Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Hydrogeology

Discipline
Institution
Publication Year
Publication
Publication Type

Articles 61 - 90 of 214

Full-Text Articles in Earth Sciences

Evaluating Sources Of Hydrochemical Variability And Mixing In The Upper Gila River, New Mexico, Pavel Vakhlamov Jul 2019

Evaluating Sources Of Hydrochemical Variability And Mixing In The Upper Gila River, New Mexico, Pavel Vakhlamov

Earth and Planetary Sciences ETDs

This study of the upper reaches of the Gila River basin in southwestern New Mexico reveals both spatial and seasonal patterns in physical and hydrochemical parameters. Monsoonal precipitation, temporal variability in water chemistry of streams in the upper Gila watershed is significantly impacted by surface runoff due to variability in landscape cover features, as well as surface area of the catchment. However, during base flow regimes spring inputs are the dominant drivers of solute concentrations and chemical variability.

Geothermal sources play a major role in salinization of the southwestern stream systems. Prolonged water/rock interaction combined with high temperature, pressure result …


Investigation Of Pervasive Clay Layers And Their Effect On Groundwater Flow Using Electrical Resistivity Tomography In The San Antonio Groundwater Basin, James M. Carlson Jun 2019

Investigation Of Pervasive Clay Layers And Their Effect On Groundwater Flow Using Electrical Resistivity Tomography In The San Antonio Groundwater Basin, James M. Carlson

Natural Resources Management and Environmental Sciences

The United States Geological Survey is developing an integrated hydrologic model of the San Antonio Creek Groundwater Basin to better understand and simulate the integrated surface water and groundwater system. An abrupt 60 meter offset in groundwater depth over a distance of less than one kilometer is observed in well readings within the Cañada De Las Flores region of the groundwater basin. Abrupt changes in groundwater levels are often explained by the presence of a fault in the subsurface vertically offsetting sedimentary units. However, observations of the structural geology of this region indicates that faulting is unlikely and suggests an …


Investigations Of The Potential For Irrigated Agriculture On The Bonaparte Plains: Bore Completion Report, 2nd Edition, D L. Bennett Feb 2019

Investigations Of The Potential For Irrigated Agriculture On The Bonaparte Plains: Bore Completion Report, 2nd Edition, D L. Bennett

Resource management technical reports

Drilling programs were undertaken in 2013 and 2016 by the former Department of Agriculture and Food, Western Australia and in 2017 by DPIRD, at 10 sites in the Bonaparte Plains area, north of Kununurra in the East Kimberley region of Western Australia (WA).

These drilling programs were a component of resource availability and risk investigations conducted to determine the potential for developing irrigated agriculture on 30 000 hectares of Cockatoo Sands — free-draining loamy soils that have the potential to support crops in the wet and dry seasons. There was limited hydrogeological information available at a suitable scale for the …


Variability In Groundwater Flow And Chemistry In The Houzhai Karst Basin, Guizhou Province, China, Joshua M. Barna Jan 2019

Variability In Groundwater Flow And Chemistry In The Houzhai Karst Basin, Guizhou Province, China, Joshua M. Barna

Theses and Dissertations--Earth and Environmental Sciences

Understanding how karst aquifers store and transmit water and contaminants is an ongoing problem in hydrogeology. Flowpath and recharge heterogeneity contribute to the complexity of these systems. This thesis explores karst-conduit connectivity and water chemistry variability in the Houzhai catchment in Guizhou province, China. Artificial tracer tests were conducted during both the monsoon and dry seasons to understand temporal variability in connectivity and water velocity between karst features. Multiple flowpaths through the catchment are activated during the monsoon season and partially abandoned during the dry season. Additionally, gradient reversals during monsoonal high-flow events and as a result of pumping can …


Exploring The Northwest Margin Of The High Plains Aquifer: Structure, Depositional History And Hydrogeology, Nebraska Geological Society Field Trip, Doug Hallum, Dennis O. Terry, Jr., Michael Leite, Jennifer Balmat Jan 2019

