Digital Commons Network^™

Crustal Azimuthal Anisotropy Beneath The Southeastern Tibetan Plateau And Its Geodynamic Implications, Tuo Zheng, Zhifeng Ding, Jieyuan Ning, Lijun Chang, Xingchen Wang, Fansheng Kong, Kelly H. Liu, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The fast orientation and magnitude of crustal azimuthal anisotropy beneath the southeastern Tibetan Plateau and adjacent areas are measured by analyzing the sinusoidal moveout of the P to S converted phase from the Moho. Beneath the tectonically active plateau, the mean magnitude is 0.48 ±Â 0.13 s, which is about twice as large as that observed in the stable Sichuan Basin (0.23 ±Â 0.10 s). The two areas are separated by the Longmenshan fault zone, a zone of devastating earthquakes including the 12 May 2008 M_W 7.9 Wenchuan earthquake. Fault orthogonal fast orientations observed in the southern Longmenshan fault …

When The Well Runs Dry: Why Water-Rich States Need To Prepare For Climate Change And Protect Their Groundwater, Danielle Takacs

William & Mary Environmental Law and Policy Review

It may seem surprising to see such concern over groundwater usage in a state like Wisconsin. While known for its dairy and cheese production, Wisconsin is first in the nation for producing snap beans and cranberries. Agriculture contributes $88.3 billion annually to Wisconsin’s economy alone. In addition to bordering two of the Great Lakes, Lake Michigan and Lake Superior, Wisconsin boasts that it is home to about 15,000 lakes. And this does not include the numerous rivers and streams throughout the state. These facts alone may make Wisconsin seem an unlikely place for disputes over groundwater, as water seems to …

Middle Permian (Late Guadalupian) Back-Reef Carbonate Of Panther Canyon, Apache Mountains, Trans-Pecos Texas, Joshua Caleb Moore

Earth & Environmental Sciences Theses - Archive

In the Apache Mountains of West Texas, Middle Permian (Guadalupian) strata a portion of the Delaware Basin part of the Capitan Reef is well exposed in many canyons that cut through the northern escarpment in the eastern part of the mountains. In Panther Canyon, the massive part of the Capitan Reef is well exposed and overlain by a stratigraphic sequence of lagoonal carbonate deposits referred to the Yates and Tansill Formations. At the entrance to Panther Canyon, two sections of these stratified carbonate rocks have been measured and described: the PC7 section, 31.8 meters thick, with eight distinct packages and …

Sequence Stratigraphy Of Campanian-Maastrichtian Strata In Eastern Alabama, David Simmons

Master's Theses

Eastern Alabama is an area of interest due to the transition from the Gulf Coastal Plain to the Atlantic Coastal Plain. Coastal Plain investigations have been sparse compared to research conducted in the oil rich areas down dip in the Gulf of Mexico. A sequence stratigraphic framework using the T-R cycle methodology of Embry (2002) has been established by integrating surface and subsurface lithologic data with biostratigraphic zonations into Petra ®. High sedimentation from the ancestral Chattahoochee River and lower relative sea-level formed an additional depositional sequence within the Santonian-Campanian aged Blufftown Formation in eastern Alabama. The sequence is approximately …

Unconfined Hypogene Evaporite Karst: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford, Jon T. Ehrhart, Adam F. Majzoub, Jessica M. Shields, Wesley A. Brown

International Journal of Speleology

Diverse karst phenomena occur throughout the Gypsum Plain where the Castile Formation crops out over ~1800 km² in West Texas and southeastern New Mexico. Hypergene karst is extensive and widespread, while traditional hypogene karst manifestations (both caves and intrastratal dissolution) occur in high frequency in the western outcrop region where surface denudation has been the greatest so as to induce surficial breaching. Unconfined hypogene karst occurrences have been recently identified, including two general variations: 1) artesian-like discharge features; and 2) venting structures. Artesian-like discharge features arise at surficially-breached hypogene caves and through high permeability regions on the margins of …

