Tectonics and Structure Commons^™

Quantifying Tekeze River Canyon Incision On The Ethiopian Plateau From Low-Temperature Apatite Thermochronology, Jacob Thomas Grigsby

Masters Theses & Specialist Projects

The Ethiopian Plateau in East Africa features dynamic topography, deep river incision (~1.5 km), active tectonics, continental rifting, volcanic terrain and ~2 km of plateau uplift. Situated on the northwestern part of the Ethiopian Plateau, the Tekeze River is one of the two major rivers associated with incising and documenting the recent geologic history of the uplifted plateau landscape. The consequential Tekeze River incision into the uplifted Ethiopian Plateau is associated with the arrival and impingement of the Afar mantle plume as evidenced by the presence of thick sheets of Cenozoic flood basalts (~30 Ma). However, the Cenozoic to present-day …

A Micromechanics-Based Multiscale Approach Toward Continental Deformation, With Application To Ductile High-Strain Zones And Quartz Flow Laws, Xi Lu

Electronic Thesis and Dissertation Repository

Earth’s lithosphere may be regarded as a composite material made of rheologically heterogeneous elements. The presence of these heterogeneous elements causes flow partitioning, making the deformation of Earth’s lithosphere heterogeneous on all observation scales. Understanding the multiscale heterogeneous deformation and the overall rheology of the lithosphere is very important in structural geology and tectonics. The overall rheology of Earth’s lithosphere on a given observation scale must be obtained from the properties of all constituents and may evolve during the deformation due to the fabric development. Both the problem of flow partitioning and characterization of the overall rheology are closely related …

Late Cretaceous Stratigraphy And Paleoceanographic Evolution In The Great Australian Bight Basin Based On Results From Iodp Site U1512, K. G. Macleod, Lloyd T. White, Carmine C. Wainman, Mathieu Martinez, Matthew M. Jones, Sietske J. Batenburg, Laurent Riquier, Shannon J. Haynes, David K. Watkins, K. A. Bogus, H.-J. Brumsack, R. Do Monte Guerra, Kirsty M. Edgar, Trine Edvardsen, Dennis Harry, Takashi Hasegawa, R. W. Hobbs, Brian T. Huber, T. Jiang, J. Kuroda, E. Y. Lee, Yong-Xiang Li, Alessandro Maritatai, Lauren K. O'Connor, Maria Rose Petrizzo, Tracy M. Quan, C. Richter, Maria Luisa Garcia Tejada, G. Tagliaro, Erik Wolfgring, Zhaokai Xu

Department of Earth and Atmospheric Sciences: Faculty Publications

The Upper Cretaceous sedimentary sequence at International Ocean Discovery Program Site U1512 in the Ceduna Sub-basin of the Great Australian Bight represents a continuous, N 690 m thick interval of black silty clay and claystone spanning the lower Turonian through Lower Campanian (~10 million years). Sediments were deposited in an elongate, ~E-W oriented, ~2500 km long rift system that developed between Australia and Antarctica with an open-ocean connection to the west and a continental bridge to the east. Site U1512 cores provide a unique, continuous record of Late Cretaceous deposition in the Ceduna Sub-basin on the hanging wall of the …

Microwave Brightness Temperature Characteristics Of Three Strong Earthquakes In Sichuan Province, China, Feng Jing, Ramesh P. Singh, Yueju Cui, Ke Sun

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Passive microwave remote sensing technology is an effective means to identify the thermal anomalies associated with earthquakes due to its penetrating capability through clouds compared with infrared sensors. However, observed microwave brightness temperature is strongly influenced by soil moisture and other surface parameters. In the present article, the segmented threshold method has been proposed to detect anomalous microwave brightness temperature associated with the strong earthquakes occurred in Sichuan province, China, an earthquake-prone area with high soil moisture. The index of microwave radiation anomaly (IMRA) computed by the proposed method is found to enhance prior to the three strong earthquakes, 2008 …

Comparisons Between Tethyan Anorthosite-Bearing Ophiolites And Archean Anorthosite-Bearing Layered Intrusions: Implications For Archean Geodynamic Processes, Ali Polat, Paul Sotiriou