Exploring The Northwest Margin Of The High Plains Aquifer: Structure, Depositional History And Hydrogeology, Nebraska Geological Society Field Trip, Doug Hallum, Dennis O. Terry, Jr., Michael Leite, Jennifer Balmat

Conservation and Survey Division: Faculty and Staff Publications

The northwest portion of the High Plains Aquifer in Nebraska corresponds with the western Sandhills, Box Butte, Sioux and Dawes County tablelands, and the Nebraska Pine Ridge in northwest Nebraska. This field excursion will travel beyond the margins of the High Plains aquifer into the White River valley and onto the Oglala National Grasslands. These areas are not only rich in natural resources, but rich in history as well. While this excursion will explore earth history, depositional environments and a portion of the High Plains Aquifer, the authors encourage all attendees to take additional time to explore the cultural, military …


Margaret White Springs Recharge Study, Buffalo National River, North-Central Arkansas, Usa, Ashlon Elizabeth Leonard Dec 2018

Margaret White Springs Recharge Study, Buffalo National River, North-Central Arkansas, Usa, Ashlon Elizabeth Leonard

Graduate Theses and Dissertations

Margaret White Springs (MWS) is one of the largest springs in the middle section of the Buffalo National River (BNR) and contributes several tens of cubic feet per second of flow to river discharge on average, yet the source of the water has not been fully studied or documented. The spring is located approximately 4 miles downstream from Robertson Hole, a losing reach of the river. At Robertson Hole the river loses a significant amount of flow to groundwater, which during the dry season (summer) can be as much as 100%. Flow in the main channel is re-established at MWS; …


Water Flow Net Characterization By Using A Tank Model: Preliminary Outcome, Jasmin Budhan, Nazrul I. Khandaker, Stanley Schleifer Nov 2018

Water Flow Net Characterization By Using A Tank Model: Preliminary Outcome, Jasmin Budhan, Nazrul I. Khandaker, Stanley Schleifer

Publications and Research

A model study was conducted to observe and characterize the flow of water through sandy soil. One of the most relevant tools used for characterizing groundwater flow is the flow net. Assuming that water is incompressible and there is zero volume change in the soil mass, it is known that the total rate of inflow is to equal the total rate of outflow. Thus, following the principle of flow continuity, we use the Laplace equation of continuity, to observe the concept of the flow net. Computing the flow through a miniature channel, we observed the total head difference from the …


Quantifying Carbon Dioxide Fluxes In The Air And Water In Blowing Springs Cave, Arkansas, Holly Young Aug 2018

Quantifying Carbon Dioxide Fluxes In The Air And Water In Blowing Springs Cave, Arkansas, Holly Young

Graduate Theses and Dissertations

Prior work has shown that the concentration of carbon dioxide (CO2) within cave atmospheres is a function of cave airflow patterns. The dynamics of CO2 within karst systems are of increasing interest as they can control periods of precipitation or dissolution in speleothems and influence potential interpretations of paleoclimate records. Similarly, CO2 is an important driver of speleogenesis, and air-water CO2 dynamics can control patterns of cave passage evolution. Karst also plays an uncertain role in the global carbon cycle and understanding CO2 dynamics within karst systems will aid the development of carbon budgets. Here, a monitoring station was deployed …


Numerical Modeling Of The Effects Of Land Use Change And Irrigation On Streamflow Depletion Of Frenchman Creek, Nebraska, Moussa Guira Jul 2018

Numerical Modeling Of The Effects Of Land Use Change And Irrigation On Streamflow Depletion Of Frenchman Creek, Nebraska, Moussa Guira

