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2020

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Articles 121 - 150 of 405

Full-Text Articles in Geology

Volcanic Record Of The Arc-To-Rift Transition Onshore Of The Guaymas Basin In The Santa Rosalía Area, Gulf Of California, Baja California, Graham Dm Andrews Aug 2020

Volcanic Record Of The Arc-To-Rift Transition Onshore Of The Guaymas Basin In The Santa Rosalía Area, Gulf Of California, Baja California, Graham Dm Andrews

Faculty & Staff Scholarship

The Gulf of California is an archetype of continental rupture through transtensional rifting, and exploitation of a thermally weakened arc to produce a rift. Volcanic rocks of central Baja California record the transition from calcalkaline arc magmatism, due to subduction of the Farallon plate (ca. 24–12 Ma), to rift magmatism, related to the opening of the Gulf of California (<12 Ma). In addition, a suite of postsubduction rocks (<12 Ma), referred to as “bajaites,” are enriched in light rare-earth and other incompatible elements (e.g., Ba and Sr). These are further subdivided into high-magnesian andesite (with 50%–58% SiO2 and MgO >4%) and adakite (>56% SiO2 and MgO <3%). The bajaites correlate spatially with a fossil slab imaged under central Baja and are inferred to record postsubduction melting of the slab and subduction-modified mantle by asthenospheric upwelling associated with rifting or slab breakoff. We report on volcanic rocks of all three suites, which surround and underlie the Santa Rosalía sedimentary rift basin. This area represents the western margin of the Guaymas basin, the most magmatically robust segment of the Gulf of California rift, where seafloor spreading occurred in isolation for 3–4 m.y. (starting at 6 Ma) before transtensional pull-apart basins to the north and south ruptured the continental crust. Outcrops of the Santa Rosalía area thus offer the opportunity to understand the magmatic evolution of the Guaymas rift, which has been the focus of numerous oceanographic expeditions.

We describe 21 distinct volcanic and hypabyssal map units in the Santa Rosalía area, using field characteristics, petrographic data, and major- and trace-element geochemical data, as well as zircon isotopic data and …


The Legacy Of Mining In Southwest Missouri: Past And Present Conditions Of The Tri-State Mining District, Anastasia M C Mcclanahan Aug 2020

The Legacy Of Mining In Southwest Missouri: Past And Present Conditions Of The Tri-State Mining District, Anastasia M C Mcclanahan

Graduate Theses/Dissertations

The historic Tri-State Mining District (TSMD) of southwestern Missouri, southeastern Kansas, and northeastern Oklahoma has a history of lead and zinc mining that extended over a hundred years. During the district’s peak production period, the TSMD was one of the world’s largest producers of lead and zinc. The mining activities in the TSMD produced economic growth that supported the local communities and were essential to the victory of the Allied Forces during World War I and World War II. Beginning in the 1920s, the mining activities in the district slowly began to cease due to depletion of metal ores and …


A Geochemical And Statistical Investigation Of The Big Four Springs Region In Southern Missouri, Jordan Jasso Vega Aug 2020

A Geochemical And Statistical Investigation Of The Big Four Springs Region In Southern Missouri, Jordan Jasso Vega

Graduate Theses/Dissertations

The Big Four Springs region hosts four major first-order magnitude springs in southern Missouri and northern Arkansas. These springs are Big Spring (Carter County, MO), Greer Spring (Oregon County, MO), Mammoth Spring (Fulton County, AR), and Hodgson Mill Spring (Ozark County, MO). Based on historic dye traces and hydrogeological investigations, these springs drain an area of approximately 1500 square miles and collectively discharge an average of 780 million gallons of water per day. The rocks from youngest to oldest that are found in Big Four Springs region are the Cotter and Jefferson City Dolomite (Ordovician), Roubidoux Formation (Ordovician), Gasconade Dolomite …


Traffic Impacts Of The Covid-19 Pandemic: Statewide Analysis Of Social Separation And Activity Restriction, Scott Parr, Brian Wolshon, John Renne, Pamela Murray-Tuite, Karl Kim Aug 2020

Traffic Impacts Of The Covid-19 Pandemic: Statewide Analysis Of Social Separation And Activity Restriction, Scott Parr, Brian Wolshon, John Renne, Pamela Murray-Tuite, Karl Kim