Earth & Environmental Sciences Publications

Elucidating the petrogenesis and geodynamic setting(s) of anorthosites in Archean layered intrusions and Tethyan ophiolites has significant implications for crustal evolution and growth throughout Earth history. Archean anorthosite-bearing layered intrusions occur on every continent. Tethyan ophiolites occur in Europe, Africa, and Asia. In this contribution, the field, petrographic, petrological, and geochemical characteristics of 100 Tethyan anorthosite-bearing ophiolites and 155 Archean anorthosite-bearing layered intrusions are compared. Tethyan anorthosite-bearing ophiolites range from Devonian to Paleocene in age, are variably composite, contain anorthosites with highly calcic (An_44-100) plagioclase and magmatic amphibole. These ophiolites formed predominantly at convergent plate margins, with some …

Testing Interpretations Of The Displacement Magnitude Of The Teton Fault And Uplift Of The Teton Range, Wyoming With Integrated Flexural-Kinematic And Thermal Modeling, Autumn Helfrich

Theses and Dissertations--Earth and Environmental Sciences

The Teton fault is a range-front normal fault in northwestern Wyoming. Previous estimates of the maximum displacement (D_max) on the Teton fault cover a wide range (2 - 11 km). Discrepancies also exist regarding the slip onset timing, which spans 2 - 13 Ma. To address these discrepancies, the exhumation history of the Teton Range is here investigated using forward flexural-kinematic (Move) and thermal-kinematic (Pecube) models that can be compared with previously reported apatite fission track (AFT) and apatite (U-Th)/He (AHe) ages from Mount Moran, which has been previously hypothesized to represent the …

Spatially Variable Syn- And Post-Orogenic Exhumation Of The Appalachian Mountains From Apatite And Zircon (U-Th)/He Thermochronology, Luke Coughtry Basler

Honors Projects

We present zircon and apatite (U-Th)/He (ZHe, closure temperature = 150-200ºC; AHe, closure temperature = 45-80ºC) results from two study regions in the Appalachians Mountains to investigate the timing, rates, and spatial trends of exhumation during Alleghanian orogenesis, Atlantic rifting, and post-rift passive margin conditions. Within West Virginia and Virginia, 10 ZHe dates along an across-orogen transect display an eastward younging trend, from ~425 million years (Ma) in the western Appalachian Plateau province, to ~250-300 Ma in the central Valley-Ridge fold-thrust belt, and 163 ± 29 Ma in the eastern Piedmont. Inverse thermal modeling of ZHe data using external geologic …

Reconstruction Of The 2018 Anak Krakatau Collapse Using Planetscope Imaging And Numerical Modeling, Davide Saviano

Dissertations, Master's Theses and Master's Reports

The study was focused on the Anak Krakatau sector collapse that occurred on 22 December 2018 in the Sunda Strait (Indonesia). The goal of the study was to monitor and analyze changes of the volcanic edifice and to try to understand causes that may have predisposed and triggered the sector collapse.

The use of different remote sensing techniques allowed the acquisition of thermal data, SO₂ emission data, structural data and the identification and analysis of the eruptive events that occurred on Anak Krakatau in the period from 1° January 2016 to 28 February 2019. The acquisition of 1221 thermal …

Documenting The Earthquake History Of The Thousand Springs Fault In Summer Lake Basin, Oregon, Usa, Elizabeth Curtiss

All Master's Theses

Defining seismic hazards in low-strain-rate regions such as the northwestern Basin and Range can be difficult due to the infrequency of earthquakes. Revealing the earthquake records of low-strain-rate regions can refine our understanding of the variability of earthquake sizes and recurrence intervals, however, which can ultimately improve hazard analysis. Four active normal faults form the Summer Lake basin, in the northwestern Basin and Range: The Thousand Springs (TSF), Ana River (ARF), Slide Mountain, and Winter Ridge faults. Other than the TSF, the faults in the Summer Lake basin have documented histories that include surface-rupturing (>M6) earthquakes. Scarps along the …

Mapping And Modeling The Seattle Fault Tsunami Inundation In Puget Sound, David Bruce