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

A three-dimensional Control Volume Finite Difference-based numerical groundwater flow model was constructed to assess the effects of agricultural irrigation and land use change on streamflow depletion. The study area is Frenchman Creek basin located in southwestern corner of the State of Nebraska, USA. This area was subject to an increased proliferation of groundwater abstraction for agricultural purposes since industrial revolution. It has also been subject to land use change from native rangeland to dry and irrigated cropland. The groundwater flow model was spatially discretized using Voronoi cells in unstructured grid built with the USGS MODFLOW-6. Temporal discretization defined 151 time …


Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer May 2018

Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer

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

Streambed hydraulic conductivity (K) is known to be spatially and temporally heterogeneous, but few attempts to understand the controls on temporal variability have been made. This study documents temporal K transience and demonstrates how hydraulic, geophysical, and sedimentological methods can be combined to understand the processes that give rise to changes in streambed K. Falling head permeameter tests and slug tests were conducted to determine vertical K (Kv) and K (slug test K), respectively. These tests were repeated three times over a twelve-week period on the same grid at a depth of 0.5 …


Structural Classification Using Aeromagnetic Data And Pseudogravity Transforms: A Case Study Of Pategi Area Of Bida Basin, Nigeria, Ayodele K Olawuyi, Halima M Amir, Mkabwa Lk Manoko Apr 2018

Structural Classification Using Aeromagnetic Data And Pseudogravity Transforms: A Case Study Of Pategi Area Of Bida Basin, Nigeria, Ayodele K Olawuyi, Halima M Amir, Mkabwa Lk Manoko

Tanzania Journal of Science

The structural classification with 3D Euler deconvolution method in the Pategi area, a transition environment between the Basement complex rocks of the southwestern Nigeria and the Sedimentary rocks of the Nupe Basin was carried out. It was aimed at identification of the structural features responsible for the hydrogeology and mineralization potentials of the area. This work involves the qualitative and quantitative analysis of aeromagnetic data and pseudogravity transforms using Oasis MontajTM. The 3-D Euler deconvolution of the acquired aeromagnetic data and pseudogravity transforms using Oasis montajTM software and the geologic information on this area was employed in the structural classification …


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 …


Estimating Groundwater Inflow And Age Characteristics In An Alluvial Aquifer Along The Little Wind River, Wyoming, Derek Goble Jan 2018

Estimating Groundwater Inflow And Age Characteristics In An Alluvial Aquifer Along The Little Wind River, Wyoming, Derek Goble

Graduate Student Theses, Dissertations, & Professional Papers

We synoptically sampled a 2 km gaining reach of the Little Wind River in central Wyoming for 222Rn, CFCs and SF6 to determine the distributed volumes and locations of discharge and estimate alluvial groundwater age characteristics. 222Rn was sampled in the stream, shallow in-stream piezometers and nearby alluvial groundwater wells to determine the volume and spatial distribution of groundwater discharge to the river. Age tracers, CFC and SF6, sampled in the stream, shallow in-stream piezometers and in alluvial groundwater wells were then used to determine whether in-stream samples are capable of constraining the residence time distribution …


Imaging Wetland Hydrogeophysics: Applications Of Critical Zone Hydrogeophysics To Better Understand Hydrogeologic Conditions In Coastal And Inland Wetlands And Waters, Christine Marie Downs Nov 2017

Imaging Wetland Hydrogeophysics: Applications Of Critical Zone Hydrogeophysics To Better Understand Hydrogeologic Conditions In Coastal And Inland Wetlands And Waters, Christine Marie Downs

USF Tampa Graduate Theses and Dissertations

This dissertation consists of three projects utilizing electric and electromagnetic (EM) methods to better understand critical-zone hydrogeologic conditions in select Florida wetlands and waters.

First, a time-lapse electrical resistivity (ER) survey was conducted in section of mangrove forest on a barrier island in southeast Florida to image changes in pore-water salinity in the root zone. ER data show the most variability in the root zone over a 24-hour period, and, generally, the ground is more resistive during the day than overnight.

