Geology Commons^™

Modeled Uranium Series Disequilibria In A Heterogeneous Mantle Underlying Iceland, Dana Andersen

Honors Program: Senior Projects (Public)

Regional lithologic heterogeneities in Earth’s mantle may significantly contribute to variations in magma productivity and crustal generation. Such heterogeneities may be a key factor in the anomalously high rates of magmatism and thickened crust of Iceland, which are not fully explained by the presence of a mantle plume. However, the exact lithologic composition of the mantle underlying Iceland is largely unknown. Recent trace element modeling has suggested a two-component melt source beneath Iceland, consisting of a typical upper mantle peridotite mixing with one of several compositions of pyroxenitic material. This study further investigates these potential melt sources by calculating U-series …

Dual Crosslinked Poly(Acrylamide-Co-N-Vinylpyrrolidone) Microspheres With Re-Crosslinking Ability For Fossil Energy Recovery, Jingyang Pu, Baojun Bai, Jiaming Geng, Na Zhang, Thomas Schuman

Chemical and Biochemical Engineering Faculty Research & Creative Works

Microspheres have been proposed to be applied in controlling wastewater production for mature oilfields and migrating leakage for gas and nuclear waste storage. However, it remains challenging for stacked microspheres to maintain strong blocking ability in micron-sized small pores or fractures. in this study, a novel microsphere was developed with comprehensive properties including high deformability and long re-crosslinking time upon tunable swelling ratio for the applications. a dual covalent and physical crosslinking strategy was used to develop novel microspheres reinforced by a hydrogen bond (H-bond, between pyrrole ring and amide group) and coordination bond (between chromium acetate (CrAc) and carboxyl …

Evaluating Snow And Ice Cover In Tierra Del Fuego, Argentina, Zoe Pitman

Geosciences Undergraduate Honors Theses

Evaluating changes in snow and ice cover is an important field for studying climate change and its impacts. This evaluation is commonly done using remote sensing because of its ability to evaluate large areas. The purpose of this study is to determine the reliability of one remote sensing technology, the Moderate Resolution Imaging Spectroradiometer (MODIS), by comparing it to in-situ snow and climate data from the weather station at the Austral Center for Scientific Research (CADIC). Data was converted from daily to monthly averages and was sorted into a series of graphs to compare the two data sets. Correlations were …

Experimental Methodologies In Assessing Ceramic Shrinkage In Residual Fingerprints For Archaeological Application, Luke Aaron Burnor

Electronic Theses, Projects, and Dissertations

This research evaluates the extent of ceramic shrinkage using a natural clay source that was locally available and known to be used by native populations in the American Southwest. The experiment took into account variables of temper mixture and firing temperature to assess the extent and potential need for shrinkage calibration in archaeological biometric research (specifically fingerprints). An experimental design was employed to test shrinkage rates while accounting for natural temper materials found frequently in the archaeological record including sand, grog, and quartz. The experiment evaluated whether shrinkage rates may have skewed data collected in previous studies regarding sex and …

Field Observations And Stable Isotope Analysis Of Alunite At The Sulphur Bank Mercury Mine, Clear Lake, California, David Edward Muller

Open Access Theses & Dissertations

The Sulphur Bank mercury mine is a historic mine located in Lake County, California, first exploited in the 1860s. Underground mining of mercury took place from 1873 to 1906 and open-pit mining of mercury was done from 1927 to 1957. The U.S. Environmental Protection Agency listed the Sulphur Bank mine and the adjacent Clear Lake as a Superfund site in 1990 due to mercury contamination at the mine site and in the sediment and food web of Clear Lake. Previous studies have described the vein material mineralogy and wall-rock alteration at Sulphur Bank as well as the composition of water …

Incorporating Community Science In Improving Environmental Data Quality Through Model Based Reasoning Techniques, John Gilbert Olgin

Open Access Theses & Dissertations

This dissertation will address the questions: In what ways can MBR theory be applied to designtraining that will improve the capacity of Citizen scientists to collect and analyze high quality scientific data? To what degree does this training impact their ability to formulate complex understandings of environmental problems in their Citizen? The project will be comprised of three research objectives focused in three sections, carried out with NASAâ??s GLOBE Observer Citizen Science Program:

Section 1: An analysis of existing GLOBE data will be conducted, identifying whereerrors in data collection originate. At least three principal errors will be selected from this …

Enhancing Basic Geology Skills With Artificial Intelligence: An Exploration Of Automated Reasoning In Field Geology, Perry Ivan Quinto Houser

Open Access Theses & Dissertations

This thesis explores the use of Artificial Intelligence, specifically semantics, ontologies, and reasoner techniques, to improve field geology mapping. The thesis focuses on two use cases: 1) identifying a geologic formation based on observed characteristics; and 2) predicting the geologic formation that might be expected next based upon known stratigraphic sequence. The results show that the ontology was able to correctly identify the geologic formation for the majority of rock descriptions, with higher search results for descriptions that provided more detail. Similarly, the units expected next were correctly given and if incorrect, would provide a flag to the field geologist …