Spar Caves As Fossil Hydrothermal Systems: Timing And Origin Of Ore Deposits In The Delaware Basin And Guadalupe Mountains, New Mexico And Texas, Usa, David D. Decker, Victor J. Polyak, Yemane Asmerom

International Journal of Speleology

Studies of sulfuric acid hypogene speleogenesis have contributed significantly to understanding the history of the Guadalupe Mountains of southeast New Mexico and west Texas for at least the past 12 Ma. A recently published hypothesis of supercritical CO₂ spar cave genesis provides information that constrains the timing of the start of uplift to between 27 and 16 Ma, and helps to explain landscape evolution of this region for the last 185 Ma. This new speleogenetic model is summarized here and shows that U-Pb dating of crystals from different spar caves reveal different ages, and that a majority of the …

Detection Of Bedrock Fractures And Joints Beneath Cover: Geophysical Approaches To An Engineering Geology Problem, Muthanna Yousif Yaqoob Aldiney

Dissertations

This research used geophysical methods to detect the presence of sub-vertical failure planes, their direction(s), and their frequency in bedrock beneath soil or glacial drift overburden. Azimuthal measurements using the seismic, electrical resistivity (ER), and electromagnetic conductivity were made to evaluate which techniques might provide the best indication of the bedrock joints, faults, or shear zones. Measurements were made at multiple sites near each of three locations: Jackson, Alpena, and Grand Ledge, Michigan. The first two are former limestone quarries and the third is underlain by sandstone. Seismic measurements began with one or two linear refraction spreads, used to establish …

Structural Evolution And Regional Implications Of The Arrowhead Mine Fault Within The Pahranagat Shear Zone, Nevada, Usa, Michael Dennis Evans

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Basin and Range province is characterized by normal faults associated with

extension, but the occurrence of strike-slip faults and the seismic hazard accompanying

them is less understood. One major strike-slip zone, the Pahranagat shear zone (PSZ),

lies in Lincoln County, Nevada and within the boundary zone between northern Basin

and Range (NBR) and central Basin and Range (CBR) sub-provinces. The PSZ is a 20-

25 km long zone of Cenozoic left-lateral faults. The Arrowhead Mine Fault (AMF) is one

of the three major faults in the PSZ. The western AMF and the faults that surround and

abut it are …

Preliminary Sedimentology And Stratigraphy Of The Enigmatic Middle Lake Beds Succession (Pleistocene?) In The Rukwa Rift Basin, Tanzania, Cassy Mtelela

Tanzania Journal of Science

This paper presents sedimentology and stratigraphic overview of a series of previously unrecognized lithostratigraphic unit in the Rukwa Rift Basin, Tanzania. Based on the cross-cutting relationship and pilot detrital zircon geochronology, these isolated, enigmatic strata are herein informally termed the middle Lake Beds (mLB). Facies analysis reveals that the mLB units were deposited within a complex array of depositional environments, ranging from alluvial to fluvial channels, floodplains and shallow lakes.  The mLB are characterised herein as isolated outcrop exposures with uncertain age relationships, but which can be divided into five distinctive lithostratigraphic units herein identified as informal members (A-E). These …

Characterization Of Metamorphic Zones In The Tennessee Blue Ridge Using Gis And Digital Imaging Processing, Hayley Beitel

Honors Theses

The origin of metamorphic zones of the Blue Ridge is attributed to metamorphic events that affected sedimentary rocks of debated age, leading the topic to be controversial and continuously studied. The present study seeks to refine the metamorphic isograds of the Tennessee Blue Ridge based on Barrovian index minerals in pelitic rocks and the texture patterns these pelitic rocks present. Methods used in the present study are supported by conventional petrography, powder X-ray diffraction, and by GIS and digital image processing. Metamorphic isograds in the Blue Ridge have been determined mainly by identification of index minerals using a polarizing petrographic …

