Geology Commons^™

Evaluating Recharge And Dynamics Of Flow In The Lower Virgin River Basin, Usa: Interpretation Of Hydrochemical And Stable Isotopic Data, Joseph Asante

UNLV Theses, Dissertations, Professional Papers, and Capstones

Because of the complex geologic setting of the Basin and Range province, groundwater flow systems of the Intermountain basins of the southwestern United States are complex and remain poorly understood. Understanding these flow systems is important for water budgeting on a regional and local scale, and development of robust numerical groundwater models for sustainable water use and protection of water-dependent ecosystems. Although for decades hydrochemistry and isotopes have been used to characterize and trace subsurface water and surface water, effectively interpreting these data are still challenging, which can be attributed to existing subjective grouping of these data and the lack …

The Fluvial Muddy Creek Formation Near Overton, Nevada, Carl Taylor Swenberg

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Muddy Creek Formation (MCF) may represent an ancestral Colorado River deposit. To test this hypothesis, I mapped exposures of the MCF within the Virgin River Depression (VRD), a rift basin in the central Basin and Range. This is the first study to analyze fluvial MCF facies and test their viability as ancestral Colorado River deposits.

Mapping, paleocurrent analysis, conglomerate provenance, and architectural elements analysis were used in order to characterize the fluvial MCF near Overton NV. Architectural elements analysis revealed that MCF fluvial facies are most closely associated with those of a high-energy sand-bed braided river system. These results …

Chemical Weathering Of The Mafic Minerals Serpentine And Olivine In Natural Environments, Julie Lynn Baumeister

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chemical weathering is a critical process that plays a key role in controlling the chemistry of natural waters, the cycling of atmospheric carbon dioxide, and the formation of soil. The weathering of silicate minerals is important because the Earth's crust is composed of approximately 92 weight percent silicate minerals. Despite an extensive literature on mineral dissolution and kinetics, relatively few studies have examined weathering of the mafic minerals serpentine and olivine, especially in a natural environment. The first chapter of this thesis provides an introduction to the minerals serpentine and olivine. The second chapter of this thesis examines the important …

From The Foreland To The Hinterland: Taphonomy Across The Cretaceous To Paleogene Sevier Retroarc Region Of Nevada, Joshua William Bonde

UNLV Theses, Dissertations, Professional Papers, and Capstones

Until 2004 very little paleobiology, let alone paleoecology, had been studied within exposures of the Sevier retro-arc foreland and hinterland, in the state of Nevada. This is due largely to poor and spotty exposure. This study focuses on taphonomic processes within three stratigraphic intervals in the foreland and hinterland of the Sevier retro-arc region, and what these taphonomic indicators reveal about the geography of the hinterland.

First, the Willow Tank Formation of southern Nevada was deposited in the foredeep of the Sevier retroarc foreland basin. This unit represents a multi-channel, aggradational, fluvial system that drained the Sevier highlands to the …

The Effects Of Salt Diapirs On The Thermal Maturity Of Surrounding Sediments In The Western Pyrenees, Spain, Nicholas Martin Downs

UNLV Theses, Dissertations, Professional Papers, and Capstones

Salt diapirs have been modeled as having a large effect on the thermal maturity of surrounding sediments as a result of the high thermal conductivity contrast between halite and other lithologies. The goal of this study was to confirm these and other theoretical predictions through sampling of three salt structures in the western Pyrenees, Spain. Stratigraphic units around these three diapirs were targeted based on their lithologies and positions relative to the diapirs. Samples were analyzed for vitrinite reflectance and quartz cementation to determine their levels of thermal maturity. Remote sensing instruments were used to attempt to measure present day …

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 …

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 …

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 …

Correlation Between Grain Dislocation Density And Orientation For Naturally Deformed Mantle Xenolith From Jagersfontein Mine, Quinton Guerrero, Quinlan Smith

Undergraduate Research Opportunities Program (UROP)

