Post-Wildfire Recovery Of An Upland Oak-Pine Forest On The Cumberland Plateau, Kentucky, Usa, Devin E. Black, Zachary W. Poynter, Claudia A. Cotton, Suraj Upadhaya, David D. Taylor, Wendy Leuenberger, Beth A. Blankenship, Mary A. Arthur

Forestry and Natural Resources Faculty Publications

Background: Many forests within the southern Appalachian region, USA, have experienced decades of fire exclusion, contributing to regeneration challenges for species such as oaks (Quercus spp. L.) and pines (Pinus spp. L.), and threatening the maintenance of oak-dominated forests in the future. While the use of prescribed fire as a forest management tool is increasing within this region, there remains a lack of information on the potential role of wildfire. A wildfire within the Daniel Boone National Forest, Kentucky, USA, provided an opportunity to investigate how wildfire affected forest vegetation response.

Results: We examined the effects of fire …

Groundwater Level Response To The Wenchuan Earthquake Of May 2008, Anhua He, Ramesh Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

We have comprehensively analysed the co-seismic response of the groundwater levels of 280 wells in mainland China that were associated with the Wenchuan earthquake (Mw 7.9) that occurred on 12 May 2008. The observed co-seismic responses can be classified as step-like changes in 138 wells, variations in 69 wells and non-responses in 73 wells. After a quantitative analysis of spatial distribution, there was no spatially coherent signal found in the step-like changes (positive values indicate a step-like rise, and negative values indicate a step-like fall), even within 300 km of the epicenter. The amplitude and the phase shift of the …

Climate Evolution Across The Mid-Brunhes Transition, Aaron M. Barth, Peter U. Clark, Nicholas S. Bill, Feng He, Nicklas G. Pisias

School of Earth & Environment Departmental Research

The Mid-Brunhes Transition (MBT) began ∼ 430 ka with an increase in the amplitude of the 100 kyr climate cycles of the past 800 000 years. The MBT has been identified in ice-core records, which indicate interglaciations became warmer with higher atmospheric CO2 levels after the MBT, and benthic oxygen isotope (δ18O) records, which suggest that post-MBT interglaciations had higher sea levels and warmer temperatures than pre-MBT interglaciations. It remains unclear, however, whether the MBT was a globally synchronous phenomenon that included other components of the climate system. Here, we further characterize changes in the climate system across the MBT …

Geomorphology Of Shell Ridges And Their Effect On The Stabilization Of The Biloxi Marsh, East Louisiana, Frances R. Crawford

LSU New Orleans Theses and Dissertations

Extensive shell ridges frame the edges of marsh platforms in parts of the Biloxi Marsh of southeast Louisiana. The exact sources of the shells in these accumulations have not been clearly identified but the most likely source is a combination of shells from modern offshore and shells excavated from buried St. Bernard delta deposits. Larger or fetch-protected ridges remain stable through time, whereas ridges facing open water are more mobile, moving as much as 38 m inland from July 2017 to January 2018. Behind stable ridges, marsh platform biomass is relatively unaffected. When ridges are mobile, vegetation is smothered, leaving …

The Relationship Between The Phosphate And Structural Carbonate Fractionation Of Fallow Deer Bioapatite In Tooth Enamel, Holly Miller, Carolyn Chenery, Angela L. Lamb, Hilary Sloane, Ruth F. Carden, Levent Atici, Naomi Sykes

Anthropology Faculty Research

Rationale The species‐specific relationship between phosphate (δ18OP values) and structural carbonate (δ18OC values) oxygen isotope ratios has been established for several modern and fossil animal species but until now it has not been investigated in European fallow deer (Dama dama dama). This study describes the relationship between phosphate and structural carbonate bioapatite in tooth enamel of extant fallow deer, which will help us further understand the species' unique environmental and cultural history. Methods The oxygen isotope composition of phosphate (δ18OP value) and structural carbonate (δ18OC value) of hydroxylapatite was determined in 51 modern fallow deer tooth enamel samples from across …

