Earth Sciences Commons^™

Collisional Reactivation Of Rift Margin Fracture Zones, Taiwan And The Taconic Allochthon, David C. Mirakian

Master's Theses

Chapter I. Transverse Topographic Development due to the Reactivation of a Partially-Subducted Fracture Zone: The Southwest Hsüehshan Range, Central Taiwan

Abstract — The southwest flank of the Hsüehshan Range is defined by a topographic break which cuts across regionally mapped structures in central Taiwan. The mountain front trends ~345°, slightly oblique to the Sanyi-Puli seismic zone which has been previously interpreted as a reactivated continental margin fracture zone. Structural data collected along the length of the topographic break reveal two populations of cross-cutting faults with distinct fault-zone materials and a series of southwest-plunging folds. Paleostress axes were reconstructed using the …

Mineralogy And Geochemistry Of Anorogenic Granitic Miarolitic Pegmatites Associated With The White Mountain Intrusive Suite, New Hampshire, Kristen F. Camp

University of New Orleans Theses and Dissertations

Subvolcanically emplaced granitic, miarolitic pegmatites associated with the White Mountain Igneous Province (WMIP), New Hampshire, were sampled and analyzed using modern analytical techniques including X-ray fluorescence, electron microprobe, scanning electron microscopy, and direct-coupled plasma spectrophotometry. Analytical results suggest that all the sampled miarolitic pegmatites from this study are petrogenetically related to the same intrusive suite, the WMIP. Based on the geochemical data, all the samples formed in an anorogenic tectonic setting and are rift-related. They are classified as NYF-type and plot in the “within plate granite” field on tectonic discrimination diagrams. The majority of the samples are peraluminous, A_{1 …}

Understanding Uplift Of The Ethiopian Plateau From Longitudinal Profile Analysis Of The Blue Nile Drainage System, Prabhat Chandra Neupane

University of New Orleans Theses and Dissertations

The Ethiopian Plateau is one of the few tectonically-active regions on Earth that is situated in continental rift zones. About 1.6 km deep gorge of the Nile was carved by the Blue Nile River on the Ethiopian Plateau, as the plateau has been experiencing continuous uplift and exhumation in the Cenozoic. Here, we used quantitative analysis of longitudinal rive-profile forms and parameters (knickpoint and normalized steepness-index k_sn) of the Blue Nile tributaries to tease out regional tectonic signals.

244 knickpoints were examined in the tributaries, majority (>80%) of which are unassociated with lithology or geological structures. Knickpoint …

Exchange Flows In An Urban Water Body: Bayou St. John Responses To The Removal Of Flood Control Structures, Future Water Elevation Control, And Water Quality, Robin L. Schroeder

University of New Orleans Theses and Dissertations

Bayou St. John, an urban water body extending south from Lake Pontchartrain, has two anthropogenic structures that regulate flow from the Lake . The City of New Orleans has plans to remove the inner control structure to improve water quality. Field and numerical methods used in this study show removing this structure increased water elevations throughout the Bayou but resulted in lower water elevation signal amplitudes that caused a lower tidal flow exchange from north to south. Bulk Richardson numbers showed mixing was inversely related to flow and the Bayou generally remains stratified. Resuspension of contaminated sediment could negatively impact …

Thermal Plume Transport From Sand And Gravel Pits Potential Thermal Impacts On Cool-Water Streams, Jeffrey M. Markle

Electronic Thesis and Dissertation Repository

Potential thermal impacts from below-water-table aggregate extraction on a cool-water stream were investigated by monitoring thermal plumes, moving through an unconfined glacial-outwash aquifer, and assessing their subsurface persistence. The growing demand for aggregate and increased pressure to pursue extraction in ecologically sensitive areas has driven the need for this work. During a 10-year period, ground and surface water temperatures were measured monthly, including two periods of intensive monitoring (22 months and 2.5 years). The aquifer hydraulic conductivity (K) is quantified at the laboratory and field scale. The mean K’s from the multi-scale tests depend on test-support volume and …

An Integrated Geophysical And Geologic Study Of The Paleogene-Age Volcanic Body And Possible Landslide Deposit On The South Slope Of The Traverse Mountains, Utah, John C. Hoopes

Theses and Dissertations

Development of homes, roads, and commercial buildings in northern Utah has grown significantly during the last several decades. Construction has expanded from the valley floor to higher elevations of benches, foothills, and other elevated regions of the Wasatch Mountain Front. Construction in the higher elevation areas are a concern due to potential for landslides, both new and reactivated. Landslides have been identified in this region and are dated as Pleistocene to historical in age. A possible landslide of about 0.5 km2 on the south slope of Traverse Mountain has been mapped by the Utah Geological Survey in 2005. Its surface …