Determining the reaction of poly-crystalline structures to induced stress is an extremely difficult problem in contemporary engineering and geology. The main challenge lies in the inhomogeneity of the grains inside of the poly-crystalline structures. To predict the response of a certain polycrystalline structure to a specific stress, you must resort to one of two views on grain interaction, an orientation or propagation based model. For every material there may be certain correlations between the prediction model used and the actual deformation that occurred. Our work centers around describing the correlation of these prediction models with a sample of naturally deformed …

Pleistocene Climate In Alaska From Stable Isotopes In An Ice Wedge, Corinne Y. Griffing

UNLV Theses, Dissertations, Professional Papers, and Capstones

The CRREL permafrost tunnel offers a unique opportunity to sample ice wedges in a climate-controlled environment, penetrating frozen silts which host massive ground ice that may record Dansgaard-Oeschger (D-O) and Heinrich Events. Ice wedges in the tunnel have been dated to approximately 36-22 ka (Hamilton et al., 1988), allowing the paleoclimate of the region to be reconstructed during MIS 3, when D-O and Heinrich events were documented in various other records. These climate cycles are rapid climate oscillations that have been recognized in records from the Arctic and subarctic, and suggest that climate can rapidly shift by 10°C over millennial …

Mesozoic Burial, Mesozoic And Cenozoic Exhumation Of The Funeral Mountains Core Complex, Death Valley, Southeastern California, Mengesha Assefa Beyene

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Funeral Mountains of Death Valley National Park, CA, provide an opportunity to date metamorphism resulting from crustal shortening and subsequent episodic extensional events in the Sevier hinterland. It was not clear whether crustal shortening and thus peak temperature metamorphism in the hinterland of the Sevier-Laramide orogenic wedge have occurred whether in Late Jurassic, Early Cretaceous , Late Cretaceous or somewhere between. Particularly ambiguous is the timing of crustal shortening in the deep levels of the hinterland of the Sevier belt, now manifest in the metamorphic core complexes, and how and when these middle-to-lower crustal rocks were exhumed. A 6-point …

Lateral Variability Of Facies And Cycles In The Furongian (Late Cambrian) Carbonate Platform: An Example From The Big Horse Member Of The Orr Formation In Western Utah, U.S.A., Ratna Widiarti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Carbonate depositional cycles and sequences have been proposed to be formed by glacioeustatic sea-level changes. This mechanism would be questionable during times of high atmospheric CO2 and negligible continental ice sheets such as the supergreenhouse time in the Furongian (late Cambrian), during which limited glacioeustatic sea-level changes would be expected. A detailed sedimentological study of the Furongian Orr Formation in western Utah is aimed at testing the hypothesis that, under supergreenhouse climate conditions, most meter-scale carbonate cycles may have been formed through autocyclic processes and thus they should be laterally variable. The research was conducted in a small area ( …

Molecular Organic Geochemistry Of The Oil And Source Rocks In Railroad Valley, Eastern Great Basin, Nevada, United States, Laode Ahdyar

UNLV Theses, Dissertations, Professional Papers, and Capstones

A comprehensive geochemical study of oils from Railroad Valley, Nevada and two candidate source rock intervals from the nearby Egan Range, was conducted in order to establish oil-oil and oil-source rock correlations. Analyses consisted of total organic carbon, Rock-Eval pyrolysis, and vitrinite reflectance for source rock samples, as well as biomarker, diamondoids, and stable carbon isotope analyses on source rock extracts and oil samples.

Total organic carbon analyses showed high organic content in the Mississippian Chainman Shale. However, outcrop samples of the Paleogene Sheep Pass Formation Member B are organically lean. Strata in both of these units are immature to …

Vertebrate Taxonomic Composition, Species Diversity, And Paleoecology Of Two Pliocene Mid-Latitude, Inland-Basin Fossil Assemblages: Panaca Local Fauna (Lincoln County, Nevada) And Hagerman Local Fauna (Twin Falls County, Idaho), Vicki Lynn Meyers

