Earth Sciences Commons^™

Behavioral Paleoecology Of Lower Cambrian Deposit Foragers: Reinterpreting Looping And Meandering Traces Using Optimal Foraging Theory And Quantitative Analysis, Zachary Andrew Jensen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The early Cambrian was a period of transition during which the seafloor environment was changing from a microbial-mat-dominated environment to a bioturbation-dominated environment. The result was a patchy landscape of variable food resources for foraging burrowers to exploit. Looping trace fossils, such Psammichnites gigas and Taphrhelminthopsis nelsoni, appear in strata worldwide during this transitional period, and the ecological niche they filled is a subject of debate among ichnologists. The objectives of this study are (1) to determine the foraging strategies preserved by looping traces through the application of optimal foraging theory and quantitative analysis, and (2) use those results to …

Environmental Changes Across The Early Mississippian Carbon Isotope Excursion, Dev Krishna Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Early Mississippian K–O (Kinderhookian-Osagean) δ13C excursion or TICE (mid-Tournaisian carbon isotope excursion) is characterized by an anomalous carbonate carbon isotope value of ≥5‰ that has been documented from numerous stratigraphic sections across the globe. This δ13C excursion coincides with global cooling and sea-level fall and predicts a significant change in seawater chemistry. However, sulfate sulfur isotope data across the K-O δ13C excursion reported in previous studies seem not to be responsive to the carbon cycle. Likewise, a recent study has documented a unidirectional increase in nitrogen isotopes across this excursion, which is not anticipated considering the amount of organic …

Investigating The Application Of Multibeam Sonar And Remotely Operated Vehicles In Fish Population Monitoring On Artificial Reefs, Robert Figueroa-Downing

Theses and Dissertations

Implementation of ROVs and multibeam imaging sonar in fisheries research has the potential to improve the accuracy and efficiency of current monitoring practices. This study aimed to 1) compare ROV video and diver abundance estimates; 2) evaluate fish length measurement accuracy from sonar; 3) investigate key differentiating sonar characteristics. Results indicate: 1) Diver surveys captured greater diversity of species; survey methods were comparable with regards to conspicuous species (r = 0.089, p = 0.074); 2) Length measurements from multibeam imaging sonar had high predictive power (Rho = 0.998; p < 0.001) of actual standard lengths and; 3) variations between samples were largely due to swim bladder echo, relative position of the target fish, and schooling characteristics. We conclude that 1) ROVs are less apt at observing cryptic species; 2) The Blueview P900-90 sonar can accurately measure fish length; and 3) swim bladder morphology plays an important role in fish identification.

The Groundwater Atlas Of Richardson County, Nebraska, Dana P. Divine, Leslie M. Howard

Conservation and Survey Division: Faculty and Staff Publications

The purpose of this groundwater atlas is to synthesize a wealth of hydrogeologic data for Richardson County that has not been published in readily accessible formats previously. Many of the maps presented herein are based on data from registered well logs and test hole logs that are publicly available on-line, which become more valuable when compiled, analyzed, and discussed as a whole. The focus of the maps presented in this report is the accessibility of groundwater for pumping.

An Elemental Highway: Investigation Of A High Nickel Anomaly In Olivine From The Island Of Niihau, Hawaii, Alexander James Valentine

UNLV Theses, Dissertations, Professional Papers, and Capstones

The study of volcanic geochemistry is one of the main gateways for investigating the Earth’s mantle. One important topic in the field is that of nickel (Ni) in the mineral olivine. While Ni is a compatible element in olivine, its high concentration at a given MgO content is not well understood. A variety of hypotheses have been proposed, including attributing presence of Ni to pyroxenite source melting, contribution from the core, or variation in peridotite source melting. In addition to the other hypotheses, chemical diffusion may also be a mechanism for enriching olivine Ni concentration. Magnesium-iron (Mg-Fe) isotopic measurements have …

Provenance Tracing Of Glacial Sediment From The Foundation, Academy, And Recovery Ice Streams, Weddell Sea, Antarctica, Ashley Marie Cirone

Theses, Dissertations and Culminating Projects

This project seeks to advance our understanding of Antarctic Ice Sheet dynamics and to gain insight into the bedrock composition beneath the Antarctic Ice Sheet by “fingerprinting” ice streams that drain into the Ronne-Filchner Ice Shelf. The Ronne- Filchner Ice Shelf is the second largest ice shelf in Antarctica and receives ice drained from both the West and East Antarctic Ice Sheets through a series of ice streams. In response to global warming, this sector has the potential to contribute dramatically to sea level rise, especially from the Recovery Catchment. Till samples were collected from lateral moraines adjacent to the …