Quantification Of Glacier Melt Volume In The Indus River Watershed, Maria Nicole Asay

Theses and Dissertations

Quantifying the contribution of glaciers to water resources is particularly important in locations where glaciers may provide a large percentage of total river discharge. In some remote locations, direct field measurements of melt rates are difficult to acquire, so alternate approaches are needed. Positive degree-day modeling (PDD) of glacier melt is a valuable tool to making first order approximations of the volume of melt coming from glaciers. In this study, a PDD-melt model is applied to glaciers in the Indus River watershed located in Afghanistan, China, India, and Pakistan. Here, millions of people rely on the water from the Indus …

Whole-Rock Lead-Lead Systematics And Major Element Analyses On The 1.85 Ga. Flin Flon Paleosol, Manitoba, Canada: Implications For Uranium Mobility., Federico Arturo Valencia

Geosciences Theses

The 1.85 Ga Flin Flon paleosol located in Flin Flon, Manitoba, Canada, is studied with the purpose of determining the timing and geochemical trend of uranium migration. Radiometric minimum ages of sediments and paleosols indicates the presence of a post-depositional event, these ages are bracketed by the Trans-Hudson orogeny event (2155–1750 Ma) which resulted in the alteration of κ(Th/U) and µ(U/Pb) ratios by exposing volcanics to the atmosphere and instigating the mobilization of U. The profile shows that the Missi sediments lost Uby 84% average relative to corrected average upper crust value. The upper paleosol gained U by 11% and …

Dendroclimatology And Woodland Dynamics On The Volcanic Badlands Of Western New Mexico, U.S.A., Mark Daniel Spond

Doctoral Dissertations

My dissertation research addressed woodland dynamics and dendroclimatology on the volcanic badlands of western New Mexico. The research was intended to complement previous studies by: (1) assessing vegetation structure and composition dynamics at El Malpais National Monument between 1948–2010 using repeat photography; (2) improving knowledge of the influence of climate and land use on vegetation dynamics at El Malpais National Monument; (3) providing a unique tree-ring data set from Rocky Mountain juniper growing on the malpais; (4) elucidating relationships between Pacific teleconnections and radial growth in Rocky Mountain juniper; and (5) improving understanding of the dynamic nature of climate in …

Experimental Investigations Of Fluid–Mineral Interactions In Olivine And Dolomite, Michael Thomas Deangelis

Doctoral Dissertations

Geochemical processes involving the interaction of fluids and minerals occur in nearly every environment on the surface and in the crust of the Earth. The variety of fluid–mineral processes on the Earth is quite diverse, and these various processes can occur under a large range of geochemical conditions. Aqueous dissolution and alteration, hydration, protonation, solution–precipitation, diffusion, and fluid and isotope exchange are among the many fluid–mineral interaction processes that contribute to the overall cycling of elements on Earth. This dissertation uses analog experiments to examine fluid­–mineral interaction processes found in different geological environments and under a range of environmental conditions. …

Environmental Impact Of The Three Kids Mine Tailings, Henderson, Nv, Ji Hye Park

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research focused on the distribution of the Three Kids Mine tailings in surface soils in and around the mine in Henderson, Nevada. It is situated next to the communities of Calico Ridge and Lake Las Vegas Resort, and, just the west of the Lake Mead Recreation area. Even though the mine has been inactive for almost 50 years (1917-1961), tailing piles and other sources of contamination on the mine are currently exposed to the atmosphere. In this study, surface soil samples were collected along eight transects emanating from the center of Three Kids Mine tailing piles up to five …

Temporal And Spatial Analysis Of Stream And Groundwater Interactions, Ryan Eugene Warden

Boise State University Theses and Dissertations

Water chemistry and ecology of streams are impacted by the amount of water that exchanges between the surface water system and the adjacent saturated area, called the hyporheic zone, a dynamic area of stream channel sediments, which undergoes down-welling or up-welling of stream water. The rate and volume of water exchange between the surface water and the hyporheic zone are primary controls on stream ecology, but are challenging to assess. A common approach is to model the exchange rate with a one-dimensional advection-dispersion equation that includes solute exchange with transient storage zones, which is referred to as a transient storage …

Late Pleistocene And Holocene Hydroclimate Change In The Southeastern United States: Sedimentary, Pedogenic, And Stable Carbon Isotope Evidence In Tennessee River Floodplain Paleosols, James Joseph Kocis