Faculty Publications

The COVID-19 pandemic resulted in significant social and economic impacts throughout the world. In addition to the health consequences, the impacts on travel behavior have also been sudden and wide ranging. This study describes the drastic changes in human behavior using the analysis of highway volume data as a representation of personal activity and interaction. Same-day traffic volumes for 2019 and 2020 across Florida were analyzed to identify spatial and temporal changes in behavior resulting from the disease or fear of it and statewide directives to limit person-to-person interaction. Compared to similar days in 2019, overall statewide traffic volume dropped …


A Gis-Based Method For Archival And Visualization Of Microstructural Data From Drill Core Samples., Elliott Holmes Aug 2020

A Gis-Based Method For Archival And Visualization Of Microstructural Data From Drill Core Samples., Elliott Holmes

Electronic Theses and Dissertations

Core samples obtained from scientific drilling could provide large volumes of direct microstructural and compositional data, but generating results via the traditional treatment of such data is often time-consuming and inefficient. Unifying microstructural data within a spatially referenced Geographic Information System (GIS) environment provides an opportunity to readily locate, visualize, correlate, and explore the available microstructural data. Using 26 core billet samples from the San Andreas Fault Observatory at Depth (SAFOD), this study developed procedures for: 1. A GIS-based approach for spatially referenced visualization and storage of microstructural data from drill core billet samples; and 2. Producing 3D models of …


Field Measurements Of Bed-Load Transport Distances Using Painted Sediment Tracers In An Urban Stream In The Missouri Ozarks, Kristen E. Breckenridge Aug 2020

Field Measurements Of Bed-Load Transport Distances Using Painted Sediment Tracers In An Urban Stream In The Missouri Ozarks, Kristen E. Breckenridge

Graduate Theses/Dissertations

Predictions of bed-load mobility and transport in stream channels are useful for restoration and management purposes. This study uses native gravel tracers to determine transport distances for bed-load in an urban stream in the Ozark Highlands. The objectives of this project are to: (i) determine downstream transport distances of painted tracers of different sizes over a range of flow conditions; (ii) evaluate the influence of channel morphology and thalweg location on transport; and (iii) compare field results to those predicted by mobility equations. The study site is located on South Creek, which drains Springfield, Missouri. The study reach is 132 …


Assessment Of Landslide Susceptibility At Canada Hill In Miri, Sarawak, Telun Daniel Marelyn Aug 2020

Assessment Of Landslide Susceptibility At Canada Hill In Miri, Sarawak, Telun Daniel Marelyn

Student Works (2020-2029)

Landslide occurrences have become a common sight in Miri, Sarawak due to the combination of unfavourable geological conditions, abundant rainfall and anthropogenic factors which leads to infrastructural damages following prolonged rainfall. Two of the major landslide events caused the demise of two lives and several damaged houses at Kampung Lereng Bukit. Events like this may recur if the landslide hazards are not effectively managed. Numerous studies on landslide susceptibility have been performed by researchers using different approaches. This study aims to evaluate the landslide susceptibility of Canada Hill area in Miri using a heuristic approach and bivariate statistical approach which …


Detrital Zircon Petrochronology For Sedimentary Provenance Analysis: Source To Sink Of The Mississippi/Missouri River Drainage Basin, Sage Denali Muttel Aug 2020

Detrital Zircon Petrochronology For Sedimentary Provenance Analysis: Source To Sink Of The Mississippi/Missouri River Drainage Basin, Sage Denali Muttel

Graduate Theses/Dissertations

Detrital petrochronology can provide a detailed look into sedimentary provenance through integrated mineral radioisotopic ages with corresponding mineral chemistry. By combining U-Pb ages and Th/U values of detrital zircon from 13 samples collected from Quaternary sand deposits in the Upper Missouri, Yellowstone, Bighorn, Platte, Kansas, Arkansas, Mississippi, Red and Brazos Rivers, an interpretation of detailed signatures that record evidence of the evolution of the Mississippi/Missouri River drainage and the tectonic events that shaped it were observed. Low Th/U values in zircon correlate temporally to convergent magmatism, whereas, higher and more variable Th/U zircon are coeval with known extensional tectonism. Using …