Determining Late Pleistocene To Early Holocene Deglaciation Of The Baltic Ice Lake Through Sedimentological And Geochemical Analysis Of Iodp Site M0064, April Lynn Kelly

Theses, Dissertations and Culminating Projects

IODP Site M0064 within the Baltic Sea’s Hanô Bay was drilled to investigate the déglaciation history of the Scandinavian Ice Sheet (SIS) from the Late Pleistocene to the Holocene. This research aims to better understand how déglaciation speed, SIS drainage patterns, and changes in relative sea level influences sediment deposition within the Baltic Ice Lake (BIL) on a high-resolution timescale. Site M0064 contains diamicton at -47 - 9 mbsf, followed by an upward transition to cm-scale grey thinly laminated rhythmites at -8 mbsf, and a sharp 2.5 cm thick dark brown organic layer at -7.87 msbf, transitioning to reddish-brown thinly …

Late Quaternary Dragon Lizards (Agamidae: Squamata) From Western Australia, Julie Rej

Electronic Theses and Dissertations

Fossil Agamidae from Western Australia have been the subject of limited study. To aid in fossil agamid identification, Hocknull (2002) examined the maxilla and dentary of several extant species from Australia and determined diagnostic characters for various species groups. In the study here, fossil agamids from two localities in Western Australia, Hastings Cave and Horseshoe Cave, were examined, grouped, and identified to the lowest unambiguous taxonomic level. Morphometric analyses were conducted to compare morphotypes, and find additional diagnostic characters. From Hastings Cave there were two maxilla morphotypes and three dentary morphotypes. Based on identifications, taxa present at this locality were …

Lost Names In The Paleozoic Lithostratigraphy Of Arkansas, Noah Morris

Graduate Theses and Dissertations

The geology of Arkansas has been studied for nearly 160 years, and our understanding of it is continually evolving. Part of this ever-changing study is the nomenclature of the stratigraphy. From the early reports to today, several lithostratigraphic names have been proposed and abandoned to improve the accuracy and clarity of the understanding of Arkansas’ geology. Over these 160 years of study, 214 names have been proposed for the Paleozoic beds of Arkansas, with nearly 80 of them currently in use today. These names are a testimony and legacy of the history of Arkansas’ natural resource development and Arkansas’ geologists. …

Using Cross-Sets For Paleodischarge Estimation And Paleocurrent Vectors In The Parthenon Sandstone, Northwest Arkansas, Sean Robert Parry

Graduate Theses and Dissertations

In this thesis, set thicknesses are used to estimate the paleohydraulics (paleodischarge and give magnitudes for paleocurrent directions) of the ancient river system which deposited the Parthenon Sandstone in northwest Arkansas. Set thickness is the vertical thickness of a group of strata conformable series (Mckee and Weir, 1953); set thickness represents truncated dunes. The goal of this thesis is to: 1) obtain paleodischarge estimates of the Parthenon sandstone via cross-sets and compare the results with previously calculated discharge estimates which use basin area to discharge collation techniques and 2) use paleodischarge estimates calculated within this thesis to give magnitude to …

Lithospheric Evaluation Of The Mid-Continental Rift System In Iowa From A Gravity And Magnetic Analysis, Moamen Mohamed Almaz

Graduate Theses/Dissertations

The Proterozoic Midcontinent Rift System (MCRS) is considered one of the most important tectonic features in North America and was formed during a continental breakup event at 1.1 Ga (billion years). The MCRS is totally covered by Phanerozoic sedimentary rocks except in the Lake Superior region. Consequently, the geological characteristics of the MCRS are primarily inferred from extrapolations from the outcrop areas, drill holes, and from a variety of geophysical investigations. Iowa has a large segment of the MCRS which to date has only been partially investigated geophysically with little information regarding the lower crustal and upper mantle structure under …

Influence Of Prescribed Burning On Upland Soil Properties In Mark Twain National Forest, Southeast Missouri Ozarks, Megan Lynn Hente

Graduate Theses/Dissertations

In the Mark Twain National forest there is a collaborative effort to restore parts of the forest to its original shortleaf pine-oak woodland areas by using a combination of silviculture and prescribed fire. The purpose of this project is to assess the effects of prescribed burning on upland forest and soil physical properties that influence erosion processes across a gradient of burned sites of different ages and unburned sites. A combination of geospatial, field, laboratory, statistical (one-way ANOVA) and modeling (USLE) methods were used to assess the effects of prescribed burns on forest and soil characteristics in Big Barren Creek …