Characterization Of Hematite Coated Bedrock Fault Scarps In The Northern Colorado River Extensional Corridor Near Lake Mead, Nevada, Molly E. Pickerel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fault mirrors are reflective, thin, typically <1 mm thick, fault slip surfaces in exhumed fault zones that can provide a record of thermal, chemical, and rheological changes to fault materials during deformation. This study investigates a series of hematite coated fault mirrors along bedrock fault scarps in Miocene volcanic rocks near Lake Mead, Nevada. The studied faults are located in a structurally complex area that includes NE-SW trending left-lateral strike-slip faults of the Lake Mead fault system, NW-SE right-lateral strike-slip faults of the Las Vegas Shear Zone, and N-S striking extensional faults of the Northern Colorado River Extensional Corridor.New zircon U-Pb ages from fault scarp host rocks 21-BC-03 and 21-BC-05 are and 13.86 ± 0.27 Ma and 12.90 ± 0.31 Ma (2σ standard error), respectively. New apatite (U-Th)/He dates range from 5.64 ± 0.46 Ma to 12.4 ± 0.36 Ma (2σ standard error) and are interpreted to be partially reset after eruption due to reheating. Inverse thermal history modeling in HeFTy of apatite He dates indicates a thermal history of reheating to ~65 °C which is interpreted as shallow burial around ~11 - 5 Ma followed by cooling to the surface, interpreted as exhumation between ~4.5 - 2 Ma. The zircon U-Pb ages, apatite He dates, and inverse thermal history models indicate the fault host rocks were erupted to the surface and stayed within the upper ~2 km of the crust since the Miocene. Nearly vertical fault scarps that host the fault mirror surfaces exhibit two sets of slickenlines, indicating oblique and strike-slip motion, with different orientations indicating that there have been multiple episodes of deformation along the surfaces. Three of the five studied fault scarps have E-W orientations, and one scarp is NW-SE, and one is NE-SW striking. The studied faults are interpreted to have been active during deformation associated with the Lake Mead Fault System and the Las Vegas Valley Shear Zone at 13 – 9 Ma and record both strike slip and oblique slip events in the complex strain field during this time. Micro-nano scale texture and grain morphology analysis of the hematite fault mirror volumes shows extreme strain localization along the fault mirror surface. Some fault mirrors exhibit multiple domains separated by discrete slip surfaces. Comminution and cataclasis appear to be the dominant deformation mechanisms in the fault mirror volume. Hematite textures and morphologies are consistent with observations from other fault systems that are interpreted to record aseismic to sub-seismic slip rates, and relatively low coseismic temperature rise. Fluid injection veins and post-deformation FeO mineralization in fractures are interpreted as evidence of high fluid pressures during slip and fluid circulation postdeformation. The new geochronologic and microstructural data inform on the processes operating along discrete fault surfaces in the shallow crust since the Miocene in the Lake Mead region.

Morphologic Comparisons Of Recrystallized And Neocrystallized Fibrous Amphibole Asbestos: Implications For Corresponding Health Risk Potential, Natalie G. Renkes

UNLV Theses, Dissertations, Professional Papers, and Capstones

The presence of naturally-occurring asbestos (NOA) is increasingly concerning for scientists, health and regulatory agencies, and citizens living in impacted areas. It is commonly believed that fibrous amphibole asbestos can only form through neocrystallization. In southern Nevada, NOA occurs as a result of hydrothermal alteration of granitic rock producing fibrous amphibole both as cross-cutting neocrystallized veins and via recrystallization of original magmatic hornblende crystals. Fibers with a greater aspect ratio are known to have increased toxicity. This study measured the maximum length and average width of both neocrystallized and recrystallized fibers to see if the morphologies were similar. Neocrystallized and …

Study Of Trace Elements In Southern Nevada Spring Waters And Lakes, Hyejeong Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Comprehending the natural water resource is imperative for the entire state of Nevada and of particular significance for Southern Nevada, where rapid population growth and climate change are placing significant strain on supplies. This research underscores the significance of water chemistry in identifying potential water source areas through trace elements. For the first time, the study proposed measuring the compositions of the entire suite of metal elements, ranging from Li to U, in over 40 springs in the Moapa Valley and its upper gradient valleys, utilizing the iCAP Qc ICP-MS (Inductively Coupled Plasma Mass Spectrometer) at UNLV. The research evaluated …

Critical Metals: From Granitic Pegmatites To The Anthropogenic Cycle, Dalton Mccaffrey

UNLV Theses, Dissertations, Professional Papers, and Capstones

Critical metals are vital to the functionality of the modern world. The increased diversity and usage intensity of these commodities in defense-related and strategic technologies (e.g., jet engines, rocket assemblies), modern infrastructure and products (e.g., high-strength steel, cellular phones, laptop computers), and energy-related, low-emissions technologies (e.g., nuclear reactors, solar panels, wind turbines, hybrid and electric vehicles) has drastically increased our reliance on critical metals and, thus, the United States (and global) exposure to supply restrictions. Granitic pegmatites are unique mineral deposits that represent a past, present and future resource for many (approximately half) of these critical resources. Even with the …

