Earth Sciences Commons^™

Effects Of Gradation And Moisture Content On Resistivity Of Mechanically Stabilized Earth Wall Backfill Materials, Jose Luis Arciniega

Open Access Theses & Dissertations

The service life of mechanically stabilized earth (MSE) walls depends on the corrosion rate of the metallic reinforcement used in their construction. The resistivity of the backfill aggregates needs to be measured accurately in order to estimate realistically the corrosion rate of the reinforcement. Resistivity testing is usually performed using the traditional soil box on the portion of the aggregates that passes a No. 10 or No. 8 sieve to either select or reject the backfill. For a more reasonable characterization of the corrosivity of coarse backfills, it is desirable to use their actual gradations. To that end, several resistivity …

Effects Of Increasing Deciduous Shrub Litter On Ecosystem Functioning In Alpine Tundra, Alejandro Emmanuel Benhumea

Open Access Theses & Dissertations

Rising temperatures due to global warming have resulted in rapid environmental changes in northern environments, resulting in an increase in deciduous shrub growth which has the potential to alter soil ecosystem properties and processes. In order to address some potential mechanisms by which shrubs alter ecosystem properties and processes, we designed an experiment which separated the effects of physical shrub presence and the effects of litter quantity in a fully factorial experiment on a north facing alpine plateau in the southwest Yukon, Canada. Specifically, we asked the following questions: What are effects of shrub litter, independent of shrub presence, on …

Biologically Available Phosphorus In Biocrust-Dominated Soils Of The Chihuahuan Desert, Grace Margaret Crain

Open Access Theses & Dissertations

In desert soils, phosphorus (P) is an important limiting nutrient and its cycling characteristics are less understood compared to nitrogen and carbon. Phosphorus cycling is controlled by both geochemical and biological factors. Traditionally, P availability has been characterized via sequential extraction analyses such as Hedley fractionation, but newly developed extraction methods allow for the examination of more biologically relevant P fractions, providing insight on mechanisms of P acquisition by plants and microbes. We examined these P cycling features in the context of biological soil crusts (biocrusts), which have been found to be important drivers of nutrient cycling and have the …

Evaluating Fold And Thrust Systems Within An Inverted Basin: Indio Mounntains, West Texas, Myra Guerrero

Open Access Theses & Dissertations

Fold and thrust belts often are complicated by out of sequence thrust faulting and inverted basins display these structures particularly often due to reactivation of original normal faults as well as complex topographic evolution. The Indio Mountains lie along the northern margin of the Chihuahua trough which formed as a mid-Cretaceous extensional basin and was subsequently shortened during the Laramide orogeny, making the Indio Mountains an exceptional site for studies of structures produced by large scale basin inversion. This study focuses on the subsurface structures in a complexly imbricated thrust window developed along the paleo rift basin margin.

This study …

Gravitational Analysis And Fault Identification Within An Active Rift Basin: The Mesilla Valley Bolson In Western Texas - Southern New Mexico, Jose Pablo Cervantes

Open Access Theses & Dissertations

The metropolitan region of El Paso Texas and Ciudad Juárez, Chihuahua, located within the northern Chihuahua Desert, contains approximately two million inhabitants. The two main aquifers that supply groundwater to this region are the Mesilla and Hueco Bolsons. Both bolsons have been tapped for decades without sustainable recharge. This study's purpose is to use geophysical methods coupled with published geochemical analyses to determine the structural and stratigraphic controls on the quality and quantity of groundwater in the southern Mesilla Bolson.

The Mesilla Bolson is one of many fault-controlled basins within the Rio Grande Rift - southern Basin and Range. Faults …

Trace Metal And Metalloid Behavior In The Submicron Scale Components Of Coal Fly Ashes: Insights From Combined Microscopic And Microbiological Studies, Matthew Costa

Open Access Theses & Dissertations

For over a century, coal has been used worldwide to meet ever-growing energy demands. Coal combustion accounts for over 30% of electricity generation in the United States. In the U.S., coal combustion produces annually over 100 million tons of coal combustion products (CCPs) of which only 30% are used in beneficial and economic ways. One of the primary CCPs from coal-burning power plants is fly ash, typically fine-sized and enriched in many trace elements (e.g., arsenic, chromium, lead, and vanadium). When disposed in the environment, fly ash may release significant concentrations of trace elements into surrounding ecosystems and induce toxicity …

