Geology Commons^™

Cave Deposits And Sedimentary Processes In Cova Des Pas De Vallgornera (Mallorca, Western Mediterranean), Joan J. Fornós, Joaquin Ginés, Francesc Gràcia, Antoni Merino Juncadella, Lluís Gómez-Pujol, Pere Bover

International Journal of Speleology

The Cova des Pas de Vallgornera is an important and protected coastal cave, located in the southern part of the island of Mallorca, that outstands due to its length and the complex processes involved in its speleogenesis. Although sediments are not the main topic of interest, their presence as well as their paleontological contents are valuable evidence for paleoclimatic and chronological reconstructions of the cave morphogenesis. The sedimentary infilling is characterized by a scarce presence of clastic sedimentation, mainly composed of silts and clays, which can only be found at some minor passages in the innermost parts of the cave. …

Natural Radioactivity In Groundwater, Rocks And Sediments From Some Areas In The Uae: Distribution, Sources And Environmental Impact, Dalal Matar Al Shamsi

Dissertations

Groundwater contains a certain amount of natural radioactivity that generally results from the decay of uranium, thorium and ⁴⁰K isotopes. Knowledge of concentration levels, spatial distribution and sources of these isotopes in groundwater is crucial for environmentally safe and sustainable groundwater resources in the United Arab Emirates (UAE). This dissertation focuses on investigating the distribution, environmental impact and sources of ²³⁵U, ²³⁸U, ²³²Th, as well as the activity of gross β and α in groundwater in some locations in the UAE. Additionally, groundwater samples from Oman and selected aquifer rocks and sediments from the UAE were …

Modern To Late Pleistocene Stable Isotope Climatology Of Alaska, Alison Sloat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Understanding modern controls on climate is necessary to interpret past climatic conditions. This project investigated the modern controls on δ18O and δD values in Alaskan surface waters to interpret the controls on Late Pleistocene climate variability. ArcGIS was used to develop an isoscape of modern δ18O and δD values of over 400 surface water samples collected across Alaska and the Yukon. It was found that winter temperature and precipitation have the greatest controls on δ18O and δD values in Alaska, resulting in high δ18O values along the coast of the Gulf of Alaska and low values inland toward Central Alaska. …

Porosity Development Within Lobes To Downslope Ramp Deposits On A Prograding Carbonate Shelf Of The Kinderhookian To Osagean Series In Northwest Arkansas, Elizabeth Marchese

Graduate Theses and Dissertations

Carbonate bodies with lobate geometries form a substantial part of the Osagean (early Mississippian) section in northwest Arkansas. The purpose of this study is to isolate and describe a single lobe from three-dimensional exposures in quarry walls to provide criteria by which lobe and lobe porosity can be recognized in the subsurface. Carbonate sediment generated on the Mississippian Burlington shelf moved southward by gravity flows from the shelf margin to positions on a prograding ramp in Arkansas where overlapping deposits with lobate geometries accumulated. These deposits are recognized in outcrops of the Boone Formation. Stratigraphic units within the Boone are …

Application Of Detrital Zircon Geochronology To Determine The Sedimentary Provenance Of The Middle Bloyd Sandstone, Arkoma Shelf, Northern Arkansas, Greg Michael Buratowski

Graduate Theses and Dissertations

The sedimentary provenance of the middle Bloyd sandstone and subsequent sediment transport and dispersal patterns of the Early Pennsylvanian were interpreted by utilizing U-Pb detrital zircon geochronology. Eight middle Bloyd sandstone samples were analyzed. A total of 855 concordant analyses resulted. Peaks occurred at 350-500 Ma, 950-1200 Ma, 1300-1500 Ma, 1800-2300 Ma, and >2500 Ma. These peaks were determined to represent crystalline source rocks on the Laurentian craton from Acadian-Taconic, Grenville, Midcontinent Granite-Rhyolite, Yavapai-Mazatzal, Paleoproterozoic, and Archean Superior Provinces respectively. Grenville age zircons were the most common zircons identified in the middle Bloyd sandstone samples. The Appalachian Mountain region is …

3d Seismic Mapping Of Probable Tripolitic Chert Bodies In Osage County, Oklahoma, Richard Craddock Benson

Graduate Theses and Dissertations

The Mississippi Lime play is an important recent oil and gas development in the mid-continent of the United States. In April of 2007, Chesapeake Energy Corporation used horizontal drilling and tracing to bring the Howell 1-33H well online. This well revitalized the Mississippi Lime play, expanding exploration with potential Mississippian reservoirs.