Connections Between Hydrothermal System Geochemistry And Microbiology: Traversing Tectonic Boundaries In The South-Central Peruvian Andes, Heather Upin Aug 2020

Connections Between Hydrothermal System Geochemistry And Microbiology: Traversing Tectonic Boundaries In The South-Central Peruvian Andes, Heather Upin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geochemistry and microbiology are inherently tied in the natural world. The study of geomicrobiology has historically taken place in extreme systems, like hot springs of Yellowstone National Park and deep-sea hydrothermal vents, because the organisms that exist there have deep lineages on the tree of life and provide insight into early life on Earth. These microbes use chemical energy from nutrients available in their environment rather than relying on photosynthesis, energy obtained from the sun, to support their metabolism. The goal of this study is to improve our understanding of geological controls (for example the tectonic setting) on hot spring …


Statistical Downscaling Techniques To Enhance The Spatial Resolution Of The Grace Satellite Data And To Fill Temporal Gaps, Hossein Sahour Aug 2020

Statistical Downscaling Techniques To Enhance The Spatial Resolution Of The Grace Satellite Data And To Fill Temporal Gaps, Hossein Sahour

Dissertations

The Gravity Recovery and Climate Experiment (GRACE) has been successfully used to monitor variations in terrestrial water storage (GRACETWS ) and groundwater storage (GRACEGWS) across the globe, yet such applications are hindered on local scales by the limited spatial resolution of GRACE data. Using the Lower Peninsula of Michigan as a test site, I developed optimum procedures to downscale GRACE Release-06 monthly mascon solutions. A four-fold exercise is conducted. Cluster analysis is performed to identify the optimum number and distribution of clusters (areas) of contiguous pixels of similar geophysical signals (GRACETWS time series); three clusters are …


Three-Dimensional (3d) Characterization Of The Middle Ordoovician (Darriwilian) Strata In The Southern Great Basin, Western United States, Uday Mohamed Baheej Kara Ali Aug 2020

Three-Dimensional (3d) Characterization Of The Middle Ordoovician (Darriwilian) Strata In The Southern Great Basin, Western United States, Uday Mohamed Baheej Kara Ali

UNLV Theses, Dissertations, Professional Papers, and Capstones

Carbonates are mostly produced in shallow-marine environments and their deposition is sensitive to water depth changes on carbonate platforms. The water depth in depositional environments of a particular carbonate platform is controlled by the interplay of eustatic sea-level change, tectonic subsidence, platform morphology, and depositional rate. Due to the morphological variations of carbonate platforms in different tectonic settings, facies distribution across carbonate platforms varies significantly even during a single eustatic sea-level cycle. Carbonate platforms developed on passive continental margins are thought to be the most stable platforms and their facies distribution is commonly taken as examples in textbook depositional models. …


Experimental Polycrystal Stress Mapping Using Raman Spectroscopy, Genevieve C. Kidman Aug 2020

Experimental Polycrystal Stress Mapping Using Raman Spectroscopy, Genevieve C. Kidman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Stress conditions leading to rock deformation influence how a rock will ultimately deform. However, the internal distribution of stress in an elastically anisotropic rock under load, a precursor to rock deformation, is not well understood. Two models that may describe the distribution of stress in polycrystals include the Reuss bound and stress percolation. The Reuss bound, when applied to a polycrystal, describes isostress on each grain resulting in homogeneous intragranular strain and heterogeneous intergranular strain. The stress percolation model involves a network of strong contacts or force chains containing domains of high stress interwoven through areas of lower stress that …


Quaternary Shelf-Slope Development In The Northern Gulf Of Alaska From Combined Geophysical And Geomorphologic Analysis, Wesley A. Clary Jul 2020

Quaternary Shelf-Slope Development In The Northern Gulf Of Alaska From Combined Geophysical And Geomorphologic Analysis, Wesley A. Clary

Earth and Planetary Sciences ETDs

This dissertation follows the hybrid format as defined by the Office of Graduate Studies at the University of New Mexico. The three chapters defined herein were prepared as manuscripts to be submitted for publication in peer reviewed journals in the field of Earth sciences. A version of chapter 1 was published in Proceedings of the Integrated Ocean Drilling Program, 2017, Volume 41. Chapter 2 was submitted to Marine Geology in Feb 2020, and is under revision as of this date. A version of chapter 3 will be submitted to the Journal of Geophysical Research. In chapter 1, I …