Geological Mapping Of Ferric And Ferrous Irons In The Apache Hills, New Mexico: Applying Landsat 8 (Oli), Spectrometry, And Geographic Information System (Gis) Methods, Sergio Gerardo Macias

Open Access Theses & Dissertations

Mineral discoveries are typically tangible on surface studies. Previous research describes mineral deposits of ferric and ferrous irons in the lithology, structures, and alluvial fans in the Apache Hills in southwest New Mexico. The research for this thesis combines and models four methods for validating and mapping the presence of Ferric and Ferrous Irons developed in weathered zones above mineral deposits. A beneficial steppingstone before exploration and discovery begins with extensive research. This study began with data acquisition and reviewing previous research and was essential for the project methods. The study combines four techniques: spectral geology (e.g., remote sensing and …

Lesson Plans In Astronomy, Ecology And Biology, Admin Stem For Success

STEM for Success Showcase

This document contains various lesson plan ideas for concepts within the fields of biology, ecology, astronomy, and geology.

Testing Pedagogical Approaches To Online Lecture: Effects Of Background Music And Interactive Video Series On Student Retention Of Prior Conception-Correcting Information On Climate Change, Roya Franseth

Honors Projects

Climate change is a pervasive element in our modern lives, yet many harbor ideas about climate change and associated climate mechanisms that are misinformed or incorrect. Ideas like these – prior conceptions (ideas that people carry with them into learning experiences about a subject) – are studied in varying degrees across fields. The geosciences do not have a particularly robust collection of research on the subject of geoscience-specific prior conceptions. At the same time, due to the COVID-19 pandemic, alternatives to in-person lecture such as online lecture have become normalized. The original aim of this paper was to determine if …

Organic Matter Quality Influences Aerobic And Anaerobic Respiration Rates In Peatland Soils, Rachel Shaw, Lauren Bryan, Madison Smith, Christian Lundy, Alexis Koehl, Grace Behrens, Mackenzie Dole, Madeleine O'Donnell

22nd Annual Celebration of Undergraduate Research and Creative Activity (2023)

The vulnerability of peatland carbon reservoirs to decomposition in a warming climate remains a key uncertainty in Earth System Models. This will be determined in part by the "quality" of the peatland organic matter, i.e. the ease by which it is decomposed by the microbial community. We developed an index of organic matter quality based on the biochemical composition of the peat. The index uses a principal components analysis of proxies based on the carbohydrate composition, hydrolysable amino acids, C:N, pH, and nutrient availability in the peat porewater. The index was compared with measurements of aerobic and anaerobic respiration rates …

Temperature Sensitivity Of Nitrogen Mineralization In Peat From A Southwestern Michigan Bog, Madison Smith, Lauren Bryan, Rachel Shaw, Mackenzie Dole, Madeleine O'Donnell

22nd Annual Celebration of Undergraduate Research and Creative Activity (2023)

In this study, we measured inorganic nitrogen (nitrate and ammonium) released from peat cores from Miner Lake bog at two temperatures to analyze the impact of climate warming on the peatland nitrogen cycle. We hypothesized a higher nitrogen release in samples incubated at warmer temperatures. Furthermore, previous research indicates shallow peat decomposes faster than deeper peat. Therefore, we hypothesized faster nitrogen mineralization in shallow samples. We collected peat cores from two locations from Miner Lake Bog in Allegan County, Michigan: a plot in the center of the bog and a sedge meadow site near the edge. Two samples for each …

Glass: The Material That Defines Us, Madisyn Rex

Honors Projects

This Honors Project is an exploration of the intersections between glass science, geology, glass art, and my own personal experience with glass.

Interspecies Differences In Food Sources For The Tropical Callichirid Shrimp Neocallichirus Spp. On San Salvador Island, Bahamas, Koji Seike, H. Allen Curran

Geosciences: Faculty Publications

At least 4 species of callichirid shrimp coexist in the shallow marine settings of San Salvador Island, an isolated, small platform of the all-carbonates Bahama Archipelago, implying that interspecific competition or trophic niche segregation occurs between these shrimp species. Carbon and nitrogen stable isotope analyses were conducted on soft tissues of 3 callichirid species, Neocallichirus cacahuate, N. grandimana, and N. maryae, to determine the food sources for each species. These analyses revealed that the isotopic trophic niches for these 3 species do not overlap. The most important food source for all 3 species was manatee grass Syringodium filiforme …

Igneous Petrology Of Rumicolca Lavas From The Peruvian Altiplano: Controls On Compositional Variability And Source Characteristics, Jacob Ladner

Student Research Symposium

Lava flow samples from the Peruvian Altiplano plateau described petrologically, mineralogically, and geochemically for investigation of of genetic relation, compositional variability, and melt source characteristics. Reflective of a metasomatically altered mantle resulting from subduction of the Nazca plate under the western margin of South America.

Carbonate Microfacies Of The Middle To Upper Pennsylvanian Cache Creek Group At Meadow Lake, British Columbia, Canada, Brennen Leidy

Undergraduate Research Conference

No abstract provided.