Microtextural Constraints On The Interplay Between Fluidrock Reactions And Deformation, 2017 Utah State University
Microtextural Constraints On The Interplay Between Fluidrock Reactions And Deformation, Alexis K. Ault, Jane Selverstone
Schists from two mylonitic localities in the footwall of a low-angle normal fault in the eastern Alps record different degrees of embrittlement during exhumation, depending on the extent to which fluid–rock reactions proceeded. At one site, graphitic schists preserve textural evidence for two metamorphic reactions that modified XCO2XCO2 and/or fluid volume: (1) reaction between graphite and aqueous fluid that increased XCO2XCO2 without changing the molar amount of fluid, and (2) replacement of titanite by rutile, calcite, and quartz. The latter reaction involved net consumption of increasingly CO2-rich fluid. Areas where the first reaction proceeded are associated with abundant ...
Record Of Paleofluid Circulation In Faults Revealed By Hematite (U-Th)/He And Apatite Fission-Track Dating: An Example From Gower Peninsula Fault Fissures, Wales, Alexis K. Ault, Max Frenzel, Peter W. Reiners, Nigel H. Woodcock, Stuart N. Thomson
Fault rock low-temperature thermochronometry can inform the timing, temperature, and significance of hydrothermal fluid circulation in fault systems. We demonstrate this with combined hematite (U-Th)/He (He) dating, and sandstone apatite fission-track (AFT) and apatite and zircon (U-Th)/He (He) thermochronometry from fault-related fissures on the Gower Peninsula, Wales. Hematite He dates from 141 ± 5.1 Ma to 120 ± 5.0 Ma overlap with a 131 ± 20 Ma sandstone infill AFT date. Individual zircon He dates are 402–260 Ma, reflecting source material erosion, and imply a maximum Late Permian infill depositional age. Burial history reconstruction reveals modern exposures were ...
Phanerozoic Surface History Of The Slave Craton, 2017 Utah State University
Phanerozoic Surface History Of The Slave Craton, Alexis K. Ault, Rebecca M. Flowers, Samuel A. Bowring
New apatite (U-Th)/He (AHe) thermochronometry data and key geologic constraints from Slave craton kimberlites are used to develop a model for the Phanerozoic burial, unroofing, and hypsometric history of the northwestern Canadian shield. AHe dates range from 210 ± 13 to 382 ± 79 Ma, are older in the eastern Slave craton and decrease westward, and resolve the spatial extent, thickness, and history of now-denuded sedimentary units. Results indicate Paleozoic heating to temperatures ≥85–90°C, suggesting regional burial beneath ≥2.8 km of strata while the region was at sea level, followed by the westward migration of unroofing across the ...
Foreland-Directed Propagation Of High-Grade Tectonism In The Deep Roots Of A Paleoproterozoic Collisional Orogen, Sw Montana, Usa, Cailey B. Condit, Kevin H. Mahan, Alexis K. Ault, Rebecca M. Flowers
The study of deeply exhumed ancient collisional belts offers important constraints on geologic processes and properties complementary to inaccessible portions of the crustal column in active orogens. The ca. 1.8−1.7 Ga Big Sky orogeny in southwest Montana is a major convergent belt associated with the Proterozoic amalgamation of Laurentia. New structural, petrologic, and geochronologic data from the Northern Madison Range, crossing the NE-SW trend of the belt, record key information about the internal dynamics of the orogen. At least two phases of Big Sky−related deformation are preserved, both nearly coeval with peak metamorphic conditions of ∼0 ...
Hot Faults: Iridescent Slip Surfaces With Metallic Luster Document High-Temperature Ancient Seismicity In The Wasatch Fault Zone, Ut, Usa, James P. Evans, Mitchell R. Prante, Susanne U. Janecke, Alexis K. Ault, Dennis L. Newell
We document new geological indicators of ancient seismicity in the form of highly reflective, iridescent, hematite-coated fault surfaces. Small faults that cut the Paleoproterozoic Farmington Canyon Complex in the footwall damage zone of the Brigham City segment of the Wasatch fault (Utah, USA) are smooth to striated surfaces, tens of square centimeters to 30 m2 in area. The dull-rusty to high-metallic luster and moderate- to high-gloss surfaces exhibit multicolored elliptical iridescent patches ∼0.5–3 cm across. Preexisting hematite crystals were deformed during slip on 1–200-mm-thick slip surfaces. Textural observations, X-ray diffraction, X-ray photoelectron spectroscopy, electron backscattered diffraction analysis ...
