Earth Sciences Commons^™

Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly

Masters Theses

Uranium processing and waste storage in unlined waste ponds leached contaminants into the groundwater at Y-12, Oak Ridge, Tennessee, from the 1950s to 1980s. Groundwater wells near the S-3 ponds have had the highest nitrate concentrations of groundwater anywhere in the world (>10,000 mg/L). For reference, the maximum contaminant level for nitrate in drinking water set by the U.S. Environmental Protection Agency is 10 mg/L. Since 2012, the ENIGMA (Ecosystems and Networks Integrated with Genes and Molecular Assemblies) group has been characterizing, monitoring, and conducting field experiments to understand the interactions between contaminants, microbes, and the subsurface. The goals …

The Importance Of Lithologic Variability And Stratigraphic Architecture In The Development Of Eogenetic Karst Systems, Nicholas J. Soto-Kerans

USF Tampa Graduate Theses and Dissertations

Integrative characterizations of karst systems on low-lying eogenetic carbonate platforms are rare and often limited to areas of direct observation where caves can be entered and explored. Because hydraulic properties of eogenetic limestones have been implicitly assumed to be homogeneous, classical models of carbonate island karst development stressed the importance of geochemical interfaces in controlling cave and vug development. These studies have explained the largest cavern systems as results of either 1) mixing dissolution at platform margins or 2) microbially-mediated dissolution processes at water tables.

New data from core descriptions and wireline logs obtained in 18 boreholes drilled in the …

Numerical Modeling Of Controlling Factors For Formation Of Unconformity-Related Uranium Deposits In Sedimentary Basins, Jiayue Shen

Electronic Theses and Dissertations

Unconformity-related uranium (URU) deposits are the most profitable uranium deposits in the world. Among those deposits, the Athabasca Basin hosts the world’s largest high-grade uranium deposits. A series of numerical experiments regarding the effect of uranium source location, fault location, and fault dip angle on the formation of URU deposits have been conducted by using software TOUHREACT.

Simulation results suggest that although both sandstone-sourced and basement-sourced models can generate economical deposits, basement-sourced models are more likely to form larger deposits since uranium-carrying fluid only needs to move a shorter distance to reach the structural trap for further ore forming reaction. …

Geologic Characterization Of The Nonconformity Interface Using Outcrop And Drillcore Analogs: Implications For Injection-Induced Seismicity, Kayla Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Starting around 2009, a greater number of earthquakes than anticipated have occurred in the midcontinent region of the United States. These earthquakes have been linked to increased rates and volumes of wastewater injection at several km’s depth into the Earth’s crust near a contact between crystalline metamorphic or igneous rock and overlying sedimentary rock, known as a nonconformity. While much is known about why these new earthquakes occur, comparatively little is known about the physical and chemical rock properties because the nonconformity contact is primarily buried under km’s of sedimentary rock in the midcontinent region. These rock properties are important …

Using Low-Flow Sampling Data To Estimate Hydraulic Conductivity In Aquifers, Joy Kiefer

Masters Theses

Hydrogeologists sample wells to test aquifer water quality and use slug tests to estimate aquifer permeability. Robbins et al. (2009) proposed a more efficient way to obtain the goals of the two tests—the use of low-flow sampling and the use of the resulting flow rate and drawdown data to estimate aquifer hydraulic conductivity (K). The Robbins et al. method calculates K by using the slope of the best fit line from the graph of flow rate vs. drawdown for all low-flow pumping data collected at a well. When the method was applied to low-flow data from four Kalamazoo, MI, it …

Spatiotemporal Patterns In Water Yield From The Humid Puna: A Case Study In The Agrarian District Of Zurite, Perú, Wyeth Wunderlich

Cal Poly Humboldt theses and projects

The humid puna is a seasonally dry alpine grass- and shrub-land biome that exists at the altitudinal limits of plant survival, hosts peat-forming wetlands known as bofedales, and yields water to streams used by small and large communities throughout the central and southern Peruvian Andes. Despite the importance of the humid puna in supplying water resources, particularly to perennial streams, few studies have quantified water yield and no studies have explored relationships between the structure of puna landscapes and spatial patterns in water yield. Zurite (population: 3,640, elevation: 3,011 m.a.s.l., annual precipitation: 855 mm) is an agrarian district in …

Relating Streamflow Discharge To Surface Elastic Response Under Hydrologic Loading Using Single Gps Vertical Displacement And The Storage-Discharge Relationship At Local Watershed Scales, Noah B. Clayton

Graduate Student Theses, Dissertations, & Professional Papers

Uncertainties associated with climate change and increasing demands for water resources require better methods for estimating water availability at small to intermediate watershed scales (<1500 km²). Temporal changes in watershed storage and transport across various watersheds in the western U.S. were investigated using the hydrologic loading signal from GPS vertical displacements as a proxy for changes in watershed total terrestrial storage. GPS vertical displacement and streamflow discharge relationships were analyzed at daily to monthly temporal resolution. Stream connected storage changes were inferred using discharge using a first-order dynamical system model. Storage inferred from discharge, GPS vertical displacement and storage …