UNLV Theses, Dissertations, Professional Papers, and Capstones

I studied the sedimentology, species diversity, relative abundance, paleoenvironment, and paleoecology of the vertebrate fauna of the early Pliocene (Blancan Land Mammal Age) Panaca Formation of southeastern Nevada, and I compared these data with the slightly younger Hagerman fauna of south-central Idaho. The purpose of this study is to characterize the paleoecology and species diversity of mid-latitude inland basins during the Blancan Land Mammal Age, a time of climate change and immigrating taxa from Asia and South America. This study involved surface collecting and screenwashing of the Panaca Formation sediment in Meadow Valley, as well as a compilation of data …

Serpentinite Weathering And Implications For Mars, Valerie Tu, Julie Baumeister, Rodney Metcalf, A. Olsen, Elisabeth Hausrath

Festival of Communities: UG Symposium (Posters)

In the search for life on Mars near-surface soil environments may be important habitats for life accessible to future missions. Serpentinite rocks have been documented on Mars, as well as other clay minerals including smectite and kaolinites. Previous studies of soils formed on serpentinites on Earth have documented the formation of extensive clays. Serpentinites are additionally of interest as habitats for life such as methanogens. Here we examine weathering of serpentinites from bedrock to soil surface, as a potential route for the formation of clay minerals on Mars from abundant ultramafic minerals. We additionally test for the presence of Fe-oxidizing …

2011-2012 Unlv Mcnair Journal, Cyndy Anang, Sajar Camara, Pamela Cornejo, Carla Antonieta Farcello, Ilse Anahi Garcia, Natiera Magnuson, William L. Mccurdy, Lorena Munoz, Maxym V. Myroshnychenko, Ricardo Rios, Theodore Waldeck, Barbara Wallen, Ana Zuniga, Brenda M. Aguilar, Tiffany Alexandra Alvarez, Daniel N. Erosa, Paige C. Espinosa, Carla Antonieta Farcello, Julienne Jochel Paraiso, Nathaniel Derek Phillipps, Carmen Vallin, Jacent N. Wamala, Ernesto Zamora-Ramos

McNair Journal

Journal articles based on research conducted by undergraduate students in the McNair Scholars Program

Table of Contents

Biography of Dr. Ronald E. McNair

Statements:

Dr. Neal J. Smatresk, UNLV President

Dr. Juanita P. Fain, Vice President of Student Affairs

Dr. William W. Sullivan, Associate Vice President for Retention and Outreach

Mr. Keith Rogers, Deputy Executive Director of the Center for Academic Enrichment and Outreach

McNair Scholars Institute Staff

Sequence And Chemostratigraphy Of The Middle Cambrian Succession In Nevada And Utah, Robyn A. Howley

UNLV Theses, Dissertations, Professional Papers, and Capstones

The House Range Embayment of western Utah and eastern Nevada was a prominent topographic feature on the passive margin of western North America during the middle and late Cambrian. In this study, detailed documentation of sequence boundaries, and their intervening sequences across a platform-to-basin transect of the House Range Embayment was used to establish a sequence-stratigraphic framework from which the depositional history of the embayment was deciphered. This framework was then used to test the hypothesis that the House Range Embayment formed by tectonic subsidence. In addition, the chemostratigraphic (δ13Ccarb) record across the embayment was analyzed within this framework to …

The Interaction Of Rock And Water During Shock Decompression: A Hybrid Model For Fluidized Ejecta Formation, Audrey Hughes Rager

UNLV Theses, Dissertations, Professional Papers, and Capstones

Crater and ejecta morphology provide insight into the composition and structure of the target material. Martian rampart craters, with their unusual single-layered (SLE), double-layered (DLE), and multi-layered ejecta (MLE), are the subject of particular interest among planetary geologists because these morphologies are thought to result from the presence of water in the target. Also of interest are radial lines extending from the crater rim to the distal rampart of DLE craters. Exactly how these layered ejecta morphologies and radial lines form is not known, but they are generally thought to result from interaction of the ejecta with the atmosphere, subsurface …

Carbon Isotopic Fractionation Across A Late Cambrian Carbonate Platform: A Regional Response To The Spice Event As Recorded In The Great Basin, Jonathan Lloyd Baker