All Master's Theses

Coastal communities of Puget Sound are susceptible to tsunami inundation from multiple sources. Two sources of potential tsunami hazard that threaten the region are earthquakes on crustal faults in the Puget Lowlands, or earthquakes originating on the Cascadia subduction zone. This study investigated two coastal marshes in Puget Sound, Deer Lagoon and Doe-Kag-Wats, for evidence of a paleotsunami record to combine with tsunami modeling, in order to predict how future events could inundate Puget Sound. A deposit, interpreted as a paleotsunami, is traceable thought the marsh stratigraphy near the modern day tidal inlet of Deer Lagoon, a site that has …

Applying Garnet And Zircon Ree Linkages To Determine Timing Of P-T Conditions And Tectonic Implications For Uhp Eclogites And Hp Granulites, Dulan Uhp Terrane, China, Wesley Weisberg

All Master's Theses

The Dulan ultrahigh-pressure (UHP) terrane in western China hosts rocks that record continental collision, however; the timing of peak P-T conditions in UHP eclogites and HP granulites, and the tectonic significance of their spatial relationship within the Dulan UHP terrane are not well understood. This study, (1) evaluates rare earth element (REE) equilibrium between garnet and zircon, to assess coeval growth; (2) links timing (from zircon) to the P-T history (from garnet) to constrain the P-T-t path of the Dulan UHP terrane and interpret implications for zircon growth; (3) refines P-T conditions for HP granulite; and (4) evaluates the tectonic …

Syn-Sedimentary Tectonic Markings In The Oligocene Datça-Kale-Acı Göl Basin, Western Anatolia, Gülşen Elmas, Gürol Seyi̇toğlu, Nizamettin Kazanci, Veysel Işik

Bulletin of the Mineral Research and Exploration

In southwest Turkey, the Oligocene sedimentary sequence is located on the Datça-Kale-Acı Göl basin between the Menderes Massif and Lycian nappes. To understand the nature of this basin is important for tectonic models that explain the exhumation of the Menderes massif. In the northeast extension of this basin, the sedimentary sequence is interpreted as alluvial fan, fan-delta, beach, marine input, inner shelf carbonates and offshore deposits. The Oligocene Datça-Kale main breakaway fault bounding the south eastern margin of the basin is represented by İnceler and Acı Göl faults in the study area. The wedge geometry of the sequence thickening towards …

Major Lower Paleozoic Horizons Of The Southern Illinois Basin, John B. Hickman

Report of Investigations--KGS

The geology exposed at the surface in the southern Illinois Basin has been mapped in great detail by countless workers over the past century. With the exception of limited and scattered exposures in incised river valleys, the oldest rocks exposed outside of the Jessamine, Nashville, and Ozark Domes surrounding the Illinois Basin are Mississippian in age. Extensive deposits of Cambrian–Devonian sediments occur in the subsurface above crystalline basement in this region, however. All available data for the region were analyzed to produce a single, comprehensive set of interpretations. The data used in this study include 1:24,000-scale geologic quadrangle maps, oil …

Quantification Of Surface Roughness Of Lava Flows On Mars, Carolina Rodriguez Sanchez-Vahamonde

Electronic Thesis and Dissertation Repository

Volcanism has played a significant role throughout Mars’ geologic history. Extensive lava flows are widely spread across Mars’ equatorial region, shaping the surface in a very distinct way. In radar images (at the decimeter scale), these flows are bright, which is a typical characteristic of extremely rough, blocky lavas flows seen on Earth. Although the source of the extreme roughness of Martian lava flows is unknown, their surface roughness parameters can be constrained to 1) gain information about Mars’ interior processes, 2) find appropriate analogues on other planetary bodies, and 3) ideally infer the emplacement style of such lavas. Here, …

Crustal Structure Beneath The East Coast Magnetic Anomaly From Seismic Refraction Tomography, Collin C. Brandl

Earth and Planetary Sciences ETDs

Syn-rift igneous addition is necessary for successful continental breakup. Past investigations of passive margins have focused on strike perpendicular structure, but potential field anomalies indicate that significant crustal variations may be present. Data from 21 ocean bottom seismometers was acquired as part of the Eastern North American Margin Community Seismic Experiment and was used for tomographic inversion to create 2D velocity models of the margin that are representative of crustal structure. Crustal thickness varies along-strike from ~20 km to ~24 km and a high velocity (Vp > 7 km/s) layer is present at the base of the crust above the Moho. …

