Physical Sciences and Mathematics Commons^™

Investigating Changes In Surface Water Chemistry Across The Llano Uplift And The Balcones Fault Zone In Central Texas Using Strontium And Uranium Isotopes, Hao Tuan Pham

Open Access Theses & Dissertations

The landscape of central Texas is shaped by over one billion years of Earth's history. An array of lithology lies within central Texas along with two large geological structures. The Llano Uplift, characterized by Proterozoic metamorphic and igneous rocks dating back to 1.37 billion years ago, is encircled by Paleozoic and Mesozoic sedimentary rocks. To the southeast of the Llano Uplift lies the Balcones Fault Zone (BFZ), an extensional structural system of mostly normal faults that delineates the transition between Paleozoic-Mesozoic sedimentary rocks and Cenozoic sedimentary cover, which are influential to the regional hydrogeology. This study investigates the hydrogeological dynamics …

Using 3-Dimensional Mapping To Determine The Possibility Of Structural Control On Development Of The Upper Ordovician Lexington Limestone, Central Kentucky, U.S.A., Sean Davis

Theses and Dissertations--Earth and Environmental Sciences

The upper Lexington Limestone of Late Ordovician age has been interpreted to represent a structurally controlled, complex, facies mosaic. This facies mosaic has historically been interpreted to be a carbonate buildup of shoal complexes with interbedded shale units with intertonguing facies. Due to relatively recent advances in geographic-information-systems (GIS) mapping technologies, it is possible to generate three-dimensional (3-D) compatible maps to offer insight to the complexities of the upper Lexington Limestone and to determine if structural control affected the distribution of members. The resulting two-dimensional (2-D) and 3-D maps show that basement faults likely exerted a significant influence on facies …

Structural History Of The Formidable-Le Conte Mountain Area, North Cascades, Wa, Nyle Weldon

WWU Graduate School Collection

A record of Permian to Tertiary polyphase deformation, metamorphism and magmatism is preserved in the Cascades River region of the North Cascades Crystalline Core, Washington. The tectonic history recorded here can be used to understand the deep crustal processes occurring within active convergent plate margins around the world. New structural and geochronologic data from this study are used to advance our understanding of terrane origin, accretion, and processes that altered and thickened the crust of the North Cascades.

The study focuses on several rock units within an accreted Permian-Jurassic island arc, the Chelan Mountains terrane, that was tectonized in Cretaceous …

Structural History Of The Bald Mountain Mining District, Nevada, Usa, David Paul Ryan

WWU Graduate School Collection

The Bald Mountain Mining district, like much of central Nevada, has experienced a complex deformation history. The mining district is considered here as a southern extension of the well-studied Carlin trend of gold deposits to the north. In order to gain a better understanding of how the Bald Mountain Mining District structural style relates to other structural models developed to the north in the Carlin trend, I completed a mapping and structural domain analysis in the district, with a focus on the North Mooney basin area where a high spatial concentration of Carlin-type gold deposits occur. The identification of structural …

Crustal And Upper Mantle Structure Beneath The Southeastern United States From Joint Inversion Of Rayleigh Wave Dispersion And Receiver Functions, Qiuyue Yang

Doctoral Dissertations

"In spite of numerous geophysical investigations have been conducted in southeastern United States, the structure and evolution of the crust and lithospheric mantle remain controversial due the thick sedimentary covers atop the crust of the coastal plains there. In this study, we use data from 186 broadband seismic stations belonging to the USArray Transportable Array to construct a 3-D shear wave velocity model for the southeastern United States for the top 180 km by a joint inversion of Rayleigh wave phase velocity dispersion and receiver functions. Our results show a clear spatial correspondence with major surficial geological features. A prominent …

Delineating Of The Utica Shale/Point Pleasant Formation Play System To Determine Influence Of The Precambrian Basement In Northeastern Ohio, Jarrod R. Bridges