Masters Theses

In order to understand hydroclimate variability of future climate change, it is important to know the timing and range of natural climate change in the past. The Southeastern United States (SE) is situated along the poleward extent of projected subtropical drying, where the expression of past hydrological balances remains unclear. The lack of high-resolution paleohydroclimate records in the SE forces climate modelers to base interpretations on better-understood regions of North America. The SE likely experienced significant changes in precipitation regimes resulting from its position at the convergence of several oceanic and continental air masses. To reconstruct precipitation variability, this study …

Field-Based Constraints On The Origin Of The Benton Uplift, Ouachita Mountains, Rachel Victoria Keng

Graduate Theses and Dissertations

The Ouachita Mountains are an east-west trending fold-and-thrust belt exposed in west central Arkansas and southeastern Oklahoma. The Mississippian-Pennsylvanian Ouachita orogeny occurred when the Sabine arc terrane collided during south-facing subduction, during closure of the Cambrian passive margin of the North American plate. Deep-water Paleozoic strata were incorporated into an accretionary wedge as the Sabine terrane approached the North American plate. Folds and thrust faults in the Ouachita Mountains generally verge north due to tectonic transport of an accretionary wedge from south to north. Structures in the Benton and Broken Bow Uplifts (located in the core of the wedge) locally …

Age, Stratigraphy And Depositional Environment Of The Pliocene Copper Canyon Formation, Death Valley, California, Torrey Nyborg

Loma Linda University Electronic Theses, Dissertations & Projects

The Copper Canyon Formation, a fluvial-lacustrine deposit exposed within the Black Mountains of Death Valley National Park, has only previously been broadly included in regional tectonic and depositional analyses. The formation is significant because it preserves numerous shoreline-playa features including highly abundant and diverse mammal and bird tracks. The formation represents a basin fill sequence consisting of approximately 1800 m of conglomerates, basalt flows, and lacustrine deposits. A measured type section along with x-ray diffraction, isotopic analysis, and thin section petrography shows an evolution of the ancient Copper Canyon lake from an hypersaline evaporative lake to a perennial saline lake …

Nitrogen Retention And Denitrification In Reservoirs, Erin Grantz

Graduate Theses and Dissertations

Studies coupling direct measurements of micro-scale nitrogen (N) cycle processes with ecosystem-scale flux estimates are needed to determine N retention hotspots within river networks, where up to 50% of terrestrial loading to aquatic systems is retained. This study examined the role of denitrification, a microbially-mediated reactive N removal pathway, in ecosystem-scale N retention in 3 small (< 1 km2), shallow flood-control reservoirs. Annual reservoir N retention was estimated through mass balance modeling of system inputs and outputs. Annual denitrification rates were estimated by combining multiple measurements of seasonal, habitat-specific dinitrogen gas (N2) fluxes. Annual reservoir N retention ranged from 14 - 19 g m-2 in the reservoirs, while reactive N removal through denitrification was 13 - 25 g m-2. Denitrification efficiency, or the portion of the retained N load that was denitrified, was high relative to other lentic systems and was > 100% at 2 sites. Previous lentic denitrification studies may have underestimated denitrification efficiency by not considering water column denitrification, which was 50% of total denitrification at one study reservoir. However, not all potential inputs, most importantly biological N2 fixation, were included in this …

Relating Land Cover And Channel Morphology To Stream Flow Function In The Lower Pee Dee Watershed, South Carolina, Zachary Smoot

All Theses

The South Carolina Pee Dee Project (SCPDP) aims to develop a method for the determination of Minimum Allowable Flows (MAFs) in streams in the Pee Dee region. This study is a portion of the larger SCPDP, focusing primarily upon analyses of geomorphic and hydrologic processes, as well as landscape and habitat analyses. Specific objectives include: 1) To distinguish the effect of various land cover classes and scales of analyses on components of stream flow function; 2) To determine trends in hydraulic geometry (regional curves) for the SCPDP region; and 3) To determine what measures of stream flow function, stream geomorphology, …

The Interrelationship Between The Bio- And Sequence Stratigraphy Of The Middle Cambrian Spence Shale Of Northern Utah And Southern Idaho, Eva Lyon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was undertaken with the objective of discerning the relationship between sea level change and changes in the fauna of the Spence Shale. A combination of field and lab work was employed to undertake this research. The Spence Shale is rich in fossils from the earliest period of visible life on this planet. It provides a unique window onto the evolution of life and changes in the Earth at this time. It is important to study this relationship between sea level and life changes as these conditions are constantly changing, particularly in this day and age. A better understanding …