Attributes Of The Fisher Valley Megaflap And Comparison To The Gypsum Valley Megaflap, Paradox Basin, Utah And Colorado: Implications For Controls On Megaflap Formation, Kate Grisi

Open Access Theses & Dissertations

Megaflaps are panels of steeply dipping to overturned strata that extend kilometers up the side of a salt diapir or equivalent weld. They often form important components of salt-diapir related hydrocarbon systems, though little is known about their geologic characteristics or how they form. In this study, I collected structural, stratigraphic, and sedimentologic data of the Fisher Valley megaflap and compared these attributes to the previous studied Gypsum Valley megaflap to test the differential sediment loading model proposed for initiation of megaflap formation. This model predicts that the sediment source proximal megaflap of Fisher Valley should have started rotation earlier, …

Assessing The Hydrologic Impacts Of Extreme Rainfall And Land Use Change On A Semiarid Watershed, Tahneen Jahan Neelam

Open Access Theses & Dissertations

Abstract: Intense precipitation events increase the risk of flash floods in the New Mexico-Texas-Mexico border region. Compounding effects of changing land use and precipitation pattern can influence rainfall-runoff processes that govern flash flooding. Paradoxically, this southwestern semiarid watershed has substantial water conflict that may get worse by 2025 due to changing climate and increasingly competitive demands for over-appropriated water resources. Using Soil and Water Assessment Tool (SWAT), we investigate the impact of changes in precipitation intensity and land use on runoff and arroyo flows in the dry, mountainous terrains. The baseline watershed simulation model shows that for a statistically insignificant …

Facies Changes Associated With Formation Of An Extensive Salt Shoulder By The Coastal And Eolian Carmel And Entrada Formations, Gypsum Valley, Colorado, Ryan Burtron Ronson

Open Access Theses & Dissertations

A salt shoulder forms a zone at the margin of a salt diapir where that margin steps relatively abruptly inward. These shoulders form when the salt rise rate near the diapir margin substantially decreases or stops relative to the salt rise rate at the inboard central part of the diaper. Based on current models of interactions between these salt shoulders and overlying sediment, it was anticipated that the thickness changes of the Entrada and Carmel formations would be only gradual and that any notable thinning would take place proximal to the neck portion of the diapir that would still have …

Geophysical Studies Of Southwestern Part Of The North American Craton, Luis Martin Sandoval Magallanes

Open Access Theses & Dissertations

The present study, based on combined geophysical, geochronological and isotopic data identifies a cratonic block which we call the Western Chihuahua-Mesa Central megablock (WCMB) in northern Mexico. New Bouguer and isostatic gravity anomaly maps revealed a conspicuously distinct, spatially-extensive gravity minima over a region extending from north western Chihuahua to as far south as the Mesa Central (MC). This region can be differentiated from the surrounding mobile belts with significantly higher gravity anomaly values. Gravity modeling combined with sparse seismically determined crustal thickness estimates indicate that the proposed WCMB region has crustal thicknesses ranging from 38 to 42 km. The …

Geostatistical And Geospatial Distribution Of Multiple Metallic Elements In Agricultural Regions Of The Mid-Continental Usa, Najwah Alssaeidi Ahmed Almesleh

Open Access Theses & Dissertations

Regional geochemical mapping constitute the chemistry of the surface of the earth in a large scale and relatively low sample density. It is widely accepted scientific activity and man uses some cases to identify contamination. In the present study, data present in national geochemical survey database was used to investigate the chemical loading loading of the agricultural soil. In the mid-continent region of the United States. Several traditional parameters were used mainly the enrichment factor (EF), and geoaccumulation index (I geo). Total chemical influence (TCI) maps were used to guide sampling. In addition, regional trace element chemistry of bedrock was …

A Machine Learning Approach To Rendering 3d Stratigraphic Models Of The Hueco Bolson, Western Texas And Northern Mexico, Joel Gerardo Castro

Open Access Theses & Dissertations

Data visualization is an effective way to analyze large amounts of spatial information to identify correlations, trends, outliers, and patterns. In this Thesis I test the application of supervised machine learning algorithms to render a series of 3D visualizations designed to highlight general traits of the Hueco Bolson, a geologic basin located east of the Franklin Mountains in far west Texas and northern Mexico. A geologic basin is one of the most common inland places where sediments are collected. The geology of basins is of much interest to geophysicists, hydrologists, paleontologists, and oil prospectors. Here the task of 3D geologic …