Fluoride Occurrence In Domestic Water Supply Sources In Tanzania: A Case Of Meru District Arusha Region, Godfrey Mbabaye, Rwaichi Minja, Felix Mtalo, Isack , Legonda, Godfrey Mkongo

Tanzania Journal of Science

Surface and ground water are the major sources of water supply in Meru district. Most of the people in Meru rural areas depend on surface water in rivers and ground water shallow and deep wells and springs for house hold activities. The presence of fluoride in high concentrations in drinking water or cooking water causes severe health problems to the people. Distribution of fluoride concentrations in Meru district domestic water sources was studied by referencing the location of water sources using Extrex 20 garmin hand held GPS instrument. Fluoride concentrations were measured using Metrohm Ag/AgCl reference electrode connected to a …

Microtextural Studies Of Feldspar In Ordinary Chondrites, Jonathan A. Lewis

Earth and Planetary Sciences ETDs

Ordinary chondrites contain an important record of events that took place during the earliest period of solar system evolution. These include primary processes, such as chondrule formation, and secondary processes, those that affected asteroids after accretion and modified primary components. Secondary processes include aqueous alteration, thermal metamorphism, and shock effects from impact events. Secondary minerals can provide insight into the chemical and physical conditions that affected their parent asteroids. Feldspar is known to be a secondary mineral that crystallized during thermal metamorphism. The goal of this work is to use the formation and evolution of feldspar to elucidate the conditions …

Mapping And Interpreting The Glacial Geology Of Pictured Rocks National Lakeshore, Michigan, Sarah M. Vandermeer

Dissertations

Pictured Rocks National Lakeshore is among the most popular parks in Michigan, yet prior to this study, it was the only National Park that lacked a detailed surficial geology map characterizing the distribution of sediments and landforms. Additionally, much of the landscape remained unexplored. These factors prevented thorough interpretations of landscape development and evolution. This research aims to map and further explore the relationship of glacial sediments and landforms throughout Pictured Rocks to refine and expand the current understanding of glacial events that shaped this landscape.

A new, detailed (1:24,000-scale) surficial geology map of the ten 7.5-minute quadrangles that contain …

Sediment And Plant Dynamics In A Degrading Coastal Louisiana Landscape, Glenn Michael. Suir

LSU Doctoral Dissertations

Alterations to Louisiana’s river systems and local hydrology have resulted in reduced freshwater, sediment, and nutrient inputs into wetland landscapes, causing significant negative impacts on marsh productivity and stability. To combat these losses many restoration projects have been constructed or planned throughout coastal Louisiana. Typical goals of wetland restoration efforts are to conserve, create, or enhance wetland form, and to achieve wetland function that approaches natural conditions. Failure to adequately maintain wetland elevation and hydrology can have serious implications on sedimentation and vegetation processes, which significantly reduces the likelihood of reaching structural and functional targets. Measures of wetland condition have …

Global Seawater Redox Trends During The Late Devonian Mass Extinction Detected Using U Isotopes Of Marine Carbonates, David Allen White

Earth and Planetary Sciences ETDs

The Late Devonian extinction ranks as one of the ‘big five’ Phanerozoic extinctions affecting up to 80% of marine species and occurred during five distinct pulses spanning /or widespread marine anoxia. We test the marine anoxia hypothesis by analyzing uranium isotopes (δ²³⁸U) across a ~7 My interval of well-dated Upper Devonian marine carbonates from the Devil’s Gate Limestone in Nevada, USA.