Quantitative Analyses Of Cirques On The Faroe Islands: Evidence For Time Transgressive Glacier Occupation, Keyleigh N. Wallick, Sarah M. Principato Jul 2020

Quantitative Analyses Of Cirques On The Faroe Islands: Evidence For Time Transgressive Glacier Occupation, Keyleigh N. Wallick, Sarah M. Principato

Student Publications

This study presents the first analysis of ice‐free cirques on the Faroe Islands using a Geographical Information System (GIS) and the Automated Cirque Metric Extraction (ACME) tool. The length, width, area, circularity, mean aspect, mean slope, and elevation range, minimum, and maximum were calculated using ACME. Cirque distance to coastline was measured using ArcGIS. A total of 116 cirques were identified. Mean cirque length is 950 m and mean cirque width is 890 m. Average cirque area is 0.8 km2 and mean elevation is 386 m a.s.l. The modal orientation of the aspect of cirques is north‐northeast, with a vector …


A Framework For Aquatic Invasive Species Surveillance Site Selection And Prioritization In The Us Waters Of The Laurentian Great Lakes, Andrew J. Tucker, W. Lindsay Chadderton, Gust Annis, Alisha D. Davidson, Joel Hoffman, Jon Bossenbroek, Stephen Hensler, Michael Hoff, Erika Jensen, Donna R. Kashian, Sarah Lesage, Timothy Strakosh Jul 2020

A Framework For Aquatic Invasive Species Surveillance Site Selection And Prioritization In The Us Waters Of The Laurentian Great Lakes, Andrew J. Tucker, W. Lindsay Chadderton, Gust Annis, Alisha D. Davidson, Joel Hoffman, Jon Bossenbroek, Stephen Hensler, Michael Hoff, Erika Jensen, Donna R. Kashian, Sarah Lesage, Timothy Strakosh

Environmental Science and Geology Faculty Research Publications

Risk-based prioritization for early detection monitoring is of utmost importance to prevent and mitigate invasive species impacts and is especially needed for large ecosystems where management resources are not sufficient to survey all locations susceptible to invasion. In this paper we describe a spatially-explicit and quantitative approach for identifying the highest risk sites for aquatic invasive species (AIS) introduction into the United States’ waters of the Laurentian Great Lakes, a vast inland sea with a surface area of 246,049 square km and a shoreline length of 16,431 km. We compiled data from geospatial metrics available across all of the US …


Testing The Correlation Of Trace Element Characteristics With The Petrology And Temperature Of Eruption Of Mid-Miocene Rhyolites In Eastern Oregon, Brianna Christine Young Jul 2020

Testing The Correlation Of Trace Element Characteristics With The Petrology And Temperature Of Eruption Of Mid-Miocene Rhyolites In Eastern Oregon, Brianna Christine Young

Dissertations and Theses

The Lake Owyhee Volcanic Field (LOVF) in eastern Oregon experienced several major eruptive events during the mid-Miocene (16.8 to 15.5 Ma), resulting in the emplacement of 3,900 km3 of rhyolitic lava flows and ash-flow tuffs. Eighteen samples from eleven different silicic centers in the LOVF were selected for this study. While all samples of this study are classified as rhyolite, their compositions vary greatly in terms of trace and major elements. Using trace elements, these rhyolite samples are classified as "A-type", described as resulting from "hot and dry" magmas and associated with hot-spot activity, or as "I-type" or "calc-alkaline", …


Fire Suppression Impacts On Fuels And Fire Intensity In The Western U.S.: Insights From Archaeological Luminescence Dating In Northern New Mexico, Christopher I. Roos, Tammy M. Rittenour, Thomas W. Swetnam, Rachel A. Loehman, Kacy L. Hollenback, Matthew J. Liebmann, Dana Drake Rosenstein Jul 2020

Fire Suppression Impacts On Fuels And Fire Intensity In The Western U.S.: Insights From Archaeological Luminescence Dating In Northern New Mexico, Christopher I. Roos, Tammy M. Rittenour, Thomas W. Swetnam, Rachel A. Loehman, Kacy L. Hollenback, Matthew J. Liebmann, Dana Drake Rosenstein