Geomorphic Characteristics And Sediment Transport In Natural And Channelized Reaches Of Big Barren Creek, Southeast Missouri, Matthew S. Thies

Graduate Theses/Dissertations

Channelization, levee construction, and gravel mining are land management practices that are used for flood control. However, they often alter the balance between sediment supply and available sediment transporting power in streams, causing channel instability. Streams can respond to instability through channel incision and sediment aggradation which can degrade riparian habitat, increase flood risks, and cause property damage. These problems have been observed along segments of Big Barren Creek, which drains 190 km² of the Missouri Ozarks in Mark Twain National Forest. Field assessment and modeling methods were used to evaluate the spatial distribution of channel instability along the upper …

Geomorphic Effects Of Logging Railbeds On An Ozarks Headwater Stream, Mark Twain National Forest, Missouri, Nickolas S. Bradley

Graduate Theses/Dissertations

Geomorphic characteristics of headwater streams draining the Missouri Ozarks have not been studied as much as larger rivers in the region. Further, while the effects of historical logging on channel form and sediment supply have been identified, no studies have investigated the effects of logging tramways constructed along Ozark headwater rivers. This study examines the geomorphic characteristics and channel disturbances of Tram Hollow (1.67 km²) within the Mark Twain National Forest in the Ozark Highlands. The purpose of this study is to classify and quantify natural and disturbed channel morphology in Tram Hollow which has been affected by …

Deposition Patterns And Rates Of Mining-Contaminated Sediment Within A Sedimentation Basin System, S.E. Missouri, Joshua Carl Voss

Graduate Theses/Dissertations

Flooding events exert a dominant control over the deposition and formation of floodplains. The rate at which floodplains form depends on flood magnitude, frequency, and duration, and associated sediment transport capacity and supply. While it is known that sediment in the Big River is contaminated from historical mining, little is known about the patterns and rates of deposition on floodplains, especially those that have been modified for remediation purposes. The goal of this study was to evaluate the influence of flood characteristics and topography on contemporary deposition patterns and rates in a sedimentation basin system located within a floodplain along …

Using Survey Data And Hec-Ras Modeling To Assess A Riffle-Remediation Structure On The Big River, Bonne Terre, Missouri, Nichole Renee Weedman

Graduate Theses/Dissertations

Sediment transport and deposition in river channels can vary for many reasons including flooding, dredging, channel velocity, and grain size. On the Big River, the Army Corps of Engineers constructed a riffle ramp structure to trap and remediate lead-contaminated sediments. The performance of the structure is unknown. The goal of this study is to evaluate the storage capabilities of the riffle structure. To do this, survey data was collected to analyze sediment storage and entered into the HEC-RAS 5.0 to model the hydraulics of the channel before and after the riffle installation. Samples were collected to assess the level of …

Cyclostratigraphic Trends Of Δ13c In Upper Cambrian Strata, Great Basin, Usa: Implications For Astronomical Forcing, Wesley Donald Weichert

Graduate Theses/Dissertations

Composite geochemical studies of carbonate isotope values (δ13C) by other investigators have established that the Cambrian period is punctuated by a series of significant, globally correlated, positive and negative δ13C excursions. However, it remains unclear if low-amplitude secular variations in δ13C values exist superimposed on, or between large-scale perturbations in the Cambrian carbon cycle, especially in cyclic successions. Rocks of Steptoean-Sunwaptan (Paibian-Jiangshanian) stage, exposed in the Great Basin of Utah and Nevada, are excellent candidates for testing the hypothesis that sedimentary cycles record minor variations in Earth's orbit (Milankovitch cycles) through application of high-resolution chemostratigraphic analysis. High-resolution δ13C data was …

A Geophysical Analysis Of The Great Falls Tectonic Zone And The Surrounding Area, Montana Usa, Travis Lane Fultz

Graduate Theses/Dissertations

The Great Falls Tectonic Zone (GFTZ) is a northeast trending zone of high angle faults and lineaments extending from northeastern Idaho into Saskatchewan, Canada. The GFTZ is believed to have facilitated the collision between the Archean Wyoming and Hearne cratons. Previous geophysical studies have analyzed seismic refraction data across the boundary between the Paleoproterozoic GFTZ and Archean Wyoming Craton (WC), this indicated the lower crustal layer thickens as it dips beneath the boundary towards the WC. In this study, three 2 dimensional (2D) gravity models that crossed the central region of the GFTZ were produced using constraints from existing geologic …