Electronic Theses and Dissertations

The Utica Shale/Point Pleasant Formation system has recently become a highly developed unconventional target for oil and natural gas production, leading to an increased desire for knowledge of the controls on deposition of this system. Precambrian basement features have long been known to affect deposition of older strata near these features across Ohio, but the effects of far field tectonics is not fully agreed upon. Precambrian faults and lineaments are known to exist and have been mapped, but are thought to have ceased their influence on deposition by the time of the Knox unconformity during the Cambrian. In the case …

Micro- To Macro-Scale Structural And Lithological Architecture Of Basal Nonconformities: Implications For Fluid Flow And Injection Induced Seismicity, Garth Hesseltine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rising incidents of earthquakes caused by human activity in the United States, known as induced earthquakes, is a growing concern. Induced earthquakes may occur when fluid and/or wastewater is injected several kilometers beneath the Earth’s surface into sedimentary rocks. Fluids and pressures can migrate from the sedimentary rocks, which are typically friendlier to fluid flow, into underlying less friendlier crystalline rocks along fluid pathways weakening and possibly reactivating preexisting faults. Understanding potential fluid pathways and/or barriers from the sedimentary rocks to crystalline rocks is crucial. I investigate the structure, composition, and heterogeneity of rocks near the contact between the sedimentary …

Characterizing The Deformation History Of The Southern Mina Deflection: Field And Structural Studies In The Huntoon Mountains, California-Nevada, Joseph Bodie Mccosby

All Master's Theses

New geologic mapping and structural studies in the Huntoon Mountain area (HMA), California-Nevada document the volcanic and deformation histories across the south-central Mina Deflection (MD). Our work allows us to (a) test whether present-day GPS predicted sinistral slip rates are the same as geologic slip rates in the southern MD, and (b) determine the kinematics of fault slip is transfer through the MD. The HMA exposes primarily Miocene andesitic-dacitic volcanic rocks overlain by the 12.114 ± 0.006 Ma (⁴⁰Ar/³⁹Ar sanidine, Petronis et al., 2019) Tuff of Jack Spring and the 11.399 ± 0.041 Ma (^{40 …}

Application Of Lidar To 3d Structural Mapping, Bertrand Gaschot

Graduate Theses, Dissertations, and Problem Reports

The rugged, densely forested terrain of the West Virginia Appalachian Valley and Ridge Province has made it difficult for field-based studies to agree on the structure of the highly deformed Silurian-Devonian cover strata. In this study, we demonstrate a 3D approach to geologic mapping utilizing the structural information revealed in a “bare-earth” 1-m Lidar DEM of the Smoke Hole Canyon. The completed 3D map was integrated with kinematic forward modeling carried out in MOVE^TM to provide information on the parameters required to form the major structures observed. Additionally, land surface attributes generated using geomorphometric analysis of the Lidar allowed …

Structural Geology Of The Caddo Gap Area, Ouachita Mountains, Arkansas, Martin Messmer

Electronic Theses and Dissertations

The Caddo Gap quadrangle is located on the southern margin of the Benton Uplift, the orogenic core of the Ouachita Mountains. Recent field mapping focused on delineating stratigraphic and structural relationships in the southern part of the quadrangle to improve existing reconnaissance-scale maps of the area. New structures were discovered that provide further information about the structural evolution of the Ouachita fold and thrust belt.