Investigating The 2016 Jackson, Wyoming Earthquake Sequence Using Waveform Cross-Correlation And Seismic Array Methods, Emily Jo Graves

Open Access Theses & Dissertations

During a visual inspection of PDAR data extracted for the catalog events, I observed additional, unreported events, which is to be expected during an energetic swarm or seismic sequence. The casual observation of missed events strongly implied that more such missed events could be found in the data, which could improve the completeness of the earthquake catalog for the Jackson, Wyoming area. Catalog completeness improves our assessment of a region's tectonic behavior and earthquake exposure. To search for recurring swarm or earthquake sequence behavior, I applied waveform correlation methods to scan nearly two decades of continuous PDAR waveforms, comparing to …

Comparison Of Mesoscopic Fracture Analysis Techniques: A Case Study Near Onion Creek Diapir, Paradox Basin, Utah, Muhammed Tarik Iraz

Open Access Theses & Dissertations

Faults and fractures are abundant along the diapir contact in the Onion Creek Diapir in eastern Utah and relate to the mechanisms of diapir formation. Western Onion Creek exhumes two spectacular exposures of the diapir contact and adjacent wall rocks providing two nearly orthogonal transects oriented ~E-W and S-N. In this study, I used field measurements from natural outcrops and a 3D model developed using Structure-from-Motion/Multiview Stereo photogrammetry to evaluate fracture reservoir development along diapir margins. The 3D-Model was developed using Agisoft Photoscan from ~3200 ground-based images and was georeferenced using 76 ground control points located with a GPS unit …

Onshore-Offshore Velocity Models North Of The Mendocino Triple Junction In Northern California, Alan Jacquez

Open Access Theses & Dissertations

The Mendocino Triple Junction (MTJ) marks the boundary where the Gorda plate, North American Plate, and Pacific Plate meet, separating the Cascadia subduction zone to the North from transform tectonics of the San Andreas plate boundary. This actively deforming region experiences high seismic activity and young geological features. Here we examine offshore and onshore seismic wide-angle reflection and refraction data north of the MTJ crossing the Cascadia subduction zone from offshore northern California to the Western edge of the Sierra Nevada. We image subsurface structures in this region by creating P-wave velocity models using datasets collected in 1993 to 1994 …

Magnetotelluric Analysis Of Central Kenya Kenyan Rift Volcanoes For Geothermal Development, Anna Wairimu Mwangi

Open Access Theses & Dissertations

Abstract

High temperature geothermal resources are vast along rift margins because of emplacement of magma in shallow crust. This is the case along the Kenyan Rift valley also known as the Gregory Rift. It is the Eastern arm of the East African rift and a chain of volcanoes along the rift graben characterizes it. We use (MT) magnetotelluric method to image beneath the peralkaline province of the Kenya Rift i.e. Olkaria, Eburru, Badlands, and Longonot volcanoes. The resistivity structure shows active geothermal activity happening at the upper 3km from the subsurface as evidenced by low resistivity cap rock comprised of …

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 …

Geometry, Timing, And Kinematics Of Neogene Extensional And Transtensional Structures Of Southern Death Valley: Implications For Regional Reconstructions And A Corrective Method For Rigid Body Rotations, Zachariah Fleming

Open Access Theses & Dissertations

Chapter 1:Advancements in computing capabilities over the last decade have allowed for the routine creation of Structure from Motion-Multiview Stereo (SfM-MVS) terrain models that can serve as base for high resolution geologic mapping. Outcrops models developed from these systems are high-resolution, photo-realistic 3D base providing unprecedented capability for geometric analysis. Yet, before this technology becomes a mainstay of field geology, the potential errors associated with it must be well understood. Here, we compare orientation measurements from multi-point analyses on the SfM-MVS point clouds to those taken in the field with the objective of resolving the geometry of complex folds within …

The Sedimentary Record Of Eocene Deformation In The Interior Of The Southern Canadian Cordillera, Erica May Rubino

