Digital Commons Network^™

Hvsr-Based Resonance Analysis And Fault Zone Characterization In The El Paso Region, Alexandro Dominguez

Open Access Theses & Dissertations

Horizontal to Vertical Spectral Ratio (HVSR) analysis offers an efficient method for characterizing near-surface structure, resolving sediment thickness, and identifying fault-controlled basin geometry in regions with strong impedance contrasts. This study applies HVSR techniques to continuous ambient-noise recordings collected across the El Paso region, a tectonically active segment of the southern Rio Grande Rift where accurate subsurface mapping is essential for seismic hazard assessment. Ambient-noise windows were processed, spectrally smoothed, and stacked to obtain stable HVSR curves, from which fundamental resonance frequencies and corresponding sediment-thickness estimates were derived. Spatial patterns in these resonance frequencies reveal pronounced basin asymmetry, abrupt lateral …

Enhancing Basic Geology Skills With Artificial Intelligence: An Exploration Of Automated Reasoning In Field Geology, Perry Ivan Quinto Houser

Open Access Theses & Dissertations

This thesis explores the use of Artificial Intelligence, specifically semantics, ontologies, and reasoner techniques, to improve field geology mapping. The thesis focuses on two use cases: 1) identifying a geologic formation based on observed characteristics; and 2) predicting the geologic formation that might be expected next based upon known stratigraphic sequence. The results show that the ontology was able to correctly identify the geologic formation for the majority of rock descriptions, with higher search results for descriptions that provided more detail. Similarly, the units expected next were correctly given and if incorrect, would provide a flag to the field geologist …

Tectonomagmatic Evolution Of Northwestern Mexico, And Applications Of Machine Learning In Economic Geology, Jose Antonio Garcia

Open Access Theses & Dissertations

The work presented here was conducted in two study areas: La Preciosa mining project (Chapters 1 and 2) and Ray Mine (Chapter 3). Chapter 1 of this dissertation contributes to the tectonomagmatic evolution of northwestern Mexico by focusing on the temporal changes in magma source(s) regions, magma generation processes, and tectonic implications. In this chapter, I provide thin section analyses, whole rock geochemistry, in-situ zircon U-Pb ages and Hf isotope compositions of subsurface lithologies from La Preciosa mining project; located in the northwestern corner of Mesa Central, Durango, Mexico. The newly acquired data identified five magmatic events. The first consists …

Measurement Of Radon Gas At Kilbourne Hole, Michel Eduardo Luna Lucero

Open Access Theses & Dissertations

Several radon studies have reported a possible correlation of the gas emanation with faults and seismic activity in the area, but few studies have been conducted in seismically inactive areas. Features such as the Kilbourne Hole in New Mexico, a maar volcano formed by an interaction between magma and water, can reveal important information about connection between radon concentration levels and structural geology.

The purpose of this thesis is to determine the radon concentration levels in and around the crater of the Kilbourne Hole. The results are compared with geological, gravity and magnetic surveys to have a better understanding of …

Geophysical Studies Of The Three Sisters Andesite, West El Paso, Texas, Alexander D'Marco Garcia

Open Access Theses & Dissertations

The Three Sisters andesite intrusion is part of series of three small igneous bodies that crop out in western El Paso to the north of the more extensive intrusions found on the University of Texas at El Paso campus and at Mount Cristo Rey. These Oligocene age intrusions are believed to form part of a deeper, more extensive igneous body that may lie beneath much of western El Paso and the southern Mesilla Valley. I used several geophysical techniques to determine the size and shape of the Three Sisters intrusion to better understand its connection to other andesite outcrops and …

Petrophysical, Geostatistical And Geo-Spatial Analysis Of Round Top Mountain Rhyolite (Hudspeth County, West Texas, Usa), Lorraine Marie Negron

Open Access Theses & Dissertations

This project consists of three separate projects that all investigate Round Top Mountain, a rhyolite laccolith located in Sierra Blanca, west Texas in Hudspeth County (U.S.A). The three projects will explore and analyze the petrophysical, geostatistical and geo-spatial aspects of this unique deposit.