Magmatic Response To Subduction Initiation: Part 1. Fore-Arc Basalts Of The Izu-Bonin Arc From Iodp Expedition 352, John W. Shervais, Mark Reagan, Emily A. Haugen, Renat R. Almeev, Julian A. Pearce, Julie Prytulak, Jeffrey G. Ryan, Scott A. Whattam, Marguerite Godard, Timothy Chapman, Hongyan Li, Walter Kurz, Wendy R. Nelson, Daniel Heaton, Maria Kirchenbaur, Kenji Shimizu, Tetsuya Sakuyama, Yibing Li, Scott K. Vetter

Geosciences Faculty Publications

The Izu-Bonin-Mariana (IBM) fore arc preserves igneous rock assemblages that formed during subduction initiation circa 52 Ma. International Ocean Discovery Program (IODP) Expedition 352 cored four sites in the fore arc near the Ogasawara Plateau in order to document the magmatic response to subduction initiation and the physical, petrologic, and chemical stratigraphy of a nascent subduction zone. Two of these sites (U1440 and U1441) are underlain by fore-arc basalt (FAB). FABs have mid-ocean ridge basalt (MORB)-like compositions, however, FAB are consistently lower in the high-field strength elements (TiO2, P2O5, Zr) and Ni compared to MORB, with Na2O at the low …

Mercury In Big Cypress Bayou And Caddo Lake Watersheds In Marion And Harrison Counties Texas, Joseph Watkins

Electronic Theses and Dissertations

Caddo Lake has been included on the Texas Commission on Environmental Quality 303(d) list for impairment due to mercury (Hg) content since 1996. One of the primary tributaries, Big Cypress Bayou, flows across Eocene-aged rocks and sediments associated with the Wilcox Group; the Wilcox is of interest because it contains lignite coal, which has a direct link to mercury. Previous research has focused on dry deposition from fossil fuel combustion as the primary source of mercury but has not addressed the potential watershed contribution to mercury concentrations in Caddo Lake.

Big Cypress Bayou flows through Harrison and Marion counties in …

Delineation Of Karst Potential Using Lidar And Gis Analyses, Fort Hood Military Installation, Texas, Colby Reece

Electronic Theses and Dissertations

ABSTRACT

Traditional karst surveys require extensive field investigations to completely characterize large areas. They are often time-consuming, requiring up to several years to collect and categorize data. Bias is given to areas that are most easily accessible and false negatives are common. The implementation of geographic information systems (GIS) has aided in the aggregation and standardization of karst data; however, these systems have also been used to develop terrain models that allow the user to remotely delineate sinkholes and other surficial features. The Fort Hood Military Installation is a karst landscape that has been altered significantly for use in military …

Monitoring The Impact Of Groundwater Pumping On Infrastructure Using Geographic Information System (Gis) And Persistent Scatterer Interferometry (Psi), Kirsten Deprekel, El Hachemi Bouali, Thomas Oommen

Department of Geological and Mining Engineering and Sciences Publications

Transportation infrastructure is critical for the advancement of society. Bridges are vital for an efficient transportation network. Bridges across the world undergo variable deformation/displacement due to the Earth’s dynamic processes. This displacement is caused by ground motion, which occurs from many natural and anthropogenic events. Events causing deformation include temperature fluctuation, subsidence, landslides, earthquakes, water/sea level variation, subsurface resource extraction, etc. Continual deformation may cause bridge failure, putting civilians at risk, if not managed properly. Monitoring bridge displacement, large and small, provides evidence of the state and health of the bridge. Traditionally, bridge monitoring has been executed through on-site surveys. …

Prokaryotic Diversity And Aqueous Geochemistry Of Subsurface Environments Of The Death Valley Regional Flow System, Joshua David Sackett

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation summarizes over four years of effort towards the completion of a Ph.D. in Biological Sciences. The work presented in this document covers a broad range of topics, but a central unifying theme is prokaryotic life in the continental subsurface. The work presented in each chapter relied heavily on cultivation-independent methods for assessing prokaryotic communities, including prokaryotic community structure reconstruction from high-throughput sequencing of 16S rRNA gene libraries and single-cell genome analysis of novel uncultivated bacteria.