The Mississippian section is a complex carbonate reservoir containing several distinct lithologies. An important Mississippian lithology known from outcrops in Arkansas and Missouri is tripolitic chert, or tripolite; a bleach, highly diagenetically altered, silica rock with high porosity, low density, and high permeability. Tripolite is an important reservoir target …

Rock Strength Of Caprock Seal Lithologies: Evidence For Past Seal Failure, Migration Of Fluids And The Analysis Of The Reservoir Seal Interface In Outcrop And The Subsurface, Elizabeth Sandra Petrie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Scientists have proposed that in order to avoid damaging climate change further accumulations of anthropogenic atmospheric carbon dioxide (CO₂) must be limited. One of several proposed techniques for reducing the amount CO₂ reaching the atmosphere is carbon capture and storage (CCS). This emerging technology stores CO₂ Emissions captured from large point sources (i.e. power plants or industrial facilities), in deep geologic formations, including depleted hydrocarbon reservoirs and saline aquifers. For successful CCS design, implementation and appropriate site selection and subsurface trapping mechanisms must be ensured over the 100's to 1000's of year timescale.

A key component …

Fault And Fluid Interactions In The Elsinore Fault-West Salton Detachment Fault Damage Zones, Agua Caliente County Park, California, Rebekah Erin Wood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study area provides a unique opportunity to study the intersection of the Elsinore and West Salton detachment faults in southern California, effusing warm springs, and alteration products in the midst of the fault intersection. Structural mapping and compiling previous maps supply an interpretation of the fault zone geometries within the Tierra Blanca Mountains. Geochemical analysis of the crystalline basement and altered protolith help determine the effects of faulting and fluid flow in the study area. In the Tierra Blanca Mountains, the Elsinore strike-slip fault system transitions from the double-stranded Julian segment and Earthquake Valley fault in the northwest, to …

The Effect Of Single Crystal Elastic And Plastic Anisotropy On Stress And Strain Heterogeneity: Comparison Of Olivine To Other Common Minerals, Christopher Joseph Cline Ii

UNLV Theses, Dissertations, Professional Papers, and Capstones

In order to investigate the influence of single crystal elastic anisotropy on the heterogeneity of stress distributions during polycrystalline deformation multiple deformed crystalline materials were analyzed using electron backscatter diffraction (EBSD). Deformation experiments were conducted on samples of Solnhofen limestone using a modified Griggs piston cylinder apparatus at UNLV, and also on San Carlos olivine using the D-DIA multi-anvil press at the National Synchrotron Light Source beamline X17B2. Analysis of the mechanical twins in deformed calcite and kink bands in olivine help elucidate deviations in local stress directions away from that of the applied macroscopic stress. Combined calculated compression directions …

The Application Of Zircon (U-Th)/He Thermochronology To Determine The Timing And Slip Rate On The Willard Thrust, Sevier Fold And Thrust Belt, Northern Utah, Bryan Eleogram

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although the Sevier fold-thrust belt is one of the best-studied foreland systems in the world, timing of motion on the dominant western thrust sheets that carry thick Neoproterozoic to Paleozoic strata remains incompletely understood. Zircon (U-Th)/He thermochrometry (ZHe) studies of the hanging wall of the Willard thrust sheet (WTS) in northern Utah are used to constrain the timing and rate of thrust slip. Previous interpretations of the age of initial slip on the Willard thrust vary widely from 150 to 115 Ma, reflecting ambiguous relations with foreland basin strata and limited geochronologic data. The large displacement on the Willard thrust …

Ore Characterization Of The Estelle Property In The South-~Central Alaska Range, Ember Flagg

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Estelle Property, located 170 km northwest of Anchorage, Alaska in the South Central Alaska Range, has been the focus of recent exploration activity for gold. Geological and geochemical investigations indicate that gold is spatially associated with felsic end-members of a series of zoned, Late Cretaceous intrusions that were emplaced into the Kahiltna terrane. A detailed study of outcrop and drill core samples was conducted to characterize host rock lithologies, intrusion compositions, and four main vein types including their mineralogy as well as their associated alteration mineral assemblages that are restricted to narrow selvages adjacent to veins. This study was …

Garnet Dating, Pressure-Temperature Time Paths And Kinematic Analysis Of The Schist Of Upper Narrows, Raft River Mountains, Northwestern Utah: Tectonic Implications Of Pressure-Temperature-Time-Deformation Paths, Alison Christine Lacy

UNLV Theses, Dissertations, Professional Papers, and Capstones

The hinterland of the Sevier orogenic belt underwent multiple episodes of synconvergent extension, prior to a brief transitional phase from shortening to overall extension that affected the entire orogen during the Early Eocene. The timing of the final transition from contraction to extension, while well documented in the Sevier fold-thrust belt, remains poorly constrained within the hinterland. The study of metamorphic rocks within the hinterland region provides a unique perspective on the nature of deformational events as well as the timing of the transition from contractional to extensional processes. Garnets from the schist of Upper Narrows in the western Raft …

The Kimama Core: A 6.4 Ma Record Of Volcanism, Sedimentation, And Magma Petrogenesis On The Axial Volcanic High, Snake River Plain, Id, Katherine Elizabeth Potter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Snake River Plain (SRP) is one of the best-preserved examples of continental hotspot volcanis, with a continuous record of volcanism that extends over 16 Ma to the present. Yellowstone-Snake River Plain records the migration of plume-tail volcanism from inception at the Bruneau-Jarbridge caldera complex at 12.6 Ma to its present locus, under the Yellowstone Plateau.