Geosciences Faculty Publications

Here, we show that the last century of fire suppression in the western U.S. has resulted in fire intensities that are unique over more than 900 years of record in ponderosa pine forests (Pinus ponderosa). Specifically, we use the heat-sensitive luminescence signal of archaeological ceramics and tree-ring fire histories to show that a recent fire during mild weather conditions was more intense than anything experienced in centuries of frequent wildfires. We support this with a particularly robust set of optically stimulated luminescence measurements on pottery from an archaeological site in northern New Mexico. The heating effects of an October 2012 …


The Rocky Ledge Fault, Shasta County, Ne California: Development And Morphology Of A Quaternary Oblique Normal Fault In Basalt, Gregory David Linscott Martin Jul 2020

The Rocky Ledge Fault, Shasta County, Ne California: Development And Morphology Of A Quaternary Oblique Normal Fault In Basalt, Gregory David Linscott Martin

Dissertations and Theses

Distinct morphology, variable vertical separation, and unique structural geometries are observed along the Rocky Ledge fault (RLF), an east-dipping, oblique normal fault in the tectonically complex Hat Creek Graben, Shasta County, NE California. Situated in the southern Cascade arc, the RLF is located at the boundary of the Klamath Mountains, Basin and Range, and Walker Lane Seismic Belt. The primary goal of this project is to better understand Quaternary deformation along the RLF. I developed detailed maps of geologic units and structures along the ~15 km length of the RLF. Map data informs assessment of fault geometry, scarp morphology, and …


Fluvial Geomorphic And Hydrologic Evolution And Climate Change Resilience In Young Volcanic Landscapes: Rhyolite Plateau And Lamar Valley, Yellowstone National Park, Benjamin Newell Burnett Jul 2020

Fluvial Geomorphic And Hydrologic Evolution And Climate Change Resilience In Young Volcanic Landscapes: Rhyolite Plateau And Lamar Valley, Yellowstone National Park, Benjamin Newell Burnett

Earth and Planetary Sciences ETDs

Quaternary volcanism associated with the last caldera cycle in Yellowstone National Park included emplacement of ash-flow tuffs, massive rhyolite flows ranging from 79 to 484 ka, and valley-filling basalts. This study examines (1) the evolution of spring hydrology with flow age on the Rhyolite Plateau, (2) initial development and evolution of stream networks on the rhyolite flows, and (3) the impact of the 630 ka caldera formation and volcanic flow emplacement on Lamar Valley incision rates.

Integrated stream networks formed within 79 kyr on the Rhyolite Plateau. Incision is focused on steep flow margins and knickpoints and is dependent on …


Neogene Drainage Reversal And Colorado Plateau Uplift In The Salt River Area, Jordan Curtis Anderson Jul 2020

Neogene Drainage Reversal And Colorado Plateau Uplift In The Salt River Area, Jordan Curtis Anderson

Earth and Planetary Sciences ETDs

The modern Salt River flows southwest from the Colorado Plateau, through the Arizona Transition Zone and into to the Basin and Range. Rivers in this area flowed northeast during the Paleogene from the Laramide Mogollon Highlands into structural basins of the topographically lower southern Colorado Plateau area. One of these rivers carved the Salt River paleocanyon through a portion of the Mogollon Highlands known as the Apache Uplift to similar depths as the modern Grand Canyon. This study refines the timing of this drainage reversal in the Salt River area by constraining the ages of paleoriver sediments deposited during the …


Triple Oxygen Isotope Composition Of Carbonates, Jordan A.G. Wostbrock Jul 2020

Triple Oxygen Isotope Composition Of Carbonates, Jordan A.G. Wostbrock

Earth and Planetary Sciences ETDs

This dissertation presents a method of analyzing the triple oxygen isotope compositions of carbonates, presents an empirical calibration of the carbonate-water equilibrium fractionation line, presents a triple oxygen isotope equipped fluid-rock mixing model for carbonates to see-through diagenesis, and applies all these findings to ancient carbonate samples. Using modern carbonates and associate water, the following equations are calculated to describe equilibrium triple oxygen isotope fractionation of carbonates:

1000lnalpha18Occ-wt=2.84x106/T2-2.96 1),

Thetacc-wt=-1.39/T+0.5305 2).