Determining Co2 Storage Potential: Characterization Of Seal Integrity And Reservoir Failure In Exposed Analogs, Daniel Corey Barton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sequestration of carbon dioxide (CO₂) into subsurface porous sandstone is proposed as a method for reducing accumulation of anthropogenic emissions of CO₂ into the atmosphere. Natural exposures of reservoir and top-seal pairs in central and southeastern Utah are identified as analogs to proposed CO₂ injection targets. Reservoir and top-seal pairs in natural analog exposures are analyzed in tandem to evaluate evidence for paleo-migration of fluids and/or hydrocarbons from the reservoir through the top seal. The San Rafael Swell and Monument Uplift exhibit similar structure and exposures of Jurassic units yet differ in amount and type of …

Aeolian Simulations: A Comparison Of Numerical And Experimental Results, With Projections For Titan., Oscar Lee Mathews

Masters Theses

Aeolian processes are major determinants of geomorphology on bodies in the Solar System possessing an atmosphere-surface interface and transportable sediment, including Earth, Mars, Venus, and Titan. Substantial efforts have been made over the last few decades to understand these processes using specialized wind tunnels, field studies, and, more recently, numerical simulations. This thesis describes a model of aeolian sediment transport using computational fluid dynamics (CFD), and compares the results with those obtained in the Martian Surface Wind Tunnel (MARSWIT) testing conducted in the Planetary Aeolian Laboratory at NASA Ames Research Center. The ultimate goal of the thesis was to develop …

Effect Of Landscape Position And Dairy Manure Addition On Bioavailable Forms Of Soil Phosphorus Using Enzyme Hydrolysis, Themis Mahalia Stone

Masters Theses

Bioavailable phosphorus (P) has traditionally been measured as inorganic orthophosphate (PO₄) while organic P (P_o) has been considered of limited relevance to short-term biological consumption. However, enzymes secreted by bacteria and fungi which serve to mineralize P_o are ubiquitous in the environment and may contribute significant bioavailable P over time. In order to assess environmentally-relevant, potentially bioavailable P in soils with added dairy wastes, microcosms of identical soil series but differing management histories and landscape positions were incubated at 24 C° for three weeks. Subsamples were taken weekly from microcosms and analyzed by: 1) Mehlich-3 …

Processes Controlling The Composition Of First-Cycle Sediments Deposited In An Arid-Climate, With Implications For Provenance Reconstruction Studies, Aubrey Lynn Modi

Masters Theses

Petrologic analysis of first-cycle clastic sediments derived from a single source in an arid environment provides a means to determine how well they resemble the petrology and geochemistry of their source. The Stepladder Mountains, located in the Mojave Desert of southeastern California, represents a well-controlled location (i.e., arid environment; single, known source; short transport distance) to examine how naturally formed sediments acquire their compositions. Compositional modifications associated with sediment production were resolved through direct examination of the weathered components (regolith, grus, and sediments). Sediment compositions strongly vary by grain size, indicating that, after the source itself, hydrodynamic sorting played the …

Improvements In Multi-Tool Surveying Efficiency For Archaeological Geophysics, Caitlyn Marie Williams

Masters Theses

Conventional archaeological excavation methods are, by nature, extremely invasive and result in study areas being irrevocably altered for the sake of research. For this reason, near-surface geophysical techniques have been incorporated into archaeological investigations to aid in determining the locations of buried features with minimal damage to the site. The objective of this research was to perform a geophysical survey at an archaeological site on the Akrotiri Peninsula in Cyprus to locate evidence of a Roman naval base and to develop an improved data management workflow that will improve the usefulness of geophysical data to archaeologists.

An on-site archaeologist determined …

Microstructural Characterization Of Kinked Germanate Olivine Grains, Alex Gregory Drue

UNLV Theses, Dissertations, Professional Papers, and Capstones

Olivine is the most common and the weakest mineral in the upper mantle. Thus the strength of olivine controls the rheology of the earth's upper mantle. The rheology of olivine in the upper mantle has important implications for mantle flow, mountain building, and rates of isostatic adjustment. Recent experimental measurements of the flow strength of deformed olivine polycrystals have assumed a homogeneous state of stress. X-ray synchrotron diffraction experiments have implied that this assumption is not always valid. Elastic Plastic Self Consistent (EPSC) modeling offers an approach to estimating the flow strength of olivine that does not assume a homogeneous …