Chapter 2 examines the aqueous geochemistry and prokaryotic diversity of Devils Hole, a cavernous limnocrene and sole natural habitat for the critically endangered …

Petrogenesis Of Enriched And Intermediate Poikilitic Shergottites: From Magmatic Source To Emplacement, Rachel Rahib

UNLV Theses, Dissertations, Professional Papers, and Capstones

Poikilitic shergottites, making up >20% of martian meteorites, likely represent a significant composition of the martian crust, as intrusive gabbroic rocks. To further constrain petrogenetic relationships amongst enriched and intermediate poikilitic shergottites, we utilize bulk rock trace element compositions, mineral major element compositions, phosphorus maps of olivine grains, oxygen fugacity (ƒO2) values, subsolidus equilibration temperatures, and quantitative textural analyses, of the most comprehensive suite of poikilitic shergottites yet (11 samples), including three newly recovered samples (Northwest Africa [NWA] 11065, NWA 11043, NWA 10961). Although petrographically light rare earth element (LREE) enriched and intermediate poikilitic shergottites are similar, distinct LREE abundances …

Mineralogy, Petrology, And Geochemistry Of The Unique Silica-Rich Ungrouped Achondrite Northwest Africa 11575, Mya Ann Habermann

Earth and Planetary Sciences ETDs

We report here on a unique, newly discovered, silica-rich ungrouped achondrite Northwest Africa 11575 (NWA 11575). NWA 11575 is one of four known silica-rich ungrouped achondrites, presenting evidence for igneous processes resulting in evolved compositions early in the history of the solar system. It is unique from the other silica-rich ungrouped achondrites in that it has pyroxene compositional trends matching those of lunar samples and martian meteorites; contains quartz and potassium feldspar; and contains oxygen, hydrogen, and chromium isotopes that are similar to those of LL chondrites. Together, these four silica-rich ungrouped achondrites provide evidence for evolved compositions resulting from …

Insights Into Fluid-Rock Interactions On The Cv3 Carbonaceous Chondrite Asteroid: The Complex Record In The Allende-Like Cv3 Chondrite, Nwa 2364., Jessica Marie Johnson

Earth and Planetary Sciences ETDs

The two subgroups of the CV3 chondrites, oxidized and reduced, contain primitive solar system materials that provide many insights into early solar system processes. Both subgroups record significant evidence of secondary alteration that has modified their primary characteristics. In this work, we have studied the petrography, mineralogy, and oxygen isotopic composition of the NWA 2364 CV3_OxA chondrite and a large lithic inclusion using SEM, electron microprobe, FIB/TEM, and laser fluorination oxygen isotope analyses in order to characterize their alteration histories in detail. The NWA 2364 host and lithic inclusion consist of chondrules, Calcium-Aluminum-rich Inclusions (CAIs), and fine-grained matrix. In …

The Ages2 (Awards For Geochronology Student Research 2) Program: Supporting Community Geochronology Needs And Interdisciplinary Science, Rebecca M. Flowers, J. Ramón Arrowsmith, Vicki Mcconnell, James R. Metcalf, Tammy M. Rittenour, Blair Schoene

Geosciences Faculty Publications

Geochronology is essential in the geosciences. It is used to resolve the durations and rates of earth processes, as well as test causative relationships among events. Such data are increasingly required to conduct cutting-edge, transformative, earth-science research. The growing need for geochronology is accompanied by strong demand to enhance the ability of labs to meet this pressure and to increase community awareness of how these data are produced and interpreted. For example, a 2015 National Science Foundation (NSF) report on opportunities and challenges for U.S. geochronology research noted: "While there has never been a time when users have had greater …

Widespread, Prolonged Microbial Limestone Deposition And Large, Rapid Sulfur Isotope Excursions: A New Perspective On The Early Triassic From The Western U.S., Brad M. Jeffrey