Field work included mapping the three informal members (Lower, Middle and Upper) of the Arkansas Novaculite. Major folds within the study area include the Nelson Mountain Anticline and two synclinal folds (“South Caddo Mountain” and …

Spatial And Temporal Characterization Of The Petrified Springs Fault, Central Walker Lane, Nevada: Documenting Middle Miocene Dextral Slip, Andrew Hoxey

All Master's Theses

The Central Walker Lane, NV is an active dextral shear zone superimposed on the western boundary of the Basin and Range extensional province. Approximately 25% of dextral shear along the Pacific-North American plate boundary accommodated in the Walker Lane, a NW-striking, intracontinental dextral fault system in eastern California- western Nevada. In the Central Walker Lane, shear is accommodated on five major NW- striking faults, one of which is the Petrified Springs fault, with poorly constrained slip magnitudes, slip rates, and initiation ages. We completed new detailed geologic mapping, combined with structural studies, and ⁴⁰Ar/³⁹Ar geochronology document offset …

Miocene-Pliocene(?) Folds, Normal Faults And The Left-Lateral Buckhorn Fault With Regional Implications, Pahranagat Shear Zone, Nevada, Thomas Godfrey Price

UNLV Theses, Dissertations, Professional Papers, and Capstones

Strike-slip faults play an important role in the development and evolution of extensional regimes including in the intraplate extension in the Basin and Range province. The Basin and Range province is divided into the Northwestern, Northern, Central and Southern Basin and

Range subprovinces. The boundary zone between the Northern and Central subprovinces is marked by several left-lateral fault zones, including the Pahranagat Shear Zone (PSZ), Caliente-Enterprise Zone and Rock Valley Fault Zone. The PSZ has a close spatial and kinematic relationship with the left-lateral Caliente-Enterprise Zone, which lies to the NE, and a slightly more distal relationship to the left-lateral …

Seismic Reflection Profiling Near Middletown, Ohio And Interpretation Of Precambrian Deformational Settings, David Joseph Peterman

Browse all Theses and Dissertations

The reprocessing of four vibroseis seismic reflection lines at the AK Steel facility in Middletown, Ohio, provides new insight on the age, deposition, and structural deformation of the pre-Mount Simon sedimentary sequence below Butler and Warren Counties. Processing was focused on the pre-Mt. Simon reflections to reveal gently west-southwest dipping reflectors that make a slight angular unconformity with the overlying Paleozoic sedimentary strata. This pre-Mount Simon sedimentary sequence has been encountered in several wells from western Ohio, Indiana, and northern Kentucky and has been identified as the Middle Run Formation. Examination of the weak and discontinuous seismic character of the …

Understanding The Contractional History Of Surprise Canyon, California Through Digital Field Mapping, 3d Modeling, And U-Pb Zircon Geochronology, Joshua A. Cobb

Open Access Theses & Dissertations

Detailed digital mapping of lower-middle Surprise Canyon has revealed a more complex structure than previously interpreted. Rock units derived from the metamorphosed equivalents of the Pahrump Group exposed in Surprise Canyon display juxtapositions inconsistent with stratigraphic variations suggested in previous studies. This study proposes a contractional history of the central Panamint Mountains defined by two kinematically distinct and geochronologically constrained deformation events. D1 is characterized by a shallow dipping, NNW striking L and LS tectonite fabric ubiquitously observed in all metasedimentary and basement units. F1 folds are mesoscopic in scale and isoclinal with an axial planar S1 foliation. A prominent …

Normal Fault Block Or Giant Landslide? Baldy Block, Wasatch Range, Utah, Eric R. Meyer

Theses and Dissertations

Understanding the interplay between surficial and tectonic processes in the development of Utah's Wasatch Range is vital to evaluating geologic hazards along the Wasatch Front. Baldy is a large (6.125 km3) block of limestone and sandstone structurally overlying shale on the western flank of Mount Timpanogos. It has been mapped as a downdropped normal fault block of Permian units, but no other trace of such a fault exists along the range. The Baldy block structurally overlies the weak Manning Canyon shale, which has produced a regional geomorphology replete with faceted spurs, landslide scarps and deposits. Structural, bio- and litho-stratigrahic mapping …

Structural And Geochronologic History Of Southern Alaskan Blueschists, Erik M. Day