Records kept by the Snake River Plain volcanic actions include rhyolite lavas and ignimbritesm minor coeval basalts, and an overlying veneer of younger basalts. The central SRP has received comparatively little attention in the past. The Kimama core hole was drilled as part of …

Landscape Evolution Of The Needles Fault Zone, Utah, Investigated Through Chronostratigraphic And Terrain Analyses, Faye L. Geiger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Arcing eastward from the deep gorge of Cataract Canyon on the Colorado River is a series of aligned valleys (graben) and ridges (horst). This unusual landscape has formed as subsurface salt deforms toward the river and dissolves away, causing the overlying rocks to fault, slide, and subside. Geologists have long been interested in this actively evolving area they call the Needles fault zone, because understanding its mechanics and origin may shed light on how faults work in general and similar, yet inaccessible places like offshore rift zones or even the surface of the Moon. Despite this interest, the timing and …

The First 40ar/39ar Ages And Tephrochronologic Framework For The Jurassic Entrada Sandstone In Central Utah, Toby S. Dossett

Theses and Dissertations

The first 40Ar/39Ar ages of the Middle Jurassic Entrada Sandstone were derived from tephra beds found in central Utah. Eight air fall ash beds in the Entrada Sandstone, with 40Ar/39Ar biotite ages ranging from 168.1 ± 0.2 to 160.8 ± 0.2 Ma, help to establish the age of Entrada deposition. They were also used to create the first chronostratigraphic divisions within the mudstone-dominated Entrada Sandstone. Statistical cluster analysis of chemical data from electron microprobe analyses of phenocrysts were used as a second line of evidence to test absolute age and stratigraphic correlations. The first direct correlations of two distinct air …

Mesoscale Deformational Features Near Outcrop Analogs Of A Reservoir-Seal Interface: Implications For Seal Failure, Santiago L. Flores

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The boundary that separates reservoir rocks from caprock seals is generally considered a flow barrier for reservoir fluids. Buoyant fluids do no flow through the caprocks because they have low permeability and molecular forces at the base of the caprock resist upward flow. Deformation at the reservoir/caprock boundary may include fractures that increase permeability and lessen the effect of the molecular forces.

The injection and storage of carbon dioxide (CO₂) in porous sandstone with effective top seals below earth’s surface is a possible solution for reducing the amount of human-created CO₂ in the atmosphere. Uplift and erosion …

Geol 112: Hazards, Risks Of Earthquakes And Volcanoes Textbook Alternatives, Donald Reed

Textbook Alternatives Project Posters 2014

Poster summarizing cost saving textbook alternatives for GEOL 112: Hazards, Risks of Earthquakes and Volcanoes.

Quakemap, Richard Braxton

Collection of Engaged Learning

QuakeMap is a web application created with Javascript that allows users to track and view earthquakes in real-time. By using a system of linear scales, the application allows for quantitative data to be viewed qualitatively, and for information to be gathered at a glance.

Response Of Benthic Foraminifera To Ocean Acidification And Impact On Florida's Carbonate Sediment Production, Paul O. Knorr

USF Tampa Graduate Theses and Dissertations

Increasing concentrations of atmospheric CO2 are in dynamic equilibrium with the oceans. The absorption of CO2 by seawater causes a decrease in seawater pH and calcite saturation state (SS). This process, termed ocean acidification, exerts deleterious effects on marine calcifiers. Studies of symbiont-bearing large benthic foraminifera (LBF) have reported a generally unfavorable response to increased concentrations of carbon dioxide ([CO2]).

Experiments and analyses were undertaken to examine the effect of increased [CO2] on the growth rate, ultrastructure, stable isotopes of carbon and oxygen, as well as Mg/Ca of the high-Mg miliolid Archaias angulatus and the low-Mg rotalid Amphistegina gibbosa. A …

Climate And Topographic Controls On Simulated Pasture Production In A Semiarid Mediterranean Watershed With Scattered Tree Cover, J. Lozano-Parra, Marco P. Maneta, S. Schnabel

Geosciences Faculty Publications

Natural grasses in semiarid rangelands constitute an effective protection against soil erosion and degradation, are a source of natural food for livestock and play a critical role in the hydrologic cycle by contributing to the uptake and transpiration of water. However, natural pastures are threatened by land abandonment and the consequent encroachment of shrubs and trees as well as by changing climatic conditions. In spite of their ecological and economic importance, the spatiotemporal variations of pasture production at the decadal–century scales over whole watersheds are poorly known.We used a physically based, spatially distributed ecohydrologic model applied to a 99.5 ha …