Theses and Dissertations

Eocene sedimentary strata exposed in the interior of the southern Canadian Cordillera (SCC) in British Columbia (BC) and northernmost Washington (WA) record a poorly understood history of extension-related deformation in the hinterland of the orogen. Today these strata are exposed in isolated, distinct outcrop belts, although the nature of the original basin(s) is unknown. We examined 650 m of Eocene strata, analyzed 2,995 detrital zircons for uranium-lead (U-Pb) ages, and measured 67 detrital zircons for Hf isotope systematics in an effort to better understand the physiography of the SCC during this time period. Eocene strata consist of clast- and matrix-supported …

Organic Acids And Amino Acids In Serpentinization Related Fluids From The Atlantis Massif, Nicholas Camper

Theses and Dissertations

Serpentinization is a low temperature, low pressure process that occurs when water reacts with ultramafic rocks. Fluids that have interacted with serpentinites have elevated concentrations of hydrogen and reduced carbon species that can fuel chemolithoautotrophy. International Ocean Discovery Program Expedition 357 drilled a series of boreholes into the Atlantis Massif with the goal of investigating how serpentinization impacts carbon cycling and sustains life in the subseafloor. Bottom water samples (CTD), fluids flushed from the boreholes during drilling (Rock Drill), and fluids that were trapped in the liners of the cores (Liner fluids) were collected. The changes and distributions of organic …

Classifying The Woody Vegetation Community Of Wade Ponds In Colleton County, South Carolina, Wade Biltoft

Theses and Dissertations

Wetland habitats are some of the most biodiverse ecosystems in the world, varying in both physical and biological characteristics. Geographically isolated wetlands are particularly important to the landscape due to their role in the hydrological cycle and as local centers for biodiversity. In parts of the coastal plain of South Carolina, there are geographically isolated wetlands found in concentrated groups with distinctive size, shape, and distribution. Despite their unique appearance and distribution, these wetlands have been scarcely researched or investigated. This project seeks to explore the plant communities that are contained within these ponds in order to understand their composition …

Encrusting Sclerobiont Paleoecology And Bioerosion Of Oysters In The Type Campanian (Upper Cretaceous) Of Southwestern France, Macy A. Conrad

Senior Independent Study Theses

The Campanian Stage of the Upper Cretaceous was established by Henri Coquand in 1857 based on a sequence of richly fossiliferous shallow water carbonates in the Charente and Charente-Maritime departments of southwestern France. One of the most common macrofossils is the gryphaeid oyster Pycnodonte vesicularis (Lamarck, 1806), which often forms extensive shell beds. This bivalve lived primarily on soft marly substrates, forming hard substrate islands. They frequently supported sclerobiont communities comprising encrusters (diverse cheilostome and cyclostome bryozoans, foraminiferans, oysters, bivalves, sabellid and serpulid polychaetes, calcareous sponges), borers (the sponge borings Entobia, the worm borings Maeandropolydora and Caulostrepsis, the barnacle borings …

Using N-Alkane As A Proxy To Reconstruct Paleoenvironment In Thale Noi, Phatthalung Province, Assuma Sainakum

Chulalongkorn University Theses and Dissertations (Chula ETD)

Normal alkane (n-alkane) is the widely used hydrocarbon proxy for the paleoenvironmental study because of their specific characteristic and resistance to microbial degradation. The n-alkanes from the sediment cores TLN-CP5 and TLN-CP7 from Thale Noi, Phatthalung Province, were analyzed and subsequently compared with those derived from the recent plant samples. The plant samples were taken from mangrove forests, i.e. true mangrove, back mangrove, and mangrove associate, based on the previous study on pollen analysis. The n-alkane distributions, the average chain length (ACL), the carbon preference index (CPI) and the proportion of aquatic components (Paq) were further analyzed in order to …

Lithological Classification By Deep Learning Algorithm, Worapop Thongsame

Chulalongkorn University Theses and Dissertations (Chula ETD)

Six machine learning algorithms are used to classify subsurface rocks based on fifteen well logging features from four geothermal wells in the Snake River Plain, Idaho, USA. Two experimental designs, single- and multiple-well tests, are developed to determine the most optimal model and hyperparameters. The single-well test randomly assigns the data in each well into 70% for training set, 10% for validation set, and 20% for test set. The multiple-well test combines data from three wells and splits the data in the fourth well into 70% for training set, 10% for validation set, and 20% for test set. Results show …

Seismic Characteristics Of Paleo-Pockmarks At Great South Basin, New Zealand, Arunee Karaket