Using these fractionation equations provides an extremely useful tool to determine whether a carbonate sample is altered or preserves …


Response Of Transient Base Level Signals To Erodibility Contrasts In Bedrock Streams, Joshua A. Wolpert Jul 2020

Response Of Transient Base Level Signals To Erodibility Contrasts In Bedrock Streams, Joshua A. Wolpert

LSU Master's Theses

It has long been recognized that bedrock streams gradually adjust their slopes towards topographic steady state, an equilibrium state between rock uplift rate and erosion rate. Tectonic geomorphology studies often analyze stream profiles for clues of this adjustment, which can initiate from changes in tectonic and climatic forcings. The stream power incision model, the most widely utilized framework with which to interpret bedrock stream profiles, predicts that streams perturbed from topographic steady state by changes in bedrock erodibility or uplift rate adjust their slopes to return to topographic steady state through upstream propagating waves of incision, or knickpoints. Under the …


Hydrogeochemical Characterization And Speleogenesis Of Sistema Huautla In Oaxaca, Mexico, Fernando Hernandez Jul 2020

Hydrogeochemical Characterization And Speleogenesis Of Sistema Huautla In Oaxaca, Mexico, Fernando Hernandez

Masters Theses & Specialist Projects

Sierra Mazateca, Mexico is home to Sistema Huautla, the deepest cave in the Western hemisphere with 1,560 meters of depth and 90 kilometers of passage, including 26 entrances distributed in a high-relief, karstified terrain, within the Sistema Huautla Karst Groundwater Basin. Exploration of the cave has generated research questions about its evolution and geomorphology given the different vadose and phreatic zones impacted by tectonic and incision processes. Dye traces during this study of Cueva de La Peña Colorada confirmed it is a fossil resurgence of the cave system. An additional cave, Cueva Elysium, was connected hydrologically in 2019, expanding the …


A Bayesian Framework To Unravel Food, Groundwater, And Climate Linkages: A Case Study From Louisiana, Nitin K. Singh, Ruchi Bhattacharya, David M. Borrok Jul 2020

A Bayesian Framework To Unravel Food, Groundwater, And Climate Linkages: A Case Study From Louisiana, Nitin K. Singh, Ruchi Bhattacharya, David M. Borrok

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Advancing our understanding of the connections among groundwater, food, and climate is critical to meet global food demands while optimizing water resources usage. However, our understanding of the linkages among groundwater, food, and climate is still limited. Here, we offer a Bayesian framework to simulate crop yield at a regional scale and quantify its relationships and associated uncertainty with climate, groundwater, agricultural, and energy-related variables. We implemented the framework in the rice-producing regions of Louisiana from 1960-2015. To build a parsimonious model, we used a probability-based variable selection approach to detect the key drivers of rice yield. Rice yield increased, …


Environmental Influences On Tree-Driven Karst Bedrock Physical Weathering, Cole Robert Jimerson Jul 2020

Environmental Influences On Tree-Driven Karst Bedrock Physical Weathering, Cole Robert Jimerson

Graduate Theses and Dissertations

The role of tree roots as stressors that contribute to physical weathering processes and thus soil generation remains an open question in critical zone science. While evidence suggests roots may be able to damage rock by accessing pre-existing fractures, where they can expand due to water uptake or generate forces on rock in response to wind gusts, these processes have not been investigated in temperate karst regions until now. I monitored forces at the root-rock interface for an American elm and Hackberry tree between September 2019 and May 2020. I used piezoelectric force sensors to determine if differences in species, …


Characterizing Peridotite Xenoliths From Southern Vietnam: Insight Into The Underlying Lithospheric Mantle, Kirby Hobbs Jul 2020

Characterizing Peridotite Xenoliths From Southern Vietnam: Insight Into The Underlying Lithospheric Mantle, Kirby Hobbs

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Extrusion tectonics has been invoked to explain the extensive basaltic magmatism that has erupted over Indochina within the last 17 Ma. The basalts display two-stage eruptive cycles consisting of tholeiites followed by alkaline basalts. Lithospheric mantle xenoliths recently sampled from the alkaline basalts of two volcanic centers, Pleiku and Xuan Loc, primarily consist of fertile spinel lherzolites, and Xuan Loc also contains refractory spinel harzburgites. We measured major elements in xenolith mineral separates, trace elements in clinopyroxenes and orthopyroxenes, and Pb-Sr-Nd isotopic compositions in clinopyroxenes to determine the origin and history of the subcontinental lithospheric mantle (SCLM) beneath Vietnam. Most …