Gravitational Study Of The Hastings Salt Dome And Associated Faults In Brazoria And Galveston Counties,Texas, 2017 Stephen F. Austin State University
Gravitational Study Of The Hastings Salt Dome And Associated Faults In Brazoria And Galveston Counties,Texas, Francis C. Okocha
Electronic Theses and Dissertations
Salt domes are important geological structures because they are potential major hydrocarbon traps and have a profound effect on overlying strata in the subsurface. Over five hundred salt domes have been located on the United States Gulf Coast region, including the Hastings Salt Dome. Hastings Oil Field is located about 40.2 km (25 miles) southeast of Houston, Texas. The Hasting oil field was discovered in 1934 and it was considered the largest oil reserve on the Gulf Coast. Its peak production of 75,000 BOPD (barrels of oil per day) was recorded in 1977 and it had a cumulative ...
Structural And Stratigraphic Reconstruction Of The Whiting Dome Salt Structure In Viosca Knoll-Mississippi Canyon, Gom, Using 3d Seismic Data, 2017 Stephen F Austin State University
Structural And Stratigraphic Reconstruction Of The Whiting Dome Salt Structure In Viosca Knoll-Mississippi Canyon, Gom, Using 3d Seismic Data, Matthew R. Worrell
Electronic Theses and Dissertations
Understanding the complexities of salt tectonics is one of the most important factors regarding seismic interpretation of stratigraphy, structure, and geomorphology in the Gulf of Mexico. Evaluating the processes affecting recent mobilization of salt in the shallow, well-imaged section can help provide analogues for older, similar occurrences in the deeper section, thereby providing structural models for the autochthonous salt and its effect on stratigraphy and even potential timing and migration issues of hydrocarbons.
Progradation of delta front and shelf to slope transitional sediments has expulsed and emplaced an allochthonous salt structure (Whiting Dome) in the Viosca Knoll and Mississippi Canyon ...
Spatio-Temporal History Of Fluid-Rock Interaction In The Hurricane Fault Zone, 2017 Utah State University
Spatio-Temporal History Of Fluid-Rock Interaction In The Hurricane Fault Zone, Jace Koger
All Graduate Theses and Dissertations
The Hurricane Fault is a 250-km long, west dipping, Basin and Range-bounding normal fault in SW Utah and NW Arizona that initiated in the mid-Miocene to Pliocene. It has been primarily active in the Quaternary, with slip rates of 0.2 – 0.6 mm/yr. There are multiple hot springs along its 250-km length and multiple late Tertiary-Quaternary basaltic centers broadly parallel the fault. Possible sources of hot spring fluids include deeply-circulated meteoric water that experienced water-rock exchange at high temperatures (>100 °C) and deep-seated crustal fluids. Aside from the source of modern hot spring fluids and heat, questions about ...
Heavy Metal Concentrations And Environmental Quality In Three Wisconsin Lakes, 2017 Whitman College
Heavy Metal Concentrations And Environmental Quality In Three Wisconsin Lakes, Alex Khawaja Waheed
The environmental history of lake ecosystems in the United States is broadly defined by a slow increase in contamination triggered by the Industrial Revolution and urbanization beginning around 1850, a sharper increase around 1950, and a general decrease following environmental legislation in the 1970s. This study examined sediment cores taken from three Wisconsin lakes spanning a range of human influence: Sparkling Lake (relatively pristine), Shadow Lake (remediated), and Lake Monona (impacted). Sediment cores were analyzed for heavy metal concentrations using X-ray Fluorescence (XRF) as well as for correlations with organic and calcareous content using loss on ignition (LOI). Sparkling Lake ...
