Headwaters, Kurt Imhoff Jan 2015

Sediment Routing Through Channel Confluences: Particle Tracing In A Gravel-Bed River Headwaters, Kurt Imhoff

Graduate Student Theses, Dissertations, & Professional Papers

Sediment routing in gravel-bed rivers refers to the intermittent transport and storage of bedload particles, where short-duration steps are separated by periods of inactivity. Channel morphology governs sediment routing, but morphologic effects on routing in headwater systems are not well understood compared to lowland systems. RFID tracers are a valuable tool that can be employed to characterize routing processes in headwater channels through individual particle tracking. I present research on coarse sediment transport and dispersion through confluences using sediment tracers in the East Fork Bitterroot River basin, MT. I investigate the following questions: (1) How do sediment routing patterns through …

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Pressure-Temperature-Time Constraints For Exhumation Of Ultrahigh-Pressure Metamorphic Rocks, North Qaidam Terrane, Western China, Brittany Kristine Fagin Jan 2015

Pressure-Temperature-Time Constraints For Exhumation Of Ultrahigh-Pressure Metamorphic Rocks, North Qaidam Terrane, Western China, Brittany Kristine Fagin

All Master's Theses

Ultrahigh-pressure rocks of a Paleozoic continental suture zone are exposed in the southeastern North Qaidam terrane (Dulan region). Garnetite sample D119 contains minor Czo+Qtz+Chl+Ttn; rutile inclusions in titanite suggest that titanite replaced rutile during decompression. Pressure-temperature estimates of sample D119 are 16.1-18.4 kbar and 485-520 °C. Sample D130B is a mafic band in calc-silicate gneiss, with garnet porphyroblasts in a fine-grained Hbl-Cpx-Pl-Qtz symplectite that is interpreted as former omphacite. D130B symplectite pressure-temperature estimates are 7.7-9.4 kbar and 623-708 °C. Titanite U-Pb ages of 419.7±3.1 Ma and 415.9±4.2 Ma are interpreted to date retrogression of D119 and D130B, respectively. Average exhumation …

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