UNLV Theses, Dissertations, Professional Papers, and Capstones

Geochemical models have suggested that the late Cambrian was characterized by a greenhouse climate with high pCO2. Furthermore, stableisotope analyses within the Great Basin have documented a large carbonate isotope (δ13Ccarb) excursion, known as the Steptoean Positive Carbon Isotope Excursion (SPICE). This event has been documented globally, and is interpreted as having resulted from enhanced organic carbon burial. Unless the size of carbon reservoirs in the Cambrian ocean was significantly different from those of the Cenozoic, this forcing should have resulted in a comparable carbon-isotope excursion in organic matter (δ13Corg). It is also predicted that increased organic carbon burial would …

Age And Petrogenesis Of The Roaring Mountain Rhyolites, Yellowstone Volcanic Field, Wyoming, Kathleen Marie Wooton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Extracaldera rhyolites in the Norris-Mammoth Corridor of the Yellowstone Volcanic Field (YVF) appear to be unrelated to intracaldera volcanism, resulting instead from a new crustal magma source derived from northeastward propagation of the Yellowstone “melting anomaly.” The youngest extracaldera rhyolite unit, the Roaring Mountain Member (RM), is chemically distinct from the previous extracaldera lavas, reverting to more primitive compositions.

This study suggests that the majority of the RM rhyolites erupted from the same large-scale silicic magma system. Based on geochemistry and 40Ar/39Ar geochronology, the Crystal Spring mingled rhyolite and Obsidian Cliff rhyolite erupted concurrently at 59.1 ± 2.0 ka. The …

Late Paleozoic Deformation In The Osgood Mountains And Dry Hills, Northern Nevada, Samuel A. Siebenaler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pennsylvanian (IP) and Permian (P) deposits (Etchart Formation) and structures in the northern Osgood Mountains and Dry Hills are identified and interpreted to reconstruct a late Paleozoic tectonic history for the time between the Antler and Sonoma orogenies. Mapping, field observations, fusulinid-based unit ages, and structural analysis are used to identify three fold and fault sets, a fault set, a fold set, and at least two angular unconformities. The faults consist of N to S striking normal faults (fault set 1) that are cross cut by WSW-ENE striking thrust faults (fault set 2). Fault sets 1 and 2 are cross …

Rare Earth Element Transport In The Yucca Mountain Region, Liqiong Zhang

UNLV Theses, Dissertations, Professional Papers, and Capstones

In sync with environmental pollution of solutes in nature, from source, process to consequence, geochemical processes (leaching and sorption) and hydraulic transportation of the rare earth elements (REEs) have been investigated at Yucca Mountain (YM), Nevada. This research includes the leaching behavior of trace elements (including REEs) from aquifer rocks, the surface complexation reactions of REEs in synthetic groundwater, and transportation of reactive REEs in the local-scale groundwater system of YM. This dissertation includes three projects. These studies indicate that surface complexation reactions may retard the transportation of REEs along groundwater paths in YM, which suggests a similar behavior of …

Great Basin Center For Geothermal Energy, Wendy Calvin

Nevada Renewable Energy Consortium Meeting

The second annual Nevada Renewable Energy Consortium meeting took place at UNLV on August 20. The meeting focused on the current three NVREC program areas: Solar, Biomass and Geothermal. Presentations were made by participating entities and a poster session followed.

The Effects Of Contact Metamorphism On The Host Rocks For Carlin-Type Mineralization At The Getchell Development, Nevada, Usa, Nathan C. Eck

UNLV Theses, Dissertations, Professional Papers, and Capstones

Carlin-type gold deposits (CTGDs) result from low to moderate temperature hydrothermal systems which form replacement bodies in carbonate or calcareous host rocks. The Getchell CTGD is located on the Getchell trend in north central Nevada. The Eocene age mineralization is locally hosted within the metamorphic aureole of the Cretaceous age Osgood stock. Previous studies have noted that the effects of the contact metamorphism can be heterogeneous, with strongly calc-silicate altered carbonates transitioning to relatively pristine limestone over short distances. The main finding of this study was that the variability in calc-silicate alteration is largely dependent on the differing host lithologies …

Petrogenesis Of The Greenwater Range: Comparison To The Crater Flat Volcanic Field And Implications For Hazard Assessment, Ashley Kaye Tibbetts