Second, a suite of three-dimensional forward models, based on varying lateral boundaries and conductivities typical of a coastal wetland, …


The Application Of Aem To Mapping The Aquifer And Groundwater Characteristics Of The La Grange Groundwater Area, Wa, David Annetts, Tim Munday, Richard J. George Dr, Nicholas J. Wright, Gregory Paul Raper, Kevin Cahill Jul 2017

The Application Of Aem To Mapping The Aquifer And Groundwater Characteristics Of The La Grange Groundwater Area, Wa, David Annetts, Tim Munday, Richard J. George Dr, Nicholas J. Wright, Gregory Paul Raper, Kevin Cahill

Natural resources commissioned reports

This report describes the interpretation of a large airborne electromagnetic data survey that was designed to aid characterisation of groundwater systems in the La Grange groundwater allocation area which lies south of Broome, Western Australia. Characterisation of these systems is critical to developing policy around water use in the region, especially for the development of agriculture. This report is the second of two reports and it is designed to refine surfaces which are used as inputs to groundwater models. The volume defined by these surfaces viz. the seawater intrusion in the west, the top of the Jarlemai siltstone and the …


Isotope Investigation Of Nitrate In Soils And Agricultural Drain Waters Of The Lower Yakima Valley, Washington, Dallin Jensen Jan 2017

Isotope Investigation Of Nitrate In Soils And Agricultural Drain Waters Of The Lower Yakima Valley, Washington, Dallin Jensen

All Master's Theses

Nitrate in the groundwater of the Lower Yakima Valley, Washington has long been known to frequently exceed the EPA maximum contaminant level standard for potable water (10 mg/L), adversely impacting communities with disadvantaged socio-economic status. In this research, nitrogen and oxygen isotopic signatures were determined for nitrate soil leachates and irrigation return flow collected in the Lower Yakima Valley, Washington and compared to previous isotopic studies of nitrate in Central Washington. δ15N, δ18O and Δ17O values are used to constrain sources of to groundwater. Isotope signatures for nitrate from soil leachate largely overlapped with …


Geologic And Geochemical Characterization Of Cross-Communication Potential Within The Northern Edwards Aquifer System, Texas, Ingrid J. Eckhoff Dec 2016

Geologic And Geochemical Characterization Of Cross-Communication Potential Within The Northern Edwards Aquifer System, Texas, Ingrid J. Eckhoff

Electronic Theses and Dissertations

The Edwards Aquifer is a large, complex groundwater system located throughout Central Texas in association with the Balcones Fault Zone. The San Antonio and Barton Spring segments of the Edwards Aquifer have been extensively studied in the past because they provide groundwater resources to the largely urbanized areas of San Antonio and Austin, respectively, and smaller communities along the Interstate 35 corridor. Previous research has been conducted on these southern and central portions of the Edwards Aquifer system, which have characterized the structural, hydrogeological and geochemical variations within the highly karsted region. However, the Northern Segment of the Edwards Aquifer …


Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb Dec 2016

Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb

Graduate Theses and Dissertations

Dissolved concentrations of CO2 in a karst aquifer are a major control on calcite dissolutional processes, as CO2 combines chemically with water to form carbonic acid. As increasing amounts of CO2 are added to the system, greater resultant water aggressivity generates greater rates of dissolution. Spatial and temporal variations in carbon flux through the system may occur over a range of time scales, and high-resolution data collection is needed to truly understand and characterize such variability. Continuous CO2 monitoring in War Eagle Cavern, Arkansas, will suggest a number of influential parameters with varying degrees of importance throughout an annual cycle. …


Three-Dimensional Geologic Modeling And Groundwater Flow Modeling Above A Co2 Sequestration Test Site, Erin Carlock, Eric W. Peterson, David H. Malone Jul 2016

Three-Dimensional Geologic Modeling And Groundwater Flow Modeling Above A Co2 Sequestration Test Site, Erin Carlock, Eric W. Peterson, David H. Malone