Open Access Theses & Dissertations

Detrital zircon data are presented from the Liberty Creek blueschist in the central Chugach Mountains which indicate two distinct periods of the preservation of blueschist facies metamorphism along the southern Alaskan margin. A maximum depositional age of ~136 Ma demonstrates that the Liberty Creek schist was deposited long after the Jurassic cooling ages (196-185 Ma; Lopez-Carmona et al., 2011) recorded in western Alaskan blueschist bodies, revealing two blueschist preservation events. This Early Cretaceous depositional age also indicates that there have been major reorganizations within this subduction complex because the Potter Creek assemblage, directly south of the Liberty Creek schist, is …

Integrated Geophysical Exploration Of A Known Geothermal Resource: Neal Hot Springs, Clinton Ryan Colwell

Boise State University Theses and Dissertations

I present an integrated geophysical characterization of the Neal Hot Springs geothermal system in eastern Oregon. This newly established 23 MW geothermal production site is located in a region of complex geology and intersecting faults associated with two major extensional systems; the Oregon-Idaho Graben and the western Snake River Plain. The intersection of two dominant fault orientations, coupled with a high geothermal gradient from relatively thin continental crust and radioactive decay from a shallow granitic body, produces the pathways and heat needed for deep water circulation at Neal Hot Springs. New geologic mapping, geochemistry, and measurements from several boreholes in …

Age, Provenance, And Structure Of The Weatherby Formation, Eastern Izee Sub-Basin, Blue Mountains Province, Oregon And Idaho, Bryant Douglas Ware

Boise State University Theses and Dissertations

The terranes of the Blue Mountains province of eastern Oregon and west-central Idaho provide an important link between the geology of the North American Cordillera exposed in Canada and Alaska in the north and Nevada and California in the south. The Izee basin is a volcanic-rich sedimentary sequence onlapping the volcanic arc and accretionary mélange terranes of the Blue Mountains, and comprises the marine flysch Weatherby Formation at its eastern extent. This study sought to establish the stratigraphic and structural relationships between the Weatherby Formation and the proximal Baker and Olds Ferry terranes. Small-scale mapping, structural measurements, and geochronological data …

Rock Properties And Structure Within The San Andreas Fault Observatory At Depth (Safod) Borehold, Northwest Of Parkfield, California: In Situ Observations Of Rock Deformation Processes And Fluid-Rock Interactions Of The San Andreas Fault Zone At ~ 3 Km Depth, Kelly Keighley Bradbury

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The San Andreas Fault Observatory at Depth (SAFOD) is a scientific drilling experiment situated along the central creeping segment of the San Andreas Fault, near Parkfield, California, and north of a segment of the fault that has experienced large historical earthquakes. Drilling into active fault zones allows scientist’s to examine in situ rock samples and to record real-time data.

The main goal of this study is to characterize the geologic setting and rock properties of the San Andreas fault at ~ 3 km depth in the SAFOD borehole. In this region, the fault deforms nearly continuously through aseismic creep and …

Structural Analysis Of The Central Ibex Hills, Death Valley, California, Oscar Esparza

Open Access Theses & Dissertations

The Ibex Hills, in southern Death Valley, California, are composed mainly of Late Proterozoic sedimentary rocks overlying middle Proterozoic basement that are complexly deformed by Mesozoic contractional structures overprinted by Neogene extensional/transtensional structures. Detail mapping of the Ibex Hills reveals evidence of several deformational events. Brittle deformation of both extensional and strike-slip origin are recognized throughout the mapped area, but the main structure identified is a low angle fault at the base of the Noonday Dolomite, Sentinel Peak member, herein called the Noonday Fault. This low angle fault is dipping toward the east-northeast and has a curved geometry that resembles …

Bedrock Geology And Tectonic Evolution Of The Western Central Maine Zone, South Central Massachusetts, Thomas Bradley Walker