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pliocene basalts of the Greenwater Range, California erupted from 24 volcanic vents now represented by volcanic plugs, craters and scoria mounds. Basaltic magmas originated in the asthenospheric mantle, but show evidence of a lithospheric component. Depths and temperatures of melting calculated using a silica activity geobarometer are 54.3–89.6 km and 1367-1435oC, placing melting in the asthenosphere. The preferred petrogenetic model involves melting of lithospheric mantle thermally and mechanically, but not chemically, converted to asthenospheric mantle. Melting depths correspond to low velocity zones in the mantle as revealed in seismic profiles. Chemical and lithologic similarities between basalt in the Greenwater Range …

An Experimental Investigation Of Chemical Mass Transfer Processes In Crystallizing, Hydrous Silicate Magmas: The Genesis Of Ore Deposits And Metasomatic Fluids, Aaron S. Bell

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is comprised of three broadly related experimental petrology projects on phase equilibria and noble metal solubility in hydrous silicate melts. Chapters two and three combine experimental petrology with high precision laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis of experimental run products in order to quantitatively constrain the behavior of the investigated metals. Chapter four presents experimental evidence detailing a novel oxidation mechanism for degassing silicate liquids as well as exploring the geochemical consequences of the proposed mechanism.

Chapter two presents the results of an experimental study on Au, Pt, and Pd behavior in coexisting silicate melt-sulfide-oxide …

Phyllosilicate Mineralogy, 40ar/39ar Geochronology, And Genesis Of Petrocalcic Soils In The Southwest U.S.A., Colin R. Robins

UNLV Theses, Dissertations, Professional Papers, and Capstones

Obtaining isotope ages for arid soils and paleosols, including carbonate-cemented (calcic and petrocalcic) horizons, constitutes a significant challenge for soil scientists, geomorphologists, and stratigraphers. Carbonate-cemented soils foster diverse suites of authigenic minerals with exciting potential for geochronology, however, this potential has not been realized. This dissertation describes the timing of pedogenic palygorskite and sepiolite crystallization in extremely old, extant petrocalcic soils of the southwest U.S.A., and assumes that these fibrous, high-magnesium phyllosilicates contain sufficient lattice-bound K to warrant vacuum-encapsulated 40Ar/39Ar geochronology. This three-part study evaluated the (1) selective extraction, (2) 40Ar/39Ar analysis, and (3) pedogenesis of palygorskite and sepiolite.

Effects …

Using Fluid Inclusions To Trace Formative Fluid Evolution At The Verde And Pancho Porphyry Au Deposits Of The Refugio District, Chile, Brian Joshua Aillaud

UNLV Theses, Dissertations, Professional Papers, and Capstones

Evolution of magmatically-derived formative fluids, and the processes that control the ratio of ore metals in porphyry and high-sulfidation epithermal deposits remain enigmatic. The Refugio district in the Maricunga Belt of Northern Chile hosts the temporally and spatially related Pancho and Verde porphyry gold deposits. Vein types at Pancho include A-veins, transitional veins, banded veins, D-veins and quartz-alunite ledges that formed by replacement. Verde East and West lack A-veins, and show an earliest vein type with transitional characteristics of A- to banded veins, banded veins and D-veins. Fluid inclusions and quartz textures were characterized by using optical microscopy and cathodoluminesence …

The Sheep Pass Formation, A Record Of Late Cretaceous And Paleogene Extension Within The Sevier Hinterland, East-Central Nevada, Peter Alexander Druschke

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Sevier hinterland of western North America is considered by many to be an ancient proxy for the modern Andean Puna-Altiplano or Tibetan Plateau. However, controversies exist as tectonic setting and overall paleogeography of the Sevier hinterland during the Late Cretaceous and Paleogene. The Sheep Pass Formation type section within the southern Egan Range of east-central Nevada comprises a > 1 km thick sedimentary succession spanning the latest Cretaceous to Eocene, and provides a rare opportunity to test prevailing tectonic and paleogeographic models for the Sevier hinterland. New 1:12,000 scale field mapping inthe southern Egan Range indicates that up to three …