Groundwater Storage Loss Associated With Land Subsidence In Western United States Mapped Using Machine Learning, Ryan G. Smith, Sayantan Majumdar Jul 2020

Groundwater Storage Loss Associated With Land Subsidence In Western United States Mapped Using Machine Learning, Ryan G. Smith, Sayantan Majumdar

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Land subsidence caused by groundwater extraction has numerous negative consequences, such as loss of groundwater storage and damage to infrastructure. Understanding the magnitude, timing, and locations of land subsidence, as well as the mechanisms driving it, is crucial to implementing mitigation strategies, yet the complex, nonlinear processes causing subsidence are difficult to quantify. Physical models relating groundwater flux to aquifer compaction exist but require substantial hydrological data sets and are time consuming to calibrate. Land deformation can be measured using interferometric synthetic aperture radar (InSAR) and GPS, but the former is computationally expensive to estimate at scale and is subject …


Probability Distributions Of Particle Hop Distance And Travel Time Over Equilibrium Mobile Bedforms, Robert C. Mahon, Ashley C. Thomas, Suleyman Naqshband, Kate C. P. Leary, Brandon Mcelroy Jul 2020

Probability Distributions Of Particle Hop Distance And Travel Time Over Equilibrium Mobile Bedforms, Robert C. Mahon, Ashley C. Thomas, Suleyman Naqshband, Kate C. P. Leary, Brandon Mcelroy

Earth and Environmental Sciences Faculty Publications

The joint probability distribution of streamwise particle hop distance, lateral particle hop distance, and travel time constrains the relationships between topographic change and sediment transport at the granular scale. Previous studies have investigated the ensemble characteristics of particle motions over plane bed topography; however, it is unclear whether reported distributions remain valid when bedforms are present. Here, we present measurements of particle motion over bedform topography obtained in a laboratory flume and compare these to particle motions over plane bed topography with otherwise similar conditions. We find substantial differences in particle motion in the presence of bedforms that …


Improved Characterization Of Thin Bed And Low-Resistivity/Low-Contrast Hydrocarbon Reservoirs, Hasnan Hijaz Kamal Jul 2020

Improved Characterization Of Thin Bed And Low-Resistivity/Low-Contrast Hydrocarbon Reservoirs, Hasnan Hijaz Kamal

Student Works (2020-2029)

Thin-bed and low-resistivity/low-contrast (LRLC) reservoirs such tidal heterolithic deposits contain a significant amount of the global hydrocarbon reserves. However, due to millimetre-to-centimetre thin sandstone, forecasting hydrocarbon reserves and production are challenging. Producing hydrocarbon economically from heterolithic deposits in thin-bed reservoirs requires the characterisation of flow properties in thin beds for improved hydrocarbon reserves and production estimates. Sedimentology interpretation of the study area and reservoir in Malaysia shows that heterolithic deposits are part of tidal bars in a shallow marine environment with a large areal extent that suggests the substantial volume of heterolithic deposits which represent potential hydrocarbon reserves. Conventional Well …


Fayetteville And Imo Shales: Punctuated Upper Mississippian Shallowing Upward Sequence, Southern Ozark Region, Northern Arkansas, Joshua Stevens Jul 2020

Fayetteville And Imo Shales: Punctuated Upper Mississippian Shallowing Upward Sequence, Southern Ozark Region, Northern Arkansas, Joshua Stevens

Graduate Theses and Dissertations

The late Mississippian lithostratigraphic succession in the southern Ozark region, northern Arkansas, include, in ascending order, the Meramecan Moorefield Shale, Batesville Sandstone (with Hindsville Member); Chesterian Fayetteville Shale and Pitkin Limestone (with Imo Member). This interval is now interpreted as a single transgressive-regressive, unconformity-bounded, eustatic, third order cycle (Stevens and Manger, 2018). The Moorefield lowstand wedge is bound by a basal unconformity and succeeded by the transgressive Batesville Sandstone with its Hindsville Member. This succession reflects accretionary deposition along strike of the rising strand line, likely as a barrier island system, as its equivalents are shale (basinward) and limestone (laterally …