Project 1:

This petrophysical study examines the porosity and micro-permeability of the Round Top rhyolite at a scale, roughly 5 to 10 mm or pebble sized, similar to anticipated heap leach crush sizes. Large voids and fluid paths, such as faults and joints in the massive rock (meter to km scale, boulder to outcrop size), are not …

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 …

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 …

Constraining Times Of Extension In The Southern Rio Grande Rift And Basin And Range Using Apatite And Zircon (U-Th)/He Thermochronology, Julian Biddle

Open Access Theses & Dissertations

The Rio Grande rift and the Basin and Range are adjacent extensional domains that have evolved contemporaneously in western North America. Although the rift is often considered to be the easternmost boundary of Basin and Range extension, there is geologic and geophysical evidence that suggests the two are discrete provinces. Existing low-temperature thermochronologic data indicate that a period of synchronous extension occurred across the entire length of the rift from ~25-10 Ma. However, these studies were more focused on the northern and central sections of the rift, and thermochronologic data remains sparse in southern New Mexico. We collected rock samples …

Evaluating Methods Of Field-Based 3d Visualization And Their Application To Mapping Metamorphic Terranes: An Example From The Panamint Mountains, California, Jade Ashley Brush

Open Access Theses & Dissertations

Field geology has traditionally relied on 2D, paper-based workflows, but digital mapping techniques are rapidly replacing these outdated methods because they allow for more efficient and accurate mapping. This research applies digital mapping techniques and two terrestrially-based 3D visualization technologies, photogrammetry and Light Detection and Ranging (LiDAR), to the study of metamorphic terranes in the Panamint Mountains, California. This study reports on the spatial accuracy of TINs (triangulated irregular networks) generated from both photogrammetry and ground-based LiDAR using a terrestrial laser scanner (TLS) and discusses how spatial accuracy can be increased. Two levels of comparison were used to test spatial …

Reinterpretation Of The Mesozoic Thrust Complex Of The Southern Spring Mountains, Nevada, Warren Harding Allen

Open Access Theses & Dissertations

The east verging Keystone thrust fault in the southern Spring Mountains west of Goodsprings, Nevada, is mapped with a sharp bend in its trace near Keystone Wash. This bend was previously explained in the context of out-of-sequence thrusting and a salient-recess relationship along the thrust system; a simple redirection of the Keystone thrust to a north verging thrust. Recent geochronological studies indicate that the east verging Keystone thrust to the north of Keystone Wash formed between 83-103Ma. Approximately 5 kilometers to the east a north verging branch of the fault system overlies rocks as young as 99Ma. At the location …

Receiver Function Analysis To Study Crustal Structure Of The Northern Nepal And Tibetan Plateau, Mohan Pant

Open Access Theses & Dissertations

The teleseismic P-waveform receiver function analysis is a commonly used technique in earthquake seismology to study the crustal structure beneath a broadband seismic station. To understand the structure of the Northern Nepal and Tibetan plateau different studies have used the receiver function method to estimate the Moho depth and Vp/Vs ratio. The value suggested was ~ 30 km in the south and the ~ 75 km in the north. Other studies have used teleseismic body wave data to perform the travel time residuals to model the lithosphere structure. In our study, we analyzed data from 261 seismic stations to establish …

A Geophysical Study Of The Castle Mountain Fault System And Matanuska-Susitna Valley Near Anchorage, Alaska, Shane Michael Schinagel

Open Access Theses & Dissertations

The Castle Mountain Fault (CMF) is the closest (~50 km) active fault to Anchorage, Alaska. Located within the Matanuska and Susitna (Matsu) Valleys, the CMF shows repeated, unmistakable evidence for Holocene motion. Recent geologic studies estimate that this fault is capable of producing earthquakes of magnitude 7.0 - 7.1. The Anchorage metropolitan area (which includes the Matsu Valley) contains most of Alaska's population as well as vital shipping and transportation facilities that serve much of inland Alaska. Expected magnitude >7 earthquakes pose seismic hazards to the expanding Anchorage area.