Effects Of High-Impedance-Contrast Boundary Upon Multi-Modal Seismic Surface Wave Data, Prajwol Tamrakar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Synthetic studies and analyses of an experimental dataset were conducted to address the use of Rayleigh-type surface waves for estimation of shear wave velocity (VS) profiles of shallow bedrock sites. The shallow bedrock presents a high impedance contrast boundary which causes surface wave energy to be partitioned to higher modes. Idealized studies of hypothetical datasets and root-mean-squared calculations of error surfaces showed that if reliable dispersion data are available over a broad frequency spectrum, the VS profile can be recovered using the fundamental mode alone. However, when dispersion data are limited to a relatively narrow frequency band representing what might …

Paired Positive Carbonate Carbon Isotope, Organic Carbon Isotope, And Oxygen Isotope Composition Study Across The Lower Mississippian Positive Carbon Isotope Excursion, Southeastern Nevada, Usa, Robert Alan Henry

UNLV Theses, Dissertations, Professional Papers, and Capstones

A prominent positive carbonate carbon isotope (delta13Ccarb) excursion of Early Mississippian age (ca 351 Ma) has been documented by previous studies from numerous sites globally. This delta13Ccarb excursion has been interpreted as resulting from enhanced organic carbon burial that removed 13C-depleted carbon from the ocean and atmosphere. Anticipated outcomes from enhanced organic carbon burial would include a similar positive excursion in organic carbon isotopes (delta13Corg) and a global cooling event resulting from reduced CO2 in the atmosphere and ocean. These predictions, however, were not tested sufficiently in previous studies. This research has tested these predictions through an integrated study of …

Magma Chamber Processes At Mutnovsky Volcano, Russia, Kelly L. Robertson

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is composed of two manuscripts about the evolution of Mutnovsky Volcano in Kamchatka, Russia. Mutnovsky has been active for the past approximately 80,000 years, during which there was the formation and subsequent eruption of four major stratocones. These four eruptive centers, named Mutnovsky I, II, III, and IV from oldest to youngest, have a range of erupted product compositions from basalt to dacite. The first major goal of this project was to investigate the melt source for Mutnovsky. Whole rock trace element and Nd, Sr, and Pb isotopic data were used to determine that the melt source was …

Using Geographical Information Systems To Investigate Spatial Patterns In Fossils Of Tapirus Polkenis From The Gray Fossil Site, Washington County, Tennessee, Winn Addison Ketchum

Electronic Theses and Dissertations

Discovered in 2000, the Gray Fossil Site provides a snapshot of the flora and fauna that lived during late Miocene to early Pliocene time in eastern Tennessee. These fossils occur in sediments consisting of fine-grained clays and sands of lacustrine origin, which were deposited after multiple sinkholes formed in the underlying Knox Group basement carbonates. Three-dimensional nearest neighbor analysis has been applied to fossils of Tapirus polkensis, characterizing the spatial patterns exhibited. These analyses determined the importance of taphonomic and depositional processes that occurred during the sites formation. Six characteristics were analyzed, four at the bone level including carnivore …

Structural And Stratigraphic Relationships Near The Southern Terminus Of The Pulaski Fault, Northeast Tennessee, Phillip Michael Derryberry

Masters Theses

The Pulaski fault is one of the master thrust faults in the Appalachian Alleghanian fold-thrust belt. Detailed geologic mapping of Cambrian and Ordovician strata in northeastern Tennessee revealed key structural and stratigraphic characteristics for distinguishing the Pulaski thrust sheet from its footwall, the Saltville thrust sheet. Unlike most thrust systems in the Valley and Ridge, the Pulaski records at least two deformation phases. Geometric and crosscutting relationships along parts of the Pulaski thrust sheet in this study area and in southwestern Virginia suggest hanging wall and possibly some footwall deformation prior to the emplacement of the thrust sheet. The initial …

Spatial And Temporal Variations In The Air-Sea Carbon Dioxide Fluxes Of Florida Bay, Christopher Michael Dufore

USF Tampa Graduate Theses and Dissertations

The flux of CO2 between the ocean and the atmosphere is an important measure in determining local, global, and regional, as well as short term and long term carbon budgets. In this study, air-sea CO2 fluxes measured using a floating chamber were used to examine the spatial and temporal variability of CO2 fluxes in Florida Bay. Measurements of dissolved inorganic carbon and total alkalinity obtained concurrently with chamber measurements of CO2 flux allowed calculation of ΔpCO2 from flux measurements obtained at zero wind velocity. Floating chamber measurements of ΔpCO2 were subsequently coupled with wind speed data to provide a simple …