Geology Commons^™

High-Pressure Granulite Facies Overprinting During The Exhumation Of Eclogites In The Bangong-Nujiang Suture Zone, Central Tibet: Link To Flat-Slab Subduction, Xiu Zheng Zhang, Qiang Wang, Yong Sheng Dong, Chunfu Zhang, Qing Yun Li, Xiao Ping Xia, Wang Xu

Geosciences Faculty Publications

The geometric transformation of a descending plate, such as from steep to flat subduction in response to a change from normal to overthickened oceanic crust during subduction, is a common and important geological process at modern or fossil convergent margins. However, the links between this process and the metamorphic evolution of the exhumation of oceanic (ultra)high-pressure eclogites are poorly understood. Here we report detailed petrological, mineralogical, phase equilibria, and secondary ion mass spectrometry zircon and rutile U-Pb age data for the Dong Co eclogites at the western segment of the Bangong-Nujiang suture zone, central Tibet. Our data reveal that the …

Pcor Partnership Atlas, Wesley D. Peck, Earl P. Battle, Megan M. Grove, Kyle A. Glazewski, Joyce M. Riske, Charles D. Gorecki, Edward N. Steadman, John A. Harju

EERC Maps and Infographics

The Plains CO₂ Reduction (PCOR) Partnership Atlas provides a regional profile of CO₂ sources and potential CO₂ storage locations across the PCOR Partnership region. The revised fifth edition provides an up-to-date look at PCOR Partnership activities, including additional regional characterization and updates on full-scale demonstration projects. Additional background information on carbon capture, utilization, and storage (CCUS) is included to give a better understanding of how CCUS addresses concerns about climate change while allowing future energy needs to be met.

Digitizing Dinosaur National Monument's Carnegie Quarry, Rebecca Esplin

Theses and Dissertations

The Carnegie Quarry in northeastern Utah is world-renowned for the dinosaur skeletons it has produced and for its in situ display of dinosaur bones. The specimens excavated at Carnegie Quarry are displayed and curated in 20 repositories, most in North America. Data on these specimens in the forms of notes, photographs, publications, field maps, and so on, are scattered in an array of formats and institutions. The primary goal of this thesis is to develop a database linking these data with a digital map (GIS system) to make them readily accessible. To this end, a relational database was created using …

Pyritized Cryogenian Cyanobacteria Fossils From Arctic Alaska, Kelsey R. Moore, Tanja Bosak, Francis Macdonald, Kimberly Du, Sharon A. Newman, Daniel J.G. Lahr, Sara B. Pruss

Geosciences: Faculty Publications

The Cryogenian was a time of climatic extremes, with two extended and severe global glaciations bracketing hothouse conditions. The effect of these extreme climate conditions on ocean chemistry and the marine biosphere remain poorly understood. Most of the previous studies of the fossil record from this interval focus on benthic organisms, with few examples of organisms with an inferred planktonic lifestyle and no firm evidence for photosynthetic organisms. Here, we present helically coiled, straight, and curved fossils composed of fine crystalline or framboidal pyrite in limestone samples from the Ikiakpuk formation of Arctic Alaska. These structures are morphologically identical to …

Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard

Electronic Theses and Dissertations

ABSTRACT

Differential dissolution of gypsum karst within the Delaware Basin poses a significant threat to infrastructure that society depends on. The study area is located in Culberson County, Texas and traverses a distance of approximately 54 kilometers along RM 652 within the Gypsum Plain which is situated on the northern margin of the Chihuahua Desert and includes outcrops of Castile and Rustler strata that host karst geohazards. Regions of karst geohazard potential have been physically surveyed proximal to the study area in evaporites throughout the Castile Formation outcrop; minimal hazards, in comparison to the Castile Formation, have been documented in …

Understanding Cigarette Butt Littering Behavior On A Public Beach: A Case Study Of Jekyll Island, Maranda R. Miller, Mark E. Burbach

Conservation and Survey Division: Faculty and Staff Publications

Conservation of natural resources and promotion of family-friendly tourism activities are vital to Jekyll Island. As it is stated in the Jekyll Island Authority (JIA) Master Plan “Jekyll Island is a unique, state-owned barrier island that balances conserving and preserving natural, historic, and cultural resources with providing accessible, affordable recreation, vacation, and education opportunities for the people of Georgia and beyond” (Jekyll Island Authority, 2014b, p. 4). The JIA has reported approximately 1 million people visit the island annually (Jekyll Island Authority, 2015). As such, tourism is instrumental to Jekyll Island’s economy, and that tourism contributes to the overall economy …

Understanding And Developing Estimates Based On Practical Foundation Methods For Alaska's Discontinuous Permafrost Region, Paul P. Dennison

Theses and Dissertations

This research uses a quantitative analysis to develop a family of curves and a calculator for potential foundation thresholds in the discontinuous permafrost region of Alaska. The United States Pacific Command (PACAF) is bolstering the region by advocating for the F-35, KC-46, and the newly proposed long-range bomber to be stationed in Alaska. These next generation aircrafts and warfighters will need new facilities and beddown plans to efficiently and effectively carry out their mission. The biggest obstacle in the region is permafrost; this unique polar phenomenon is found throughout the northern half of Alaska. Fairbanks in particular has multiple military …