While several mapping and trenching studies have been conducted along the …

Application Of Various Remote Sensing And Aerial Photography Data Sets To Resolve Surface Structure In Areas Of Poor Exposure: Examples From Kamchatka Peninsula, Russia And Katalla Area, Alaska Usa, Sarah Natalie Heinlein

Open Access Theses & Dissertations

For many years now remote sensing data sets and application techniques of these various data have been routinely used in geological studies. Some of these studies are as basic as using Google Earth applications for general reconnaissance to more sophisticated methods for energy exploration or development of active tectonic models for a region. This dissertation presents data from two study areas within the northern pacific region utilizing a number of remote sensing and aerial photography data: 1) Kamchatka Peninsula, Russia, and 2) Katalla area of southern Alaska, USA. The Kamchatka Peninsula, Russia study evaluates surface geomorphology which includes the morphology …

Constraints On The Structure Of The Border Ranges Fault System, South-Central Alaska From Integrated 3d Inversion Of Gravity/Magnetic Data, Niti Mankhemthong

Open Access Theses & Dissertations

I use updated gravity data, available aeromagnetic data, and other geophysical information as constraints to develop 2D and 3D structural models of density and magnetic susceptibility to better locate and determine the shape of the Border Ranges fault system (BRFS), the Border Range ultramafic and mafic assemblages and other forearc-arc boundary structures in south-central Alaska, that have previously been studied in only limited detail. There are three geophysical research projects that form the chapters of the dissertation. First, I estimated near-surface density variations in the central Kenai Peninsula based on the adaptation of the Nettleton (1939)-Parasnis (1952) method using Tarantola …

Three-Dimensional Deformation And Stress Models Of The Death Valley And San Andreas Fault Zones, Cecilia Del Pardo

Open Access Theses & Dissertations

Crustal deformation studies of tectonic motions have been the topic of many scientific investigations, as they can provide critical information about how tectonic structures shape and deform the Earth. While crustal deformation studies using observational data alone can provide a great deal of information about how the Earth is presently deforming, it is standard practice to implement mathematical and physics-based models to investigate the underlying causes of deformation in the crust. These models, constrained by geological, geodetic and seismic data, have successfully contributed key constraints of ongoing deformation processes and have provided predictions of past and future tectonic behavior of …

On Constrained Optimization Schemes For Joint Inversion Of Geophysical Datasets, Uram Anibal Sosa Aguirre

Open Access Theses & Dissertations

In the area of geological sciences, there exist several experimental techniques used to advance in the understanding of the Earth. We implement a joint inversion least-squares (LSQ) algorithm to characterize one dimensional Earth's structure by using seismic shear wave velocities as a model parameter. We use two geophysical datasets sensitive to shear velocities, namely Receiver Function and Surface Wave dispersion velocity observations, with a choice of an optimization method: Truncated Singular Value Decomposition (TSVD) or Primal-Dual Interior-Point (PDIP). The TSVD and the PDIP methods solve a regularized unconstrained and a constrained minimization problem, respectively. Both techniques include bounds into the …

Results Of New Petrologic And Remote Sensing Studies In The Big Bend Region, Stevan Christian Benker

Open Access Theses & Dissertations

The initial section of this manuscript involves the South Rim Formation, a series of 32.2-32 Ma comenditic quartz trachytic-rhyolitic volcanics and associated intrusives, erupted and was emplaced in Big Bend National Park, Texas. Magmatic parameters have only been interpreted for one of the two diverse petrogenetic suites comprising this formation. Here, new mineralogic data for the South Rim Formation rocks are presented. Magmatic parameters interpreted from these data assist in deciphering lithospheric characteristics during the mid-Tertiary.

