Unmasking A Terrane Triple Point In Central Virginia, 2020 William & Mary
Unmasking A Terrane Triple Point In Central Virginia, Ryan Walter
Undergraduate Honors Theses
The central and southern Appalachian Piedmont contains terranes with both Laurentian and Gondwanan affinities that were amalgamated during a series of Paleozoic orogenies. In the southwestern Virginia Piedmont, the Smith River Allochthon (SRA) is interpreted as a peri-Gondwanan or distal Laurentian regional scale thrust sheet of metaclastic and meta-igneous rocks. The SRA was first identified in southern Virginia, and regional-scale maps extend the SRA northeast into the central Virginia Piedmont along the boundary between the Blue Ridge (BR) and western Piedmont (WP). In southern Virginia, the Bowens Creek fault separates the BR from the WP, and regional maps project this ...
Testing A Drone-Based Magnetic Field Surveying System, 2020 University of Nebraska-Lincoln
Testing A Drone-Based Magnetic Field Surveying System, Erik Jacobson, Irina Filina
UCARE Research Products
Aeromagnetic surveys are conducted by geoscientists to study subsurface geologic structures, such as faults. This type of survey uses a magnetometer mounted upon an airborne vehicle to collect magnetic field data. Magnetic anomalies are caused by variations in subsurface geology, namely in magnetic properties of subsurface rocks. Jacobson and Filina (2019) reported on the development of a new low cost drone, based magnetic field surveying system by the UNL Geophysics Team. This drone-based magnetic system is capable of collecting high resolution data at low speeds and low altitudes. The current study focuses on testing this system by conducting two flights ...
Seeing Through The Ottawan Overprint, Adirondack Mtns., Ny: Integrating Microstructural Analysis, Geothermobarometry, And In-Situ Monazite Petrochronology, 2020 University of Massachusetts Amherst
Seeing Through The Ottawan Overprint, Adirondack Mtns., Ny: Integrating Microstructural Analysis, Geothermobarometry, And In-Situ Monazite Petrochronology, Justin Mistikawy
Integrating field observation with petrochronology is critical for understanding the tectonometamorphic evolution of the North American Grenville Province. Despite methodological advances in geothermobarometry and geochronology, incorporating these data into larger models of the Adirondack Mountains remains particularly challenging due to the presence of multiple generations of deformation, primarily related to the ca. 1190 – 1140 Ma Shawinigan and ca. 1090 – 1020 Ma Ottawan Orogenies (McLelland et al.,2013). The Rock and Bear Ponds area is a dome of tight-to-isoclinally folded metapelites in structural contact with orthogneiss. Fold generations are orthogonal and partitioned such that the northern area is dominated by an ...
Characterization Of Magma Storage And Dynamics At Akutan, Semisopochnoi, And Okmok Volcanoes From Analytical And Numerical Models Of Geodetic, Seismic, And Petrologic Data, 2020 Southern Methodist University
Characterization Of Magma Storage And Dynamics At Akutan, Semisopochnoi, And Okmok Volcanoes From Analytical And Numerical Models Of Geodetic, Seismic, And Petrologic Data, Kimberly Degrandpre
Earth Sciences Theses and Dissertations
Volcanic eruptions can cause significant socioeconomic loss, but a better understanding of the processes and dynamics influencing the evolution of volcanic plumbing systems will advance the development of eruption forecasting models that will ultimately mitigate hazards and risks associated with eruptive events. Geologic and geophysical data must be integrated in 3D, finite- element, multiphysical, numerical models to define the coupled evolution of magmatic and crustal stress regimes in volcanic environments, but in data limited regions this is not always an option. The remote nature of the Aleutian Island Arc restricts ground-based monitoring and sampling efforts, and due to sparse temporal ...
A Micromechanics-Based Multiscale Approach Toward Continental Deformation, With Application To Ductile High-Strain Zones And Quartz Flow Laws, 2020 The University of Western Ontario
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 ...