Earth and Planetary Sciences ETDs

The Early Triassic records a ~5 My period of marine biological recovery following the end-Permian mass extinction (EPME, ~252 My). Global oceans were characterized by warm sea-surface temperatures (SSTs), widespread anoxia, and major perturbations to the carbon cycle, the collective result of repeated massive Siberian Traps eruptions and associated global climate feedbacks. Globally widespread microbial deposits (stromatolites, thrombolites) developed in shallow marine environments. Several marine isotope records (C, O, S, U) indicate repeated, large-magnitude shifts related to paleoceanographic events during the recovery of marine ecosystems following the EPME.

Chapter 1 describes and interprets a widespread (~400 km along strike) Smithian …

Designing A Protected Area To Safeguard Imperiled Species From Urbanization, Stephanie S. Romanach, Brad Stith, Fred A. Johnson

United States Geological Survey: Staff Publications

Reserve design is a process that can address ecological, social, and political factors to identify parcels of land needed to sustain wildlife populations and other natural resources. Acquisition of parcels for a large terrestrial reserve is difficult because it typically occurs over a long timeframe and thus invokes consideration of future conditions such as climate and urbanization changes. In central Florida, the U.S. government has authorized a new protected area, the Everglades Headwaters National Wildlife Refuge. The new refuge will host important threatened and endangered species and habitats, and will be located to allow for species adaptation from climate change …

Discovery Of Paleotsunami Deposits Along Eastern Sunda Arc: Potential For Megathrust Earthquakes In Bali, Hanif Ibadurrahman Sulaeman

Theses and Dissertations

Several laterally extensive candidate tsunami deposits are preserved along coastlines facing the eastern Java Trench, indicating it has experienced mega-thrust earthquakes in the past. We investigated 37 coastal sites in Bali, Lombok, Sumba and Timor islands, many of which preserve course sand and pebble layers that overlie sharp basal contacts with scour marks into the mud, fine upward in grain size, and have bimodal grain size distributions. Other unique features are the common occurrence of marine fossils and concentrations of heavy minerals. The occurrence of these high-energy deposits interlayered with clay-rich units indicates the coarse clastics are anomalous because they …

Diamond Intracrystalline Stable Isotope Chemical Image Analysis By Time-Of-Flight Secondary Ionization Mass Spectrometery, Tyler J. Sundell

Graduate Theses/Dissertations

The chemical resistance of diamond allows in-situ study of the diamond source regions. For a majority of gem quality diamonds, this source region is the sublithospheric mantle keel of a cratonic nuclei. Through analysis of stable isotopes, radiogenic isotopes and trace elements, diamond geochemical analyses can define chemical fluxes in the mantle keel. However, such studies require multiple methodologies for each chemical suite, high spatial resolution and analytical precision. Here, I evaluate Time-of-Flight Secondary Ionization Mass Spectrometer (ToF-SIMS) as an alternative method for diamond geochemical analyses. ToF-SIMS analysis can perform in cation and anion mode to measure the entire periodic …

The Influence Of Mechanical Stratigraphy On Thrust-Ramp Nucleation And Propagation Of Thrust Faults, Sarah S. Wigginton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Our current understanding of thrust fault kinematics predicts that thrust faults nucleate on low angle, weak surfaces before they propagate upward and forms a higher angle ramp. While this classic kinematic and geometric model serves well in some settings, it does not fully consider the observations of footwall deformation beneath some thrust faults. We examine an alternative end-member model of thrust fault formation called “ramp-first” fault formation. This model hypothesizes that in mechanically layered rocks, thrust ramps nucleate in the structurally strong units, and that faults can propagate both upward and downward into weaker units forming folds at both fault …