Paleoseismology Of The Central Garlock Fault In Searles Valley, California, Kyle Pena

Electronic Theses, Projects, and Dissertations

In this study, a paleoseismic trench with limited age constraints that was previously excavated in 1990 across the central Garlock Fault near Christmas Canyon, in Searles Valley, California, was reopened to take advantage of new advances in luminescence dating techniques to investigate potential temporal variability in earthquake recurrence on the Garlock fault and to analyze previously unexposed older earthquake evidence. The trench exposed interbedded alluvial sand and pebble-gravels, with well-sorted, rounded, lacustrine sand from the most recent highstand of pluvial Lake Searles present at the base of the trench. Preliminary findings suggest at least 10 surface rupturing earthquake events occurred …

Improving Earthquake Disaster Models With Post-Event Data: Insights From The 2015 Gorkha, Nepal Earthquake, Bradley Steven Wilson

Graduate Theses and Dissertations

Immense amounts of data are collected following earthquake disasters. Yet, it remains unclear how researchers’ might take full advantage of diverse post-disaster datasets. Using data from the 2015 Gorkha Nepal earthquake, this dissertation explores three ways in which post- disaster survey and assessment datasets can be used to inform models of seismic risk, vulnerability, and recovery processes. The first article presents an empirical analysis of scale issues in disaster vulnerability indices using a novel dataset of 750,000 households. This study finds that using aggregated household data to create social vulnerability indices can produce results that are meaningfully different from equivalent …

Reinterpreting The Tectonic Model Of The Southern Part Of The Taconic Orogeny Through A Provenance Study Of Late Ordovician Sandstones, Juan Carlos Guerrero

LSU Master's Theses

A provenance study of quartz arenites that stratigraphically are closely associated with major Ordovician K-bentonites has been conducted in order to further our understanding of the tectonic setting of eastern Laurentia during the Late Ordovician. Using laser ablation ICP-MS, detrital zircons separated from Ordovician sandstone samples in the southeastern Appalachian Mountains (Virginia to Alabama) were dated using U-Pb geochronology. Analytical results show three dominate age ranges for the zircons from these sandstones: ~440-490 Ma, ~900-1300 Ma, and ~1300-1500 Ma. In addition, some zircon ages grouped into older ranges of ~1600-1800 Ma, ~1800-1900 Ma, and ~2600-2800 Ma. Zircon ages from ~900-2800 …

Statistical Modeling And Characterization Of Induced Seismicity Within The Western Canada Sedimentary Basin, Sid Kothari

Electronic Thesis and Dissertation Repository

In western Canada, there has been an increase in seismic activity linked to anthropogenic energy-related operations including conventional hydrocarbon production, wastewater fluid injection and more recently hydraulic fracturing (HF). Statistical modeling and characterization of the space, time and magnitude distributions of the seismicity clusters is vital for a better understanding of induced earthquake processes and development of predictive models. In this work, a statistical analysis of the seismicity in the Western Canada Sedimentary Basin was performed across past and present time periods by utilizing a compiled earthquake catalogue for Alberta and eastern British Columbia. Specifically, the frequency-magnitude statistics were analyzed …

Application Of 3d Salt Modeling: An Example From The Northeastern Gulf Of Mexico, Adam Mattson

Masters Theses & Specialist Projects

Salt tectonics has important implications for hydrocarbon exploration in saltbearing basins since salt deformation can directly or indirectly form hydrocarbon traps, influence hydrocarbon migration, and can control deepwater depositional systems. In various basins around the globe, extensive research has been conducted on initiation of salt mobilization, subsequent deformation, and eventual cessation, mostly from subsurface two-dimensional (2D) sections. However, 3D seismic data has dominated the petroleum industry for the last 30 years. Despite the plethora of 3D seismic data acquired in salt-bearing basins, there has been hardly any published work on the 3D geometries of complex salt bodies. 3D salt mapping …