The measured δ²³⁸U curve shows no co-variation with local anoxic facies, water-depth dependent facies changes, redox-sensitive metals, TOC, or diagnostic elemental ratios indicating the δ²³⁸U curve was not controlled by local depositional or …

Unconfined Hypogene Evaporite Karst: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford, Jon T. Ehrhart, Adam F. Majzoub, Jessica M. Shields, Wesley A. Brown

Faculty Publications

Diverse karst phenomena occur throughout the Gypsum Plain where the Castile Formation crops out over ~1800 km² in West Texas and southeastern New Mexico. Hypergene karst is extensive and widespread, while traditional hypogene karst manifestations (both caves and intrastratal dissolution) occur in high frequency in the western outcrop region where surface denudation has been the greatest so as to induce surficial breaching. Unconfined hypogene karst occurrences have been recently identified, including two general variations: 1) artesian-like discharge features; and 2) venting structures. Artesian-like discharge features arise at surficially-breached hypogene caves and through high permeability regions on the margins of …

How To Efficiently Compute Ranges Over A Difference Between Boxes, With Applications To Underwater Localization, Luc Jaulin, Martine Ceberio, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

When using underwater autonomous vehicles, it is important to localize them. Underwater localization is very approximate. As a result, instead of a single location x, we get a set X of possible locations of a vehicle. Based on this set of possible locations, we need to find the range of possible values of the corresponding objective function f(x). For missions on the ocean floor, it is beneficial to take into account that the vehicle is in the water, i.e., that the location of this vehicle is not in a set X' describing the under-floor matter. Thus, the actual set of …

Reconstructing The Sedimentary Evolution Of The Miocene Aksu Basin Based On Fan Delta Development (Eastern Mediterranean-Turkey), Serkan Üner, Erman Özsayin, Ramazan Kadi̇r Di̇ri̇k, Tahsi̇n Atti̇la Çi̇ner, Mustafa Karabiyikoğlu

Turkish Journal of Earth Sciences

The Aksu Basin in southern Turkey is dominantly represented by an alluvial fan and five fan deltas (FDs) developed along the tectonically controlled margins of the basin during the Miocene. Four alternating compressional and tensional tectonic phases have influenced the basin since its formation. Strong tectonic movements caused high sedimentation rates and progradation of large debris-flow and mass-flow dominated FDs. Here we describe two FDs (the Karadağ and Kargı FDs) in detail. The Karadağ FD began to develop under the control of a compressional regime and continued the evolution under a tensional regime. The same tensional regime caused the separation …

Resistivity Inversion Of Transversely Isotropic Media, Ertan Pekşen, Türker Yas

Turkish Journal of Earth Sciences

In this paper, we have suggested a finite difference algorithm for resistivity forward and inverse modeling with electrically anisotropic media in applied geophysics. Electrical anisotropy affects the surface measurement in a fashion that may make interpretation erroneous. This means that the resistivity section obtained by an inversion method that does not incorporate electrical anisotropy gives the wrong subsurface structure. We used a classical multielectrode dataset of a profile for estimating not only horizontal but vertical resistivity as well. Thus, the electrical anisotropy can be calculated. Finally, the finite difference mesh can be corrected by using the estimated anisotropic coefficient. The …

Palaeontological Evidence And Sedimentary Facies In A Lower Miocene (Aquitanian) Succession From The Bingöl Minibasin (Sivas Basin), Central Anatolia, Mehmet Serkan Akki̇raz, Özgen Kangal, Nazi̇re Özgen Erdem, Yeşi̇m Büyükmeri̇ç, Ci̇han Doğruöz

Turkish Journal of Earth Sciences

The results of palaeontological (palynological and mollusc) and sedimentological analyses of the lower Miocene deposits from the Bingöl minibasin, a part of the Sivas Basin, are exhibited to define the vertical shifts in sedimentation environments and plant covers, linking to eustasy. The presence of index species Corbulomya (Lentidium) aquitanica suggests an Aquitanian age for the studied succession, which can be divided into three informal units: a lower unit, a middle unit, and an upper unit. Fine-grained sediments of the lower unit were deposited in a low sea-level setting due to high quantities of terrestrial palynomorphs. This unit is overlain by …

Supercycle In Great Earthquake Recurrence Along The Japan Trench Over The Last 4000 Years, Kazuko Usami, Ken Ikehara, Toshiya Kanamatsu, Cecilia M. Mchugh