Microwave Brightness Temperature Characteristics Of Three Strong Earthquakes In Sichuan Province, China, 2020 China Earthquake Administration
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 ...
Spatially Variable Syn- And Post-Orogenic Exhumation Of The Appalachian Mountains From Apatite And Zircon (U-Th)/He Thermochronology, Luke Coughtry Basler
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 constraints indicates ...
Reconstruction Of The 2018 Anak Krakatau Collapse Using Planetscope Imaging And Numerical Modeling, 2020 Michigan Technological University
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 ...
Major Lower Paleozoic Horizons Of The Southern Illinois Basin, 2019 University of Kentucky
Major Lower Paleozoic Horizons Of The Southern Illinois Basin, John B. Hickman
Kentucky Geological Survey Report of Investigations
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 ...
Quantification Of Surface Roughness Of Lava Flows On Mars, 2019 The University of Western Ontario
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 ...
Paleoseismology Of The Central Garlock Fault In Searles Valley, California, 2019 California State University, San Bernardino
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 ...
Statistical Modeling And Characterization Of Induced Seismicity Within The Western Canada Sedimentary Basin, 2019 The University of Western Ontario
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 ...
Millard Et Al. Pressure Dependence Of Magnesite Creep 2019 Geosciences.Pdf, 2019 University of Akron
Millard Et Al. Pressure Dependence Of Magnesite Creep 2019 Geosciences.Pdf, Caleb Holyoke
No abstract provided.
Orientation Of Paleostress Of Raplee Ridge Anticline, 2019 Southern Utah University
Orientation Of Paleostress Of Raplee Ridge Anticline, Loren Randall Holyoak, John S. Maclean
The Compass: Earth Science Journal of Sigma Gamma Epsilon
During the Laramide Orogeny several major folds were formed in Southern Utah, one of those being the Raplee Ridge anticline. Raplee Ridge is approximately eight miles from Mexican Hat, Utah. The San Juan River cuts through the anticline, exposing the Honaker Trail Formation’s beds of shale and limestone with chert nodules. Accompanying the mountain-scale ductile deformation of the Raplee Ridge anticline are decimeter-scale brittle conjugate fractures in the limestone’s chert nodules. The objective of this study is to compare the orientation of paleostress that formed the Raplee Ridge anticline with the conjugate fractures within the chert nodules to ...
Gamma Ray And Radon Anomalies In Northern Taiwan As A Possible Preearthquake Indicator Around The Plate Boundary, Ching-Chou Fu, Lou-Chuang Lee, Tsanyao Frank Yang, Cheng-Horng Lin, Cheng-Hong Chen, Vivek Walia, Tsung-Kwei Liu, Dimitar Ouzounov, Gioacchino Giuliani, Tzu-Hua Lai, Peng-Kang Wang
Mathematics, Physics, and Computer Science Faculty Articles and Research
Taiwan is tectonically situated in an oblique collision zone between the Philippine Sea Plate (PSP) and the Eurasian Plate (EP). Continuous observations of gamma rays at the Yangmingshan (YMSG) station and soil radon at the Tapingti (TPT) station were recorded in the volcanic area and around a major fault zone, respectively, in Taiwan for seismic studies. A number of anomalous high gamma ray counts and radon concentrations at certain times were found. It is noted that significant increases of soil radon concentrations were observed and followed by the increase in gamma rays a few days to a few weeks before ...
Fractures, Fluids, And Metamorphism: Shear Zone Initiation In The Marcy Anorthosite Massif, Adirondacks, New York, Usa, James Hodge
Electronic Theses and Dissertations
Localized shear zones are important rheological features that influence deformation behavior throughout the Earth’s middle-to-lower crust. Therefore, the processes through which shear zones initiate and localize remains an important geologic question. The study of strain localization and shear zone initiation is made difficult due to continued deformation overprinting the microstructures which lead to initiation and obfuscating the context in which localization occurred. The Marcy anorthosite in the Adirondack Highlands, New York, is a nominally granulite-facies, plagioclase-rich massif cut by centimeter-to-meter scale shear zones which provides a natural example of shear zone localization within the middle-to-lower crust. My work focuses ...