Receiver Function Investigations Of Seismic Anisotropy Layering Beneath Southern California, Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Jianguo Song, Weiwei Ding, Yinxia Fang, Aiguo Ruan, Jiabiao Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Seismic azimuthal anisotropy characterized by shear wave splitting analyses using tele seismic XKS phases (including SKS, SKKS, and PKS) is widely employed to constrain the deformation field in the Earth's crust and mantle. Due to the near-vertical incidence of the XKS arrivals, the resulting splitting parameters (fast polarization orientations and splitting times) have an excellent horizontal but poor vertical resolution, resulting in considerable ambiguities in the geodynamic interpretation of the measurements. Here we use P-to-S converted phases from the Moho and the 410- (d410) and 660-km (d660) discontinuities to investigate anisotropy layering beneath Southern California. Similarities between the resulting splitting …

Exploring Potential Water-Ice Occurrence On Asteroid 4 Vesta Using Orbital Radar Observations By The Dawn Mission, Elizabeth M. Palmer

Dissertations

Airless, differentiated planetesimals in the inner solar system were presumed to have been depleted of most of their initial volatile content during formation. However, water-ice has been discovered at the lunar poles (Li et al., 2018), is inferred to exist in polar craters on Mercury (e.g., Butler, Slade & Muhleman, 1993, and suggested to survive beneath the dusty regolith of objects in the main asteroid belt if buried at sufficient depths—at least one meter for small-bodies in the outer main-belt (Schorghofer, 2008). Hence, the study of volatile occurrence, past or present, on airless, desiccated small-bodies provides insights into the timing, …

Assessing Land Deformation And Sea Encroachment In The Nile Delta: A Radar Interferometric And Modeling Approach, Esayas Gebrekidan Gebremichael

Dissertations

Many of the deltas of the world are experiencing land deformation, subsidence or uplift of landmass, due to natural or anthropogenic causes, or a combination of both processes and causes. These deltaic settings are densely populated and border some of our world’s largest water bodies (oceans and seas). The land deformation, especially the subsidence component, when combined with the climate change-induced sea level rise, coastal erosion, and other anthropogenic drivers, will undoubtedly impact the population and economy of coastal areas of deltas. For the Nile Delta of Egypt, the land deformation processes and the factors that control the deformation processes …

Physical And Chemical Controls On Suffosion Development In Gypsic Soil, Culberson County, Texas, Jonah Morris

Electronic Theses and Dissertations

In the Gypsum Plain, suffosion processes have encouraged road failure through dissolution and transport of gypsic soils; however, no prior research has been conducted within the Delaware Basin in regard to these processes. These phenomena were evaluated in both field and laboratory settings in order to assess the parameters of suffosion development associated with Ranch to Market (RM) 652 in Culberson County, Texas, where infrastructure extends across Castile and Rustler strata. Field studies simulated surficial ponding in various gypsic soils and correlated suffosion potential with soil composition and thickness. Soluble fractions of gypsic soils were delineated through geochemical analyses, further …

Depositional Environment And Facies Analyses Of The Owl Mountain Province, Fort Hood Military Installation, Bell And Coryell Counties, Texas, Jacob Meinerts

Electronic Theses and Dissertations

The Owl Mountain Province is a plateaued, karst landscape located in the eastern section of the Fort Hood Military Installation and is characterized by Lower Cretaceous Fredericksburg Group carbonates. The topography is capped by thick sequences of the Edwards limestone; steep scarps and incised valleys along the edges of the plateaus host inter-fingering outcrops of the Edwards and Comanche Peak limestones, and the lower valleys are covered by alluvial sediments and intermittent outcrops of the Walnut Clay. These formations were deposited to the north and west of the main Edwards trend, and are thought to be part of a series …

An Outcrop Based Study Of The Weches Formation In Sabine County, Texas: Investigating Its Unconventional Resource Potential Through The Study Of Stratigraphy, Sedimentology, Petrology, And Geochemistry, Talban Kantala

Electronic Theses and Dissertations

Fresh Weches Formation (Middle Eocene) exposures found in aggregate quarries in Sabine County, Texas, were sampled, measured, and logged with gamma-ray spectrometry (GRS). Sedimentology and petrology characteristics of Weches samples were analyzed through thin section, scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and GRS Th/K ratios analyses. The source rock quality of the Weches was evaluated with geochemical techniques involving total organic carbon (TOC), Rock-Eval pyrolysis, and GRS Th/U ratios.