Cyclothem Characterization For The Eastern Edge Of The Cherokee Basin, 2017 Fort Hays State University
Cyclothem Characterization For The Eastern Edge Of The Cherokee Basin, Luke Rijfkogel
John Heinrichs Scholarly and Creative Activities Day (SACAD)
The purpose of this project is to interpret lithologic units using geophysical data obtained from 8 wells in the Cherokee Basin. Results show Gamma Ray (GR) values range from less than 20 to 300 degree API, Photo-electric (PE), values range from 1.5 to 5.5 b/e, and Bulk Density (RHOB) values range from 1.5 to 2.8 g/cc. 5 major facies were identified and recognized 27 lithology units, including 10 coal beds. The other facies include Sandstone, Shale and Limestone. The abundance of interbedded coal layers indicate cyclical deposition, alternating between high and low energy deposits.
Nutrient Variations Of Six Surface Water Bodies In Mchenry County, Il, 2017 Augustana College, Rock Island Illinois
Nutrient Variations Of Six Surface Water Bodies In Mchenry County, Il, Jacob Piske
Celebration of Learning
This research analyzes water quality from several ponds in McHenry County, Illinois, with a goal of developing a understanding of pollution sources and temporal variations in concentrations of nitrate, potassium, phosphorus, chlorine, and sodium. Over the past 25 years, the population of McHenry County has grown rapidly, with residential developments expanding into former farmlands. Yet, the county remains heavily agricultural, with roughly 60% of the surface area used for agricultural purposes. Concentrations of NO3-, P+, K+, Cl-, and Na+ were analyzed from six sites: two in subdivisions, two in farmland, and two near major highways. Data were collected once a ...
Dendrochronological Analysis Of Historical Structures In Southwestern Ohio Dewitt House Oxford, Ohio., 2017 The College of Wooster
Dendrochronological Analysis Of Historical Structures In Southwestern Ohio Dewitt House Oxford, Ohio.
Dating historical structures in Oxford Ohio using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Fetters, Caitlin; Krivicich, Mike; Lehmann, Sophie; Wiles, Greg
The Groundwater Atlas Of Richardson County, Nebraska, 2017 University of Nebraska - Lincoln
The Groundwater Atlas Of Richardson County, Nebraska, Dana P. Divine, Leslie M. Howard
Conservation and Survey Division
The purpose of this groundwater atlas is to synthesize a wealth of hydrogeologic data for Richardson County that has not been published in readily accessible formats previously. Many of the maps presented herein are based on data from registered well logs and test hole logs that are publicly available on-line, which become more valuable when compiled, analyzed, and discussed as a whole. The focus of the maps presented in this report is the accessibility of groundwater for pumping.
Terroir Studies In Washington And Wisconsin American Viticultural Areas, 2017 University of Wisconsin-Milwaukee
Terroir Studies In Washington And Wisconsin American Viticultural Areas, Snejana Karakis
Theses and Dissertations
The concept of terroir has been evaluated since the 12th century, when Cistercian monks from Burgundy realized that the physical environment in which grapes are grown has a major influence on the character and quality of the resulting wine. These environmental conditions affecting grape and wine quality are known as terroir in viticulture and have become increasingly important in the grape growing and wine industry. In this dissertation, three studies investigating the terroir of vineyards located in Washington and Wisconsin American Viticultural Areas (AVAs), which are defined by the Alcohol and Tobacco Tax and Trade Bureau (TTB) as delimited grape-growing ...
A Floral Assemblage Of The Upper Cretaceous El Gallo Formation, El Rosario, Baja California, Mexico, 2017 Department of Geosciences, University of Rhode Island
A Floral Assemblage Of The Upper Cretaceous El Gallo Formation, El Rosario, Baja California, Mexico, Reilly F. Hayes, Marisol Montellano-Ballesteros, Gerardo Álvarez-Reyes, René Hernandez-Rivera, David E. Fastovsky
Senior Honors Projects
Over the past eight months, I have collaborated with paleontologists from the Universidad Nactional Autónoma de México to formally describe plant fossils they uncovered in Baja California between their 2013 and 2016 field seasons. We report the first floral assemblage of the dinosaur-aged El Gallo Formation, Baja California, Mexico, a small (82-specimen) collection of plant fossils from fossil soils contained within the 75.84 +/- 0.05 to 74.55 +/- 0.09 million-year-old El Disecado Member of the unit. A compound fruit belonging to the genus Operculifructus, previously reported from the 3.40 to 1.08 million year younger Cerro del ...