Machine Learning Predicts Aperiodic Laboratory Earthquakes, 2019 Southern Methodist University
Machine Learning Predicts Aperiodic Laboratory Earthquakes, Olha Tanyuk, Daniel Davieau, Charles South, Daniel W. Engels
SMU Data Science Review
In this paper we find a pattern of aperiodic seismic signals that precede earthquakes at any time in a laboratory earthquake’s cycle using a small window of time. We use a data set that comes from a classic laboratory experiment having several stick-slip displacements (earthquakes), a type of experiment which has been studied as a simulation of seismologic faults for decades. This data exhibits similar behavior to natural earthquakes, so the same approach may work in predicting the timing of them. Here we show that by applying random forest machine learning technique to the acoustic signal emitted by a ...
In-Situ Zircon And Monazite Geochronology From Compositionally Distinct Layers In A Single Migmatitic Paragneiss Sample Located In The Eastern Adirondack Mountains, Ny, 2019 University of Massachusetts Amherst
In-Situ Zircon And Monazite Geochronology From Compositionally Distinct Layers In A Single Migmatitic Paragneiss Sample Located In The Eastern Adirondack Mountains, Ny, Kaitlyn Suarez
Migmatites are a common rock type in the Adirondack Mountains, NY. We analyzed a single sample of biotite-garnet-sillimanite paragneiss with foliation parallel leucosome along Route 22 south of Whitehall, NY in order to determine the timing of melting using both in-situ monazite and zircon U/Pb geochronology from the restite and leucosome layers of the same rock. Monazite was analyzed via in-situ EMPA on the Ultrachron microprobe at the University of Massachusetts. Zircon was analyzed via LA-ICP-MS (in-situ and mounted mineral separates) at the LaserChron Center. Monazite analyses from the restite yielded six compositionally distinct populations with dates of 1178 ...
Geologic Mapping And Geochronology Of The Heavens Gate 7.5-Minute Quadrangle: How Long Does It Take To Accrete An Island Arc To A Continent?, Samuel Gordon Deyoung
MSU Graduate Theses
The Blue Mountain province of western Idaho and eastern Oregon is composed of a mélange of geologic terranes that represent Permian and Triassic island arcs that collided with North America in the Mesozoic, resulting in westward growth of the continent. Separating these accreted rocks from North America are the mid- crustal metamorphic rocks of the Salmon River suture zone. Containing units and features associated with the accreted island arc terranes and suture zone is the Heavens Gate 7.5-minute quadrangle, located in Idaho county, Idaho. Within the quadrangle the Salmon River suture zone is divided into structural blocks by a ...
Fault Slip And Exhumation History Of The Willard Thrust Sheet, Sevier Fold‐Thrust Belt, Utah: Relations To Wedge Propagation, Hinterland Uplift, And Foreland Basin Sedimentation, 2019 Weber State University
Fault Slip And Exhumation History Of The Willard Thrust Sheet, Sevier Fold‐Thrust Belt, Utah: Relations To Wedge Propagation, Hinterland Uplift, And Foreland Basin Sedimentation, W. A. Yonkee, Bryan Eleogram, Michael L. Wells, Daniel F. Stockli, Shari Kelley, D. E. Barber
Geoscience Faculty Publications
Zircon (U‐Th)/He (ZHe) and zircon fission track thermochronometric data for 47 samples spanning the areally extensive Willard thrust sheet within the western part of the Sevier fold‐thrust belt record enhanced cooling and exhumation during major thrust slip spanning approximately 125–90 Ma. ZHe and zircon fission track age‐paleodepth patterns along structural transects and age‐distance relations along stratigraphic‐parallel traverses, combined with thermo‐kinematic modeling, constrain the fault slip history, with estimated slip rates of ~1 km/Myr from 125 to 105 Ma, increasing to ~3 km/Myr from 105 to 92 Ma, and then decreasing ...