The Weches, in the study area, is 27.4 meters thick, and delineated into three major stratigraphic facies: an upper marginal marine prodeltaic facies (Therrill Member) comprised of silty claystones and …

Evaluating Stable Isotope And Geochronologic Techniques For Paleoclimate Reconstruction: Case Study Of The Santa Cruz Formation, Argentina, Robin B. Trayler

Boise State University Theses and Dissertations

Stable isotope analysis has become the method of choice for many studies investigating the paleoecology and paleoclimate of fossil mammal faunas. While organic tissues (collagen, keratins, proteins) persist for < 10⁵ years highly mineralized tooth enamel is resistant to alteration and degradation and faithfully preserves its isotopic composition for millions (> 10⁶) years. Reconstructing past climates from these records relies on both understanding both micro-scale mechanisms of isotope incorporation into individual teeth, and macro-scale changes in isotope compositions over hundreds of thousands or millions of years. In this dissertation I address three questions.

First, how does the geometry and …

Predicted Deepwater Bathymetry From Satellite Altimetry: Non-Fourier Transform Alternatives, Maxsimo Salazar

Dissertations

Robert Parker (1972) demonstrated the effectiveness of Fourier Transforms (FT) to compute gravitational potential anomalies caused by uneven, non-uniform layers of material. This important calculation relates the gravitational potential anomaly to sea-floor topography. As outlined by Sandwell and Smith (1997), a six-step procedure, utilizing the FT, then demonstrated how satellite altimetry measurements of marine geoid height are inverted into seafloor topography. However, FTs are not local in space and produce Gibb’s phenomenon around discontinuities. Seafloor features exhibit spatial locality and features such as seamounts and ridges often have sharp inclines. Initial tests compared the windowed-FT to wavelets in reconstruction of …

Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis

Master's Theses

Coastal systems in the Gulf of Mexico are threatened to reduced sediment supply, storm impacts and relative sea level rise (RSLR). The geologic record can provide insights of geomorphic threshold crossings (formation, progradation, transgression, destruction) to these forcing mechanisms to predict future barrier evolution to climate change. The stratigraphic framework and antecedent topography directly influence coastal evolution over geologic timescales. This study synthesizes ~2100km of geophysical data, 700+ sediment cores, and 63 radiocarbon dates to regionally map two sequence boundaries, multiple ravinement surfaces and fourteen depositional facies. One marine isotope stage (MIS) 6 valley’s fill provided up to 300 x10 …

Holocene Formation And Evolution Of Horn Island, Mississippi, Usa, Nina Gal

Master's Theses

Horn Island, one of the most stable barriers along the Mississippi-Alabama chain, provides critical habitat, helps regulate estuarine conditions in the Mississippi Sound, and reduces wave energy and storm surge for the mainland. This study integrates 2,200 km of high-resolution geophysics, 35 sediment cores, and 15 radiocarbon ages to better understand the formation and evolution of the island in response to sea-level rise, storms, and antecedent geology. The Biloxi and Pascagoula incised valleys converge at Horn Island and have played a profound role in the evolution of the system. Within the incised valleys, numerous shallow paleochannels between 4 and 9 …

Margaret White Springs Recharge Study, Buffalo National River, North-Central Arkansas, Usa, Ashlon Elizabeth Leonard

Graduate Theses and Dissertations

Margaret White Springs (MWS) is one of the largest springs in the middle section of the Buffalo National River (BNR) and contributes several tens of cubic feet per second of flow to river discharge on average, yet the source of the water has not been fully studied or documented. The spring is located approximately 4 miles downstream from Robertson Hole, a losing reach of the river. At Robertson Hole the river loses a significant amount of flow to groundwater, which during the dry season (summer) can be as much as 100%. Flow in the main channel is re-established at MWS; …