Faculty Publications - Geography, Geology, and the Environment

As temperatures rise and climate change becomes an increasingly important issue, geologic carbon dioxide (CO2) sequestration is a viable solution for reducing greenhouse gas emissions. Subsurface 3-D modeling and groundwater flow modeling were completed as a component of a CO2 sequestration feasibility study in the city of Decatur, Illinois. The Decatur Archer Daniels Midland Company Ethanol Plant (ADM) serves as the injection site for a CO2 sequestration project within a deep saline reservoir. Petrel was successfully used to model the glacial deposits in the area. The 3-D geologic model shows the Peoria Silt, Wedron Formation, and Cahokia Formation at the …


Three-Dimensional Architecture And Hydrostratigraphy Of Cross-Cutting Buried Valleys Using Airborne Electromagnetics, Glaciated Central Lowlands, Nebraska, Usa, Jesse T. Korus Dr., Robert Matthew Joeckel, Dana P. Divine, Jared D. Abraham Jul 2016

Three-Dimensional Architecture And Hydrostratigraphy Of Cross-Cutting Buried Valleys Using Airborne Electromagnetics, Glaciated Central Lowlands, Nebraska, Usa, Jesse T. Korus Dr., Robert Matthew Joeckel, Dana P. Divine, Jared D. Abraham

Conservation and Survey Division: Faculty and Staff Publications

Buried valleys are characteristic features of glaciated landscapes, and their deposits host important aquifers worldwide. Understanding the stratigraphic architecture of these deposits is essential for protecting groundwater and interpreting sedimentary processes in subglacial and ice-marginal environments. The relationships between depositional architecture, topography and hydrostratigraphy in dissected, pre-Illinoian till sheets is poorly understood. Boreholes alone are inadequate to characterize the complex geology of buried valleys, but airborne electromagnetic surveys have proven useful for this purpose. A key question is whether the sedimentary architecture of buried valleys can be interpreted from airborne electromagnetic profiles. This study employs airborne electromagnetic resistivity profiles to …


Determining Groundwater Sources And Ages Via Isotope Geochemistry In Big Sky, Montana, Thomson Connie Jul 2016

Determining Groundwater Sources And Ages Via Isotope Geochemistry In Big Sky, Montana, Thomson Connie

Graduate Theses & Non-Theses

The Big Sky ski resort area in southwestern Montana is experiencing exponential growth in both development and population. Concerns have arisen over the quantity of good-quality groundwater in the region, and whether there is a large enough reserve to support the growing demand. In light of already-documented water-level decreases, and domestic wells needing to be deepened or replaced, the Montana Department of Natural Resources and Conservation (DNRC) enlisted the Montana Bureau of Mines and Geology's Ground Water Investigation Program to perform an assessment of groundwater availability and quality in the region, and define groundwater supply sources.

The geology in the …


Pumping Tests, La Grange Region, Western Australia, Groundwater Consulting Services Jul 2016

Pumping Tests, La Grange Region, Western Australia, Groundwater Consulting Services

Natural resources commissioned reports

Groundwater Consulting Services was contracted to collate and analyse pumping test information from four sites in the La Grange region, near Broome. Two of the pumping tests were conducted by Groundwater Consulting Services and two pumping tests were conducted by Kimberley Water Pty Ltd under instruction from the Department of Agriculture and Food, Western Australia.

