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 ...
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 ...
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 (An44-100) plagioclase and magmatic amphibole. These ophiolites formed predominantly at convergent plate margins, with some ...
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 ...
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, 2020 Central Washington University
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 ...
Documenting The Earthquake History Of The Thousand Springs Fault In Summer Lake Basin, Oregon, Usa, 2020 Central Washington University
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 TSF ...
Detrital Zircon Petrochronology For Sedimentary Provenance Analysis: Source To Sink Of The Mississippi/Missouri River Drainage Basin, Sage Denali Muttel
MSU Graduate Theses
Detrital petrochronology can provide a detailed look into sedimentary provenance through integrated mineral radioisotopic ages with corresponding mineral chemistry. By combining U-Pb ages and Th/U values of detrital zircon from 13 samples collected from Quaternary sand deposits in the Upper Missouri, Yellowstone, Bighorn, Platte, Kansas, Arkansas, Mississippi, Red and Brazos Rivers, an interpretation of detailed signatures that record evidence of the evolution of the Mississippi/Missouri River drainage and the tectonic events that shaped it were observed. Low Th/U values in zircon correlate temporally to convergent magmatism, whereas, higher and more variable Th/U zircon are coeval with ...
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 ...