Geochronology Of Calc-Alkaline Ash Flow Tuff Units In The Ogollon Datil Volcanic Field, Southern New Mexico: U-Pb In Zircon, Shannon Porter Rentz

Graduate Theses/Dissertations

Caldera systems are capable of outputting voluminous quantities of volcaniclastic material with wide ranging negative environmental impacts. Determining the behaviors of previously erupted caldera systems may help inform predictive models used to evaluate hazards and assess risks for analogous currently active volcanic systems. The Mogollon-Datil volcanic field (MDVF) is a 40-24 Ma cluster of caldera activity in southern New Mexico tied to the subduction, and possible delamination, of the Farallon plate beneath the North American plate. A regional ignimbrite flare up from 36-24 Ma produced at least 28 caldera-forming eruptions. The calc-alkaline magmatism of three calderas in this field (the …

Petrography And Geochemistry Of Oligocene Rhyolitic Volcanic Rocks, Western Mogollon-Datil Volcanic Field, New Mexico, Emily Elizabeth Salings

Graduate Theses/Dissertations

The Mogollon-Datil volcanic field (MDVF), located in southern New Mexico, is the remnant of extreme and punctuated volcanism over ~12 m.y. of activity. The Bursum caldera is the youngest of three nested calderas in the Mogollon Mountains in the western MDVF. Here I present data from a high-silica, large volume tuff associated with the Bursum caldera, the Bloodgood Canyon Tuff (BCT). Extensive mapping by previous workers have provided a limited whole rock geochemical dataset and descriptions of the unit, but a detailed study had not been conducted. I present new whole-rock major- and trace-element analyses, Sr, Nd, and Pb isotope …

Channel Bar Morphology, Distribution, And Mining-Related Geochemistry In The Big River, St. Francois County, Missouri: Implications For Geomorphic Recovery, Lindsay Marie Olson

Graduate Theses/Dissertations

Tailings releases associated with large-scale historical Pb mining in St. Francois County, Missouri resulted in system-wide contamination of Pb and excess sediment in the Big River. Previous studies have addressed basin and segment scale variability of the contaminants; however, little is known about reach and bar scale variability. This study addresses how mining sediment inputs influence bar form and geochemistry across a range of scales. Bar sediment samples were collected at 21 reaches and analyzed for particle size and geochemistry, while air photo analysis was used to evaluate channel morphology, bar type, and area. Bar area is initially low in …

Investigating Patterns Of Fluvial Form And Incision Near The Yellowstone Hotspot — Alpine Canyon Of The Snake River, Wyoming, Daphnee Tuzlak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The shape of a landscape is created by rivers, which erode the underlying bedrock and carve through mountains. The Snake River flows across the uplifting hotspot plume of the Yellowstone region, cuts through the Snake River Range, and ultimately enters the low-lying eastern Snake River Plain. Although there is a good understanding of the track of the Yellowstone hotspot over geologic time and shorter timescales, measurements over Quaternary timescales and an understanding of how uplift influences the rivers and landscape in the Yellowstone region are absent. We study the Snake River and its past deposits where it cuts through Alpine …

Sequence Stratigraphy, Chemostratigraphy, And Biostratigraphy Of Lower Ordovician Units In Northeastern And Western Central Utah: Regional Implications, Colter R. Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Lower to Middle Ordovician Garden City Formation and Pogonip Group are mixed carbonate and sandy marine rocks deposited on the western margin of ancestral North America. The Garden City Formation was deposited in the Northern Utah Basin and the Pogonip Group was deposited in the Ibex Basin. These two basins experienced different rates of subsidence that resulting in significant thickness differences between rock units and different rock types related to sea level change. This study provides a unique opportunity to examine changes in rock types, rock chemistry, and fossil types as sea level changed within two separate basins in …

Spatio-Temporal History Of Fluid-Rock Interaction In The Hurricane Fault Zone, Jace Michael Koger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Hurricane Fault is a 250-km long, west dipping, active Basin and Range-bounding normal fault in southwest Utah and northwest Arizona. There are multiple known hot springs along its 250-km length and multiple late Tertiary-Quaternary basaltic centers that broadly parallel the fault. Possible sources of hot spring fluids include deeply circulated meteoric water that experienced water-rock exchange at high temperatures (>100 °C) and deep-seated crustal fluids. Abundant damage zone veins, cements, and host rock alteration are present along strike, indicative of past fluid flow. Carbonate veins and cements are key features of the Hurricane Fault zone, and the primary …