The major objective of the work was to provide aquifer hydraulic data to be used as input into a numerical model being developed by the Department of Agriculture and Food. A secondary objective was to provide irrigation water supply development advice for potential irrigation projects. …


An Investigation Of Hydrogeologic, Stratigraphic, And Structural Controls On Acer Grandidentatum Communities In A Karst Landscape, Owl Mountain Province, Fort Hood Military Installation, Texas, Melinda S. Faulkner May 2016

An Investigation Of Hydrogeologic, Stratigraphic, And Structural Controls On Acer Grandidentatum Communities In A Karst Landscape, Owl Mountain Province, Fort Hood Military Installation, Texas, Melinda S. Faulkner

Electronic Theses and Dissertations

The Owl Mountain Province is located within the Fort Hood Military Installation, an approximately 880 km2 installation established in the 1940s in Bell and Coryell counties, Texas, which has undergone extensive land use changes associated with military training, maintaining much of the vegetation in early succession. This study investigates thelithologic, stratigraphic, and structural controls on the hydrologic, hydrogeologic, and geomorphologic evolution of the Owl Mountain Province as expressed by mesic vegetation communities, including Pleistocene relicts Acer grandidentatum, within karst terrains. These systems exhibit complexly overprinted speleogenetic evolutions within a dynamic groundwater regime resulting from regional climate shifts throughout the …


Speleogenesis Of Critchfield Bat Caves And Associated Hydrogeology Of The Northern Edwards Aquifer, Williamson County, Texas, Ashley N. Landers May 2016

Speleogenesis Of Critchfield Bat Caves And Associated Hydrogeology Of The Northern Edwards Aquifer, Williamson County, Texas, Ashley N. Landers

Electronic Theses and Dissertations

Karst development in the Edwards Aquifer has been significantly studied in the San Antonio and Barton Spring Segments; however, karst development remains poorly studied in the Northern Segment. Detailed characterization of the Northern Segment is vital for future water conservation because of increasing urban sprawl along the Interstate 35 corridor. The Northern Segment of the Edwards Aquifer consists of Lower Cretaceous strata of the Comanche Peak, Edwards, and Georgetown formations. The stratigraphy is dominated by Edwards Limestone as it is the only formation that crops out in the study area.

Karst, stratigraphic, GIS, and geochemical studies were conducted to evaluate …


Cockatoo Sands In The Victoria Highway And Carlton Hill Areas, East Kimberley: Hydrogeology, Aquifer Properties And Groundwater Chemistry, D L. Bennett, John Andrew Simons, Richard J. George Dr, Paul Raper May 2016

Cockatoo Sands In The Victoria Highway And Carlton Hill Areas, East Kimberley: Hydrogeology, Aquifer Properties And Groundwater Chemistry, D L. Bennett, John Andrew Simons, Richard J. George Dr, Paul Raper

Resource management technical reports

Cockatoo Sands are recognised as potentially suitable for irrigated agriculture because they are generally well drained and not subject to waterlogging or inundation. These characteristics allow them to be cultivated and prepared for planting various crops during the wet and dry seasons of northern Australia. Expanding agricultural production onto the Cockatoo Sands around Kununurra will increase opportunities for agriculture by increasing the overall scale of agriculture, allowing year-round agricultural enterprise, new crops and new market opportunities.

DAFWA has assessed the soil characteristics and agriculturally suitable areas of Cockatoo Sands in the Victoria Highway and Carlton Hill areas near Kununurra. Potential …


Modeling The Influence Of The Heterogeneous Substrate On The Transport Of The Jet Fuel Solute Plume, Kirtland Air Force Base, Albuquerque, New Mexico, Hannah Sarah Gatz-Miller May 2016

Modeling The Influence Of The Heterogeneous Substrate On The Transport Of The Jet Fuel Solute Plume, Kirtland Air Force Base, Albuquerque, New Mexico, Hannah Sarah Gatz-Miller

Earth and Planetary Sciences ETDs

A subsurface model was developed to characterize the influence of heterogeneity on solute phase plume migration of the Jet Fuel spill of Kirtland Air Force Base. Core –logs from KAFB boreholes were compiled, and lithology was interpolated across the study area using transition probability geostatistics (T-PROGS). High conductivity materials in the travel path resulted in a faster than average breakthrough time while, if low conductivity materials were placed in the travel path, particles were either forced to divert around the low K material, which added time and changed the direction of travel, or were forced by the hydraulic gradient to …