Publications and Research

On the landward slope of the Japan Trench, the mid-slope terrace (MST) is located at a depth of 4000–6000 m. Two piston cores from the MST were analyzed to assess the applicability of the MST for turbidite paleoseismology and to find out reliable recurrence record of the great earthquakes along the Japan Trench. The cores have preserved records of ~ 12 seismo-turbidites (event deposits) during the last 4000 years. In the upper parts of the two cores, only the following earthquakes (magnitude M ~ 8 and larger) were clearly recorded: the 2011 Tohoku, the 1896 Sanriku, the 1454 Kyotoku, and …

Geophysical Investigations Of Southcentral Alaska, Felix Dziedzorm Ziwu

Open Access Theses & Dissertations

The Castle Mountain Fault (CMF) is the closest (<50 km) active fault to Anchorage, Alaska and is known to be capable of producing earthquakes of magnitude 7.0 â?? 7.1. While several mapping and trenching studies have been conducted along the CMF, geophysical investigations along the fault zone have been limited. We use over 700 recently collected, closely spaced gravity observations, in addition to existing regional gravity, aeromagnetic, seismic reflection, well log data, and geologic information, to develop new 2D models of the deeper structure of the CMF system. We developed four 2D integrated forward models across the Castle Mountain Fault. These models indicate differences between the western and eastern segments of the Castle Mountain Fault. The models show a thick sequence of Tertiary to Mesozoic sediments overlying the Peninsular terrane basement at varying depths within the area. We identified two main intrusive granitic rocks based on the varying susceptibilities. These granitic rocks share a possible fault contact with the Mesozoic sedimentary rocks. The model also shows that the CMF cuts through the Mesozoic sediments at depth. These rocks can create strong coupling along the fault and with the decreasing eastward angle of subduction, it is highly for fluid migration to the eastern edge of the subducting Yakutat microplate. Seismic events plotted along the profiles supports the Holocene motion along the western CMF (WCMF) and indicates a deeper extent of the CMF into the crust. The eastern CMF shows high rate of deformation based on the structures associated with the Mesozoic rocks.

Determing Fault Location Within An Active Rift Basin Using Gravity Analysis To Determine Fault Movemnet And Effect On Water Recharge, Mark Andrew Ornelas

Open Access Theses & Dissertations

The growth of the El Paso, TX and Ciudad Juárez, Chihuahua, metropolitan area has increased reliance of groundwater pumping from the Hueco Bolson. With growing demands for water and recharge of the bolson not occurring at a fast enough rate, water storage within the bolson is beginning to diminish. My study focuses on locating and understanding how faults interact with water flow into the basin and how they aid in storing water on the northwestern side of the bolson. Previous studies in the northernmost part of my study area have delineated a series of faults that predominantly trend northwest-southeast. In …

Whose Lands? Which Public?: The Shape Of Public-Lands Law And Trump's National Monument Proclamations, Jedediah Britton-Purdy

Faculty Scholarship

President Trump issued a proclamation in December 2017 purporting to remove two million acres in southern Utah from national monument status, radically shrinking the Grand-Staircase Escalante National Monument and splitting the Bears Ears National Monument into two residual protected areas. Whether the President has the power to revise or revoke existing monuments under the Antiquities Act, which creates the national monument system, is a new question of law for a 112-year-old statute that has been used by Presidents from Theodore Roosevelt to Barack Obama to protect roughly fifteen million acres of federal land and hundreds of millions of marine acres. …

An Integrated Machine Learning Geological Field Tool In The Age Of Big Data And Drones, Guillermo Vargas

Open Access Theses & Dissertations

Unmanned aerial vehicles (UAVs) and machine learning are relatively new research tools in the geosciences that can be used to collect and analyze large data sets rapidly. We combine the power of rapid data collection using unmanned aerial vehicles with machine learning algorithms to develop a field-based system to identify targeted geological features. For data collection, we have used a commercial-grade UAV which carried visible-wavelength and multispectral (visible- infrared) cameras. We analyzed the data with machine learning and machine vision algorithms that can classify rock units exposed in a field area. We have identified algorithms that in previous literature have …