Magmatic Evolution Of Early Subduction Zones: Geochemical Modeling And Chemical Stratigraphy Of Boninite And Fore Arc Basalt From The Bonin Fore Arc, Emily A. Haugen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Izu-Bonin-Mariana arc stretches south from Japan to Guam in the Western Pacific. International Ocean Discovery Project Expedition 352 drilled four core in the fore arc of the Izu-Bonin arc east of the Bonin Islands: U1439C, U1440B, U1441A, and U1442A. From the four core, 124 samples were retrieved and analyzed for major and trace elements. Two main rock types were identified: FAB and boninite. FAB is a Mid-Ocean Ridge Basalt (MORB)-like tholeiite with variable fluid mobile element enrichment such as Rb, Ba, and Sr, and low Ti/V ratios more similar to an island arc volcanic than a mid-ocean ridge volcanic. …

A Stochastic Model For Water-Vegetation Systems And The Effect Of Decreasing Precipitation On Semi-Arid Environments, Shannon A. Dixon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current climate change trends are affecting the magnitude and recurrence of extreme weather events. In particular, several semi-arid regions around the planet are confronting more intense and prolonged lack of precipitation, slowly transforming these regions into deserts. Many mathematical models have been developed for purposes of analyzing vegetation-water interactions, particularly in semi-arid landscapes. Most models are based on the average behavior of the system as a whole, and how it is influenced by external changes. These models may be termed "macro-scale" models. Other models have concerned themselves with the interactions between individuals, in this case the interactions between individual plants …

Spatiotemporal Evolution Of Pleistocene And Late Oligocene-Early Miocene Deformation In The Mecca Hills, Southernmost San Andreas Fault Zone, Amy C. Moser

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Seismogenically active faults (those that produce earthquakes) are very complex systems that constantly change through time. When an earthquake occurs, the rocks surrounding a fault (the “fault rocks”) become altered or damaged. Studying these fault rocks directly can inform what processes operated in the fault and how the fault evolved in space and time. Examining these key aspects of faults helps us understand the earthquake hazards of active fault systems.

The Mecca Hills, southern California, consist of a set of hills adjacent to the southernmost San Andreas Fault. The topography is related to motion on the San Andreas fault, which …

Hydrocarbon And Co2 Emissions From Oil And Gas Production Well Pad Soils Comparative To Background Soil Emissions In Eastern Utah, Cody S. Watkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

What effect does the development of oil and gas have on the observed air quality (i.e., increased ozone, carbon dioxide (CO₂), volatile organic compounds (VOCs), and/or methane emissions) in northeastern Utah? What percentage of these gases is natural background emissions, and what percentage is due to the recent oil and gas development in the region? Emissions in this text refer to gases released from the earth’s surface to the atmosphere. Methane is the primary compound in natural gas. Natural gas is a naturally occurring hydrocarbon gas mixture. Emissions of methane, non-methane hydrocarbons (NMHC), and CO₂ at 27 …

Riparian Buffered Sinkholes In The Blue River Watershed, Colin Copler

Undergraduate Theses

Riparian vegetation along streams has many positive effects on water quality and macroinvertebrate communities, especially in agricultural areas. Some of these effects include erosion prevention, pollutant removal, and lower summer water temperatures. There has been much research done examining the link between these riparian areas and streams; however, riparian vegetation is understudied in karst areas. Karst is a geologic formation that is composed of limestone, which dissolves in groundwater, forming sinkholes. Thus, the question this paper seeks to investigate is does riparian vegetation around sinkholes in a karst plain influence water quality within a watershed? Water quality, land cover, and …

Plant Diversity Influences The Structure And Function Of A Restored Prairie And Its Responses To Added Disturbances, Rebecca Bevans

School of Natural Resources: Dissertations, Theses, and Student Research

As global warming, human conversion of natural landscapes to agricultural uses, and widespread biodiversity losses continue to alter the ecosystems we depend on, an understanding of the relationship between ecosystem structure, composition, and function is needed to maintain valuable ecosystem states and their associated functions. Research testing the limits of an ecosystem’s ability to maintain essential structure and functioning under disturbance conditions can aid in this goal.

In this study, I measured the relationship between plant diversity, community structure and functional traits, and their responses to added disturbances. I added disturbances representing those either caused or intensified by human activity …