Basement And Cover Structural Analysis Along The Eagle River Gorge, Sawatch Range, Colorado, 2017 Stephen F Austin State University
Basement And Cover Structural Analysis Along The Eagle River Gorge, Sawatch Range, Colorado, Kaitlin Lee Askelson
Electronic Theses and Dissertations
The Sawatch Range within the Rocky Mountains of central Colorado exposes Paleoproterozoic basement and overlying Paleozoic sedimentary rocks with a complex history of ductile and brittle deformation.
The goal of this study is to conduct analyses of brittle structures that occur in the basement and cover units to determine geometric relationships between the structures, provide a detailed description of structures and refine a geologic history for structures along the basement-cover contact in the northeastern Sawatch Range along the Eagle River canyon and U.S. Highway 24 from Red Cliff to Gilman, Colorado. Paleoproterozoic basement rocks include the Cross Creek granite ...
Characterization Of Stress Changes In Subduction Zones From Space- And Ground-Based Geodetic Observations, Bryan James Stressler
Theses and Dissertations
Temporally and spatially clustered earthquake sequences along plate boundary zones indicate that patterns of seismicity may be influenced by earthquake-induced stress changes. Many studies invoke Coulomb stress change (CSC) as one possible geo-mechanical mechanism to explain stress interactions between earthquakes, their aftershocks, or large subsequent earthquakes; however, few address the statistical robustness of CSC triggering beyond spatial correlations. To address this, I evaluate the accuracy of CSC predictions in subduction zones where Earth’s largest earthquakes occur and generate voluminous and diverse aftershock sequences. A series of synthetic tests are implemented to investigate the accuracy of inferred stress changes predicted ...
Diverse Monogenetic Volcanism Across The Main Arc Of The Central Andes, Northern Chile., 2017 University of Iowa
Diverse Monogenetic Volcanism Across The Main Arc Of The Central Andes, Northern Chile., Brennan Martin Edelman De Roo Van Alderwerelt
Theses and Dissertations
Instances of fault-controlled monogenetic volcanism across the subduction arc of the Central Andes at ~ 23°S illuminate the nature of different parental melts being delivered to the crust. Evidence of magmatic history is preserved in bulk rock geochemistry, the content of melt inclusions, and mineral compositions. Volcanism in this region is dominated by felsic and intermediates lavas as the thickened crust (55 – 65 km) and vast volumes (> 500,000 km3) of mid-crustal magma beneath the Altiplano-Puna high plateau region prevent mafic magmas from reaching the surface (Davidson & De Silva, 1991; Beck et al., 1996; Perkins et al., 2016). However, small volumes of relatively ...
Global Deforestation Prediction: Summer Internship At Clark Labs, 2017 Clark University
Global Deforestation Prediction: Summer Internship At Clark Labs, Tianze Li, Yahsee Joshi
International Development, Community and Environment (IDCE)
This paper is a description of our internship with Clark Labs in the summer of 2016. We worked as research assistants in the Deforestation Risk Prediction project for Ecosystem Services team. This goal of the project was to predict deforestation at global, continental and national level. Our responsibilities were to choose the variables that may influence the deforestation and to use Land Change Modeler in TerrSet to test the variables and create the deforestation prediction maps. We highly recommend this internship with Clark Labs to other GISDE students who are interested in land change analysis.
Comparison Of Flow Dynamics And Bifurcation Angles In Tributary And Distributary Channel Networks, 2017 University of Arkansas, Fayetteville
Comparison Of Flow Dynamics And Bifurcation Angles In Tributary And Distributary Channel Networks, Thomas Coffey
Theses and Dissertations
The dynamics of channel mouth bifurcations on river deltas can be understood using theory developed in tributary channel networks. Bifurcations in groundwater-fed tributary networks have been shown to evolve dependent on diffusive ground water flow patterns
directly adjacent to the channel network, producing a critical angle of 72°. We test the hypothesis that bifurcation angles in distributary channel networks are likewise dictated by a diffusive external flow field, in this case the shallow surface water surrounding the subaqueous portion of distributary channels in a deltaic setting. We measured 25 unique distributary bifurcations in an experimental delta and 197 bifurcations in ...