Results indicate low temperatures (< 750 °C), reduced conditions (generally below the FMQ buffer), and low pressures (≤ 100 MPa) associated with South Rim Formation magmatism with slight conditional differences between the two suites. Newly discovered fayalite microphenocrysts allowed determination of oxygen fugacity values (between -0.14 and -0.25 ΔFMQ over temperature ranges of 680-700 °C), via mineral equilibria based QUILF95 calculations, for Emory Peak Suite.

Petrologic information is correlated with structural evidence from Trans-Pecos Texas and adjacent regions to evaluate debated timing of tectonic …

Resistivity And Conductivity Studies Of The Rattlesnake Springs, New Mexico Watershed, Claudia Santiago

Open Access Theses & Dissertations

Rattlesnake Springs are a high-discharge artesian springs situated in the upper Black River Valley in southwestern Eddy Country, New Mexico. The aquifer that supplies the Rat- tlesnake Springs has been the main water source for domestic use by visitors of Carlsbad Caverns National Park and residents of neighboring ranches since the 1930s. Several ge- ological studies relying on surface geology and limited water wells had previously been conducted in the area to examine the trend of ground water flow. In this study I used con- ductivity and resistivity geophysical techniques to identify possible locations of fractures in the subsurface of …

Temporal And Geochemical Insights Related To Volcanic And Plutonic Activity Within Big Bend National Park, Texas, Daniel Paul Miggins

Open Access Theses & Dissertations

Big Bend National Park located in the southeastern part of the Trans-Pecos Magmatic Province in west Texas contains a diverse suite of volcanic and intrusive rocks. Ongoing geologic mapping, geochronology, and geochemical studies have focused on the timing and geological relationships associated with these volcanic and intrusive rocks. Igneous activity within Big Bend National Park occurred from 46.5 to 22.0 Ma. Precise 40Ar/39Ar and U-Pb zircon geochronology has resolved the timing of this activity into five discrete episodes: 1) eruption and emplacement of both intrusive and volcanic mafic rocks at 46.5 Ma followed by ~42.0 Ma mafic volcanic pulse; 2) …

Integrated Geophysical Data Processing And Interpretation Of Crustal Structure In Ethiopia With Emphasis On The Ogaden Basin And Adjacent Areas, Ketsela Tadesse

Open Access Theses & Dissertations

The combined effects of magmatism and stretching due to asthenosphere upwelling modifies the crustal structure of the Earth as seen in the Ethiopian rift and adjacent areas. The Ethiopian rift provides unique opportunities to understand the nature of rifted crust and the intensity of its modification by magmatic processes. I used geological and geophysical data to conduct an integrated study in and around the Ethiopian rift including the northern Kenyan rift and the northern part of the Kenyan dome. New gravity, controlled source seismic, and teleseismic data from the EAGLE (Ethiopia-Afar Geoscientific Lithospheric Experiment) were used as additional constraints in …

Lithospheric Structure Of The Basin And Range Province-Southwestern Colorado Plateau. Southeastern California, Southern Nevada, And Western Arizona, Nigel Oakley Hicks

Open Access Theses & Dissertations

The Basin and Range Province of the western United States is an unusually wide continental rift zone and its structure and evolution have been the topic of much debate. Active source seismic surveys within the Basin and Range Province have delineated a relatively uniform crustal thickness (-30 km) despite varying magnitudes of crustal extension (<10-300 km). Large scale Cenozoic crustal extension has exhumed midcrustal rocks (from 10-20 km depth) along low angle detachment faults to create metamorphic core complexes (exposed lower plate rocks). In contrast to the extreme amounts of extension and internal deformation of the Basin and Range, the Colorado Plateau has remained a relatively rigid block, with a crustal thickness of 40-50 km, apparently resistant to the deformation processes that have shaped the Basin and Range observed today. In general, geophysical surveys reveal a significant contrast in crustal structure between the Basin and Range and it's transition into the Colorado Plateau.

The debate about the origin of the Basin and Range has underscored the need for additional geophysical constraints. Thus in this study, a regional analysis of lithospheric structure in the region of southeastern California, southern Nevada, and western Arizona that includes the Basin and Rangesouthwestern …