The Blurred Line Between Photic And Aphotic Environments: A Large Mexican Cave With Almost No Dark Zone, Luis M. Mejía-Ortíz, Tanja Pipan, David C. Culver, Peter Sprouse

International Journal of Speleology

Sistema Muévelo Rico is a 1.2 km long cave in Quintana Roo, less than 2 km from the Caribbean Sea. We measured illuminance to a level of 0.1 lux, organic matter (weight loss on ignition), temperature, and relative humidity. The last two were measured at hourly intervals for nearly one year. Approximately one-third of the cave has illuminance values greater than 0.01 lux, and most of the rest of the cave has light as well. Temperature and relative humidity were relatively constant, but they showed a daily cycle at all stations, albeit with different strengths. Organic matter averaged 8%, intermediate …

A Study Of Marine Terrace Formation Along The California Central Coast, Mary C. Devlin

Natural Resources Management and Environmental Sciences

Marine terrace formation is in many instances attributed to wave action, and shore platforms are often called “wave-cut”. However, alternative models for marine terrace formation suggest that other types of physical and chemical weathering have a more central role in the formation of marine terraces than is widely acknowledged. Roering and Retallack (2012) concluded that the roles of subaerial physical and chemical weathering are significant, and played a major role in the formation of the terraces. In this study, weathering of beach cliffs and shore platforms associated with marine terraces at eight sites in two different locations along the central …

Bedrock Geology Of Dfdp-2b, Central Alpine Fault, New Zealand, Virginia Gail Toy, Angela Halfpenny

All Faculty Scholarship for the College of the Sciences

During the second phase of the Alpine Fault, Deep Fault Drilling Project (DFDP) in the Whataroa River, South Westland, New Zealand, bedrock was encountered in the DFDP-2B borehole from 238.5–893.2 m Measured Depth (MD). Continuous sampling and meso- to microscale characterisation of whole rock cuttings established that, in sequence, the borehole sampled amphibolite facies, Torlesse Composite Terrane-derived schists, protomylonites and mylonites, terminating 200–400 m above an Alpine Fault Principal Slip Zone (PSZ) with a maximum dip of 62°. The most diagnostic structural features of increasing PSZ proximity were the occurrence of shear bands and reduction in mean quartz grain sizes. …

Geology Of The Middle Member Of The Bakken Formation In Divide County, North Dakota, Mandy Brewer

Graduate Theses & Non-Theses

The Upper Devonian-Lower Mississippian Bakken Formation of Williston Basin is a large unconventional oil and gas play consisting of a lower shale member, a middle member, and an upper shale member. The middle member is a production target because it contains porosity and petroleum expelled from the shale members around it. Variable production and sweet spots of the Bakken in the study area of Divide County, ND and 15 miles around Divide County in the USA prompted a closer look at middle member Bakken sediments. For this study, 606 wells were correlated and thin sections from two wells located 10.17 …

Copper Isotope Constraints On The Genesis Of The Keweenaw Peninsula Native Copper District, Michigan, Usa, T. J. Bornhorst, Ryan Mathur

A. E. Seaman Mineral Museum Publications

The Keweenaw Peninsula native copper district of Michigan, USA is the largest concentration of native copper in the world. The copper isotopic composition of native copper was measured from stratabound and vein deposits, hosted by multiple rift-filling basalt-dominated stratigraphic horizons over 110 km of strike length. The δ⁶⁵Cu of the native copper has an overall mean of +0.28‰ and a range of −0.32‰ to +0.80‰ (excluding one anomalous value). The data appear to be normally distributed and unimodal with no substantial differences between the native copper isotopic composition from the wide spread of deposits studied here. This suggests …