Provenance Analysis Of The Grover Gravel Using Detrital Zircon Geochronology, Petrology And Heavy Mineral Analysis, Grant Spoering

Graduate Theses/Dissertations

The Grover Gravel in the St. Louis, Missouri area contains a mix of chert, quartzite, jasper, and ironstone in clast sizes ranging up to 60 cm. The gravel varies in thickness from a veneer to over 30 feet and rests on upland surfaces at elevations sometimes exceeding 300 feet above the floors of major valleys. A pre-Pleistocene age generally has been proposed or assumed for the gravel, which classically has been interpreted to be a meandering-stream deposit atop an extensive flat upland surface, which was subsequently eroded and dissected by rejuvenated streams. However, large quartzite boulders in the gravel also …

Miocene-Pliocene(?) Folds, Normal Faults And The Left-Lateral Buckhorn Fault With Regional Implications, Pahranagat Shear Zone, Nevada, Thomas Godfrey Price

UNLV Theses, Dissertations, Professional Papers, and Capstones

Strike-slip faults play an important role in the development and evolution of extensional regimes including in the intraplate extension in the Basin and Range province. The Basin and Range province is divided into the Northwestern, Northern, Central and Southern Basin and

Range subprovinces. The boundary zone between the Northern and Central subprovinces is marked by several left-lateral fault zones, including the Pahranagat Shear Zone (PSZ), Caliente-Enterprise Zone and Rock Valley Fault Zone. The PSZ has a close spatial and kinematic relationship with the left-lateral Caliente-Enterprise Zone, which lies to the NE, and a slightly more distal relationship to the left-lateral …

Phase Equilibria, Compressibility, And Thermal Analysis Of Bastnaesite-(La), Richard Lee Rowland

UNLV Theses, Dissertations, Professional Papers, and Capstones

Understanding basic material properties of rare earth element (REE) bearing minerals such as the temperatures and pressures at which different phases are thermodynamically stable and how they respond to changes in temperature and pressure can assist in understanding how economically viable deposits might form, thereby potentially leading to the discovery of new deposits. Bastnaesite is the most common REE bearing mineral mined. The lanthanum-fluoride end member, bastnaesite-(La), was synthesized. Synthetic bastnaesite-(La) and lanthanum oxyfluoride was investigated using thermal analysis at ambient pressure and high temperature through the methods of thermogravimetric analysis, differential scanning calorimetry, and heated stage powder X-ray diffraction. …

An Lntegrated Approach (Remote Sensing, Hydrogeology, Geotechnical, And Geoinformatics) To Assess And Monitor Fossil Aquifers And Associated Land Deformation Over The Arabian Peninsula, Abdullah Ghurmullah Saeed Othman

Dissertations

Deformational features such as subsidence, sinkholes, fissures, settling and cracks in buildings and structures, and earthquakes are being reported from many of the world’s arid lands, in areas where fossil aquifers are being excessively exploited. Using the Lower Mega Aquifer System (LMAS) in Arabia as a test site, I applied an integrated approach (remote sensing, geodesy, GIS, geology, hydrogeology, and geotechnical) to identify nature, intensity, spatial distribution, and factors controlling the observed deformation in the central (Al-Qassim and Ha'il regions; area: 16×10⁴ km²) and the northern (Wadi As-Sirhan Basin; area: ~10.9×10⁴ km²) Arabia. A four -fold approach was adopted to …

Receiver Function Imaging Of Mantle Transition Zone Discontinuities Beneath The Tanzania Craton And Adjacent Segments Of The East African Rift System, Muchen Sun, Kelly H. Liu, Xiaofei Fu, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The mantle transition zone (MTZ) discontinuities beneath the Tanzania Craton and the Eastern and Western Branches of the East African Rift System are imaged by stacking over 7,100 receiver functions. The mean thickness of the MTZ beneath the Western Branch and Tanzania Craton is about 252 km, which is comparable to the global average and is inconsistent with the existence of present-day thermal upwelling originating from the lower mantle. In contrast, beneath the Eastern Branch, an up to 30 km thinning of the MTZ is observed and is attributable to upwelling of higher temperature materials from either the upper MTZ …

The Impact Of Fe-Ti Oxide Concentration On The Structural Ridgity Of The Lower Oceanic Crust, Atlantis Bank, Southwest Indian Ridge, Daniel Winkler

Master's Theses

Fe-Ti oxides are important components of oceanic core complexes (OCC) formed at slow-spreading mid-ocean ridges since Fe-Ti oxides are more susceptible to crystal-plastic deformation than silicate minerals. This study investigated the predicted relationship between the presence and concentration of Fe-Ti oxides and the presence and intensity of crystal-plastic deformation in gabbroic samples from Atlantis Bank, Southwest Indian Ridge (SWIR). Atlantis Bank is an oceanic core complex that formed through the exhumation of lower oceanic crust along a detachment fault. OCCs form along slow-spreading ridges and are characterized by the complex interactions between magmatism and lithospheric extension, thus making these complexes …