Hydrogeological Conceptual Model Of La Villa River Watershed, Republic Of Panama, Maria G. Castrellon Romero Apr 2016

Hydrogeological Conceptual Model Of La Villa River Watershed, Republic Of Panama, Maria G. Castrellon Romero

Honors Scholar Theses

Groundwater in Panama is a valuable and poorly understood resource. Its exploitation has increased 75% in the past decade, reaching a total value of 700,000 m3/day or 185 million gallons per day (MGD). Climate change has caused a lengthening of the dry season, which has reduced precipitation and streamflow, resulting in surface water scarcity during this period. Nevertheless, it has not been possible to determine the extent to which groundwater sources have been affected by these factors since systematic monitoring of groundwater levels has not been implemented in Panama. With support from National Institution of Drinking Water Supply …


Natural Acid Rock Drainage And Ferricrete Deposit Chemistry Of The Judith Mountains, Montana, Sara Edinberg Apr 2016

Natural Acid Rock Drainage And Ferricrete Deposit Chemistry Of The Judith Mountains, Montana, Sara Edinberg

Graduate Theses & Non-Theses

The Judith Mountains are a low-elevation “island” mountain range in east-central Montana composed of a series of laccoliths and stocks cut by coarse-grained alkali granite and tinguaite dikes. The geology of the Judith Mountains in the vicinity of Red Mountain and Judith Peak, two of the tallest mountains in the range, is conducive to the creation of headwater streams that are naturally acidic. Extensive limonite staining on Red Mountain attests to the widespread presence of disseminated pyrite in hydrothermally altered porphyry rock. However, no major historical mining operations are known to the area. The acidic streams undergo neutralization in pH …


Lnfluence Of Persulfate On Solidification/Stabilization Characteristics Of Iss Treatment, Jeffrey M. Hudson Apr 2016

Lnfluence Of Persulfate On Solidification/Stabilization Characteristics Of Iss Treatment, Jeffrey M. Hudson

Masters Theses

Two environmental remediation technologies that lend themselves well to being combined in a single application are In Situ Chemical Oxidation (ISCO) using activated persulfate (PS), and In Situ Stabilization (ISS). Persulfate can be activated by increasing the pH to 10.5 and/or increasing temperatures to 30ºC. Many common ISS amendments increase temperature to 30°C and/or pH to 10.5 when in contact with soil water. Laboratory experiments were conducted with various soils to determine the ability of eight ISS amendments to activate persulfate. All eight ISS amendments activated persulfate. This work also showed that the relative contribution of heat vs. alkaline activation …


High-Resolution Ground-Penetrating Radar Profiles Of Perennial Lake Ice In The Mcmurdo Dry Valleys, Antarctica: Horizon Attributes, Unconformities, And Subbottom, Hilary A. Dugan, Steven A. Arcone, Maciej K. Obryk, Peter T. Doran Jan 2016

High-Resolution Ground-Penetrating Radar Profiles Of Perennial Lake Ice In The Mcmurdo Dry Valleys, Antarctica: Horizon Attributes, Unconformities, And Subbottom, Hilary A. Dugan, Steven A. Arcone, Maciej K. Obryk, Peter T. Doran

Geology Faculty Publications and Presentations

Ground-penetrating radar (GPR) is not commonly used to study lake ice, and in general, the ground-based use of radar frequencies greater than 500 MHz in cryosphere geophysics is rare, due to a general interest in deeper stratigraphy and the difficulty of extensive profiling over rough snow surfaces. Our goal was to find further information on the origin of the deposition and formation of intra-ice layers, bottom topography, and subbottom deposits using GPR with pulses centered near 850 MHz on two permanently ice-covered lakes in the Mc- Murdo Dry Valleys, Antarctica. The profiles were obtained using a one-person sled operation over …