Chulalongkorn University Theses and Dissertations (Chula ETD)

Paleo-pockmarks and present-day pockmarks are founded in several varieties both onshore and offshore worldwide. These features can be used as an indicator of fluid flow process which expulses through an unconsolidated sediment within the basin. The Great South Basin, New Zealand is one of the basins that paleo-pockmarks are observed covering the southeast offshore of South Island at around 1.5 s (TWT) depth beneath the surface. This study aims to identify seismic characteristics of paleo-pockmarks in the Great South Basin and predict the possible fluid origins and their mechanism. The numerous paleo-pockmarks are identified and imaged by using 3D seismic …

The Influence Of Geological Structure On Stratigraphic Development During Multiphase Rifting In The Songkhla Basin, Gulf Of Thailand, Jidapa Phoosongsee

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Cenozoic N-S trending Songkhla rift basin, located in the southwest Gulf of Thailand, was developed as a predominantly orthogonal extended half graben structure. The half graben is controlled by a boundary fault zone on the western side of the basin, which forms a series of N-S to NNE-SSW, east-dipping normal faults. The rift spans two phases of rifting; the Eocene-Oligocene and the Oligocene-Miocene phases, the late syn-rift to post-rift transition occurred from the late Early Miocene to Middle Miocene. The main clastic hydrocarbon reservoirs in the basin are located in the Early Miocene to Middle Miocene section. These reservoirs …

Influences Of Geologic Conditions And Anthropogenic Activities On Changes Of Geomorphology And Sediment Load Characteristics Of The Ping And Chao Phraya Rivers, Nikhom Chaiwongsaen

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Chao Phraya River flows into the largest river basin of Thailand. The Ping River is one of its the major upstream branches flowing down slope southwardly, joining the Chao Phraya River in the central plain and ends at the Gulf of Thailand. The sand-choked is extensively observed and the flood overflow occurs frequently and rapidly at the Lower Ping River. In contrary, the Chao Phraya River, the erosion of river bank and shoreline around the river mouth has been spatially increasing in place. The Landsat imageries taken in 1987, 1997, 2007 and 2017 were used to analyze geomorphological changes …

Aftershock Analysis In The Mainland Southeast Asia, Premwadee Traitangwong

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, the characteristics of the aftershock in the mainland Southeast Asia (MSEA) were investigated using the several seismological techniques, i.e., i) the Gutenberg-Richter relationship (G-R relationship) ii) the modified Omori's law iii) the Bath's law and iv) the fractal dimension. After declustering, 1,697 clusters during 1985-2017, which represent the aftershocks occurring after mainshock were investigated in 13 seismic source zones recognized in the MSEA. According to the Bath's law, the maximum magnitude of the aftershock depends on the magnitude of the mainshock, with the difference value between 0.4-2.5. In the intraplate zone, it is less than in the …

Mineral Inclusions In Ruby And Sapphire From Bo Welu And Bo Rai Deposits, Eastern Thailand, Supparat Promwongnan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Corundum deposits located in several places around the world which appear to have different genesis models. The origins of corundum can be distinguished by mineral inclusions. In this study, most of the rough gem corundum from Bo Rai deposit, Trat Province, and Bo Welu deposit, Chanthaburi Province, in Eastern Thailand show etched or dissolved surfaces that were resulted from dissolution by hot basaltic magma during transportation to the surface. Moreover, these gem corundums also show absorption spectral characteristics related to trace elements which typical for corundum from this area. Corundums from Bo Rai deposit in Trat Province, and from Bo …

Trace Element And Isotopic Fingerprinting Of Olivine Phenocrysts As Recorders Of Magmatic Processes In The Golden Trout Volcanic Field, Kern Plateau, Ca, Mark E. Szymanski

Cal Poly Humboldt theses and projects

Quaternary mafic volcanism in the western Basin and Range and in the southeastern Sierra Nevada is largely controlled by extensional stresses that promote magma generation through decompression melting of the lithospheric and asthenospheric mantle. Where volcanism occurs in the Sierra Nevada, like at the Golden Trout Volcanic Field GTVF), the eruption rate, number of vents, and eruption volume is an order of magnitude less than at neighboring Basin and Range volcanic fields such as the Big Pine Volcanic Field (BPVF). To determine the factors that cause these differences in adjacent and contemporaneous volcanic fields, I sampled rocks from both fields …