Quantitative Morphological Classification Of Planetary Craterforms Using Multivariate Methods Of Outline-Based Shape Analysis, Thomas Joseph Slezak

Theses and Dissertations

Craters formed by impact and volcanic processes are among the most fundamental planetary landforms. This study examines the morphology of diverse craterforms on Io, the Moon, Mars, and Earth using quantitative, outline-based shape analysis and multivariate statistical methods to evaluate the differences between different types of. Ultimately, this should help establish relationships between the form and origin of craterforms. Developed in the field of geometric morphometrics by paleontological and biological sciences communities, these methods were used for the analysis of the shapes of crater outlines. The shapes of terrestrial ash-flow calderas, terrestrial basaltic shield calderas, martian calderas, Ionian paterae, and …

Topography Of The Mantle Transition Zone Discontinuities Beneath Alaska And Its Geodynamic Implications: Constraints From Receiver Function Stacking, Haider H. Dahm, Stephen S. Gao, Fansheng Kong, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The 410 and 660 km discontinuities (d410 and d660, respectively) beneath Alaska and adjacent areas are imaged by stacking 75,296 radial receiver functions recorded by 438 broadband seismic stations with up to 30 years of recording period. When the 1-D IASP91 Earth model is used for moveout correction and time depth conversion, significant and spatially systematic variations in the apparent depths of the d410 and d660 are observed. The mean apparent depth of the d410 and d660 for the entire study area is 417 ± 12 km and 665 ± 12 km, respectively, and the mean mantle transition zone (MTZ) …

Aquifers Of Nebraska Ii: The Niobrara Aquifer, Dana Divine, Robert Matthew Joeckel, Sue Olafsen Lackey

Conservation and Survey Division: Faculty and Staff Publications

The marine shale, chalk, marl, and chalky limestone of the Niobrara Formation directly underlie Quaternary sediments in 23 counties from south-central to northeastern Nebraska. Nevertheless, the formation serves as an aquifer only in and around Cedar, Madison, and Nuckolls counties. Niobrara aquifer wells mostly supply irrigation, domestic, and livestock needs. Two hundred of the approximately 230 active registered wells in Nebraska that are screened entirely in the Niobrara aquifer are in Cedar County and environs. About another 200 wells in this area are screened in both the Niobrara aquifer and overlying Quaternary sediments. Wells screened entirely in the Niobrara aquifer …

Dissolved Organic Carbon And Dissolved Metal Pulses During Snowmelt Runoff In The Upper Provo River Watershed, Utah, Usa, Hannah Nicole Checketts

Theses and Dissertations

Snowmelt river systems exhibit seasonal fluxes in water chemistry, potentially affecting the water supply of one-sixth of the worlds population. In this study, we examined water chemistry of the upper Provo River, northern Utah, which supplies water to over two million people along the urban Wasatch Front. Seasonal changes in water chemistry were characterized by analyzing discharge and dissolved organic carbon (DOC) with dissolved trace metal and cation concentrations (La, Pb, Cu, Al, Be, Sr and K) over three consecutive water years 20142016, with intensive sampling during snowmelt runoff. To better understand links between metal movement and DOC, we sampled …

Geological Characterization Of Precambrian Nonconformities: Implications For Injection-Induced Seismicity In The Midcontinent United States, Laura Cuccio

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The midcontinent United States, a region which typically does not experience many earthquakes, has experienced a significant increase in the number of earthquakes over the last decade. This increase in earthquake activity has been linked to wastewater injection, a process in which large volumes of wastewater from oil and gas extraction are injected into deep (2-3 km), high-permeability sedimentary rocks, near low-permeability Precambrian (>540-million-year-old) crystalline ‘basement’ rocks. The contact between these two rock types is referred to as the Precambrian nonconformity. Injection-induced earthquakes occur on or near basement-hosted faults due to an increase in pore fluid pressures, which implies …

Usarray Imaging Of North American Continental Crust, Xiaofei Ma

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The layered structure and bulk composition of continental crust contains important clues about its history of mountain-building, about its magmatic evolution, and about dynamical processes that continue to happen now. Geophysical and geological features such as gravity anomalies, surface topography, lithospheric strength and the deformation that drives the earthquake cycle are all directly related to deep crustal chemistry and the movement of materials through the crust that alter that chemistry.

The North American continental crust records billions of years of history of tectonic and dynamical changes. The western U.S. is currently experiencing a diverse array of dynamical processes including modification …

Copper Mineralogy In The Oxide Zone Of The Lone Star Porphyry Copper Deposit, Eastern Arizona, Jeff G. Selck

Theses and Dissertations

The Lone Star porphyry copper deposit in the Safford District of southeastern Arizona was discovered in the late 1800's but never mined on a large scale. In addition to typical copper oxide species such as chrysocolla, the upper part of the deposit has zones of mineralization in which the chemical assays of core samples have higher amounts of copper than can be visually assigned to the observed copper-bearing minerals. The goal of this study is to identify the Cu-bearing minerals, which is crucial because the efficiency of the extraction processes is strongly dependent upon the mineralogy. Samples from seven cores …