Theses and Dissertations--Earth and Environmental Sciences

Bedrock geology of the East Brookfield quadrangle (EBQ), based on new 1:24000 scale mapping, consists of an interfolded sequence of Rangeley Fm. and Paxton Fm. metasediments, intruded by Early Mississippian tonalitic to granitic orthogneisses and underlain in the western half by folded orthogneisses of unknown age. Pervasive flattening strains have created planar, generally NNE-SSW striking and consistent moderately west dipping foliations. Generally strike-parallel stretching lineations and boudinage structures, with rarer dip parallel stretching lineations, reflect extrusion of CMZ metasediments and orthogneisses with a flattening component. Mapping in the EBQ demonstrates that a transition between deformational mechanisms of the southern Central …

Testing Models Related To The Laramide Uplift Of The Uinta Mountains And Geologic Mapping Of The Jessen Butte 7.5 Minute Quadrangle, Dagget County, Utah And Sweetwater County, Wyoming, Coreen Hurst

Theses and Dissertations

Geologic mapping of the Jessen Butte 7.5 minute quadrangle and the gathering of structural data throughout the quadrangle was used to determine the paleostress regime during the Laramide Orogeny along the north flank of the Uinta Mountains. The Henrys Fork thrust fault and the Uinta thrust fault are major north bounding faults and within the Jessen Butte quadrangle these faults transfer deformation from one to the other. The Jessen Butte thrust fault is a fault splay that splits off from the Henrys Fork thrust fault. Complex fold geometries were created by the interaction of the faults. Bedding plane orientation, mode …

Volcanological And Petrogenetic Characteristics Of Komatiites Of The 3.3 Ga Saw Mill Complex, Weltevreden Formation, Barberton Greenstone Belt, South Africa, Matthew Stephen Huber

LSU Master's Theses

The Saw Mill Complex (SMC) is a 1275 m thick layered komatiitic sequence in the 3.3 Ga Weltevreden Formation, uppermost stratigraphic unit of the Onverwacht Group in the northern part of the Barberton Greenstone Belt, South Africa. A series of ultramafic complexes in the Weltevreden Formation have been interpreted as layered ultramafic intrusions, consisting of thick, layered ultramafic units of peridotite, pyroxenite, dunite, and gabbro. However, recent work on the Pioneer complex of the Weltevreden Formation has demonstrated an extrusive origin of komatiites and tuffs. The Weltevreden Formation has been less studied than other Onverwacht Group units. It is likely …

Internal Structure And Geochronology Of The Gerrei Unit In The Flumendosa Area, Variscan External Nappe Zone, Sardinia, Italy, Ashley V. Dack

Boise State University Theses and Dissertations

To investigate the stratigraphy and structural evolution of the Variscan Orogen of the External Nappe Zone, Sardinia, Italy, field work and geochronologic analyses were combined to assess both regional and orogen scale issues. Geologic mapping, structural analysis, and sampling in the Flumendosa area coupled with high-precision U-Pb zircon geochronology were used to determine the duration of Ordovician magmatic activity and the structural evolution of the Variscan Orogen.

To constrain the duration of magmatism for the Flumendosa area, U-Pb ID/TIMS zircon analyses were performed on samples from a lower volcanic flow of the Ordovician Volcanic Unit and an upper, syn to …

Origin And Tectonic Evolution Of Gondwana Sequence Units Accreted To The Banda Arc: A Structural Transect Through Central East Timor, Elizabeth Anick Zobell

Theses and Dissertations

Petrographic and age analysis of sandstones, detailed structural analysis and gravity modeling were conducted to investigate the origin of the Gondwana Sequence in the Timor Region, and to better constrain the tectonic evolution of the active Banda Arc. Our field studies and U/Pb zircon age analysis helped assign most units to either Asian or Australian affinity. Detrital zircon from uplifted Banda forearc units (Asian affinity) have U/Pb ages as young as 80 Ma (Standley and Harris, in press). In contrast, analysis of detrital zircon from Gondwana Sequence sandstones accreted to the Banda Arc from Savu to East Timor are no …

Banda Forearc Metamorphic Rocks Accreted To The Australian Continental Margin: Detailed Analysis Of The Lolotoi Complex Of East Timor, Carl Eldon Standley

Theses and Dissertations

Petrologic, structural and age investigations of the Lolotoi Complex of East Timor indicate that it is part of a group of thin metamorphic klippen found throughout the region that were detached from the Banda forearc and accreted to the NW Australian continental margin during Late Miocene to Present arc-continent collision. Metamorphic rock types are dominated by (in order of greatest to least abundance), greenschist, graphitic phyllite, quartz-mica schist, amphibolite and pelitic schist. Mineral, whole rock, and trace element geochemical analyses of metabasites indicate that protolith compositions are consistent with tholeiitic basalt and basaltic andesite with mixed MORB and oceanic arc …

Structure And Petrology Of Tertiary Volcanic Rocks In Parts Of Toms Cabin Spring And Lucin Nw Quadrangles (Box Elder Co.), Utah, Bruce Edward Scarbrough

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A series of late Tertiary rhyolitic and dacitic flows, domes, and minor pyroclastic rocks form an elongate volanic mass along the northwestern Utah-northeastern Nevada border. The structure of the flow banding and the linear arrangement of vents indicate that the mass represents a multi-sourced extrusive complex which erupted through many fissure-type conduits. A 39 km² area at the southern end of the mass was studied in detail in order to gain a better understanding of the eruptive nature and history of these Tertiary volcanic rocks. Age dating reveals that volcanism in the study area was episodic, and covered a …

Structure And Petrography Of The Tertiary Volcanic Rocks Between Death Creek And Dairy Valley Creek (Box Elder Co.), Utah, E. Matthew Hare

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several volcanic flows lie between Death Creek and Dairy Valley Creek, near Etna, Utah. The major, central portion of the volcanic flows is composed of dacite and dacite vitrophyre. An elongate ridge in the southeastern corner of the study area and several small outcrops in Death Creek Valley are composed of rhyolite and rhyolite vitrophyre. Additional rock types include conglomerate, volcanic ash, and tuffaceous sedimentary rock of the Tertiary Salt Lake Formation, Paleozoic limestone, and Tertiary basalt.

Dacite and dacite vitrophyre samples are porphyritic, containing phenocrysts of plagioclase, quartz, biotite, amphibole, orthopyroxene, and iron-titanium oxides. Rhyolite and rhyolite vitrophyre samples …

Structure And Petrology Of Tertiary Volcanic Rocks Near Etna, Utah, Kent W. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three volcanic domes and related volcanic rocks of Tertiary age are located near Etna, Utah, in Box Elder County. The domes follow a north-south trend and are fault controlled. Flow structure indicates a change from a less viscous, flow-forming lava which produced an exogenous dome to a more viscous lava which formed endogenous domes. Associated pyroclastic deposits are negligible. The volcanic rocks are composed of porphyritic rhyolite and rhyolitic vitrophyre having phenocrysts of quartz, sanidine, plagioclase and biotite with minor amounts of Fe-Ti oxides, hypersthene, allanite and calcic amphibole. Quartz and sanidine phenocrysts are generally embayed whereas plagioclase phenocrysts are …

Structural Geology Of The Southern Part Of Elkhorn Mountain, Bannock Range, Idaho, George A. De Vries

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The area of southern Elkhorn Mountain, a previously unmapped area, is located north of Malad City, Idaho, in the Bannock Range. The mapped area is within the Basin and Range province. The mapped area measures 5.9 miles in the north-south direction and approximately 8.8 miles in the east-west direction.

The oldest stratigraphic unit, in the mapped area, is the Ute Formation of Middle Cambrian age. Other units of Cambrian age, in ascending order, are: Blacksmith Formation, Bloomington Formation, Nounan Formation, and St. Charles Formation. The units of Ordovician age are the Garden City and the Swan Peak Formations. The youngest …