PhD, University of Cincinnati, 2023, Arts and Sciences: Geology

Integration of event-stratigraphy, biostratigraphy, chemostratigraphy, and allostratigraphic methodology yields high-resolution correlations and helps to elucidate processes in the ancient past. This study presents an integrated stratigraphic approach applied to a Late Ordovician (Sandbian - Katian) mixed carbonate platform, cratonic basin system in Kentucky and Ohio. Identification of four widespread carbon isotope excursions (Logana, Macedonia, Brannon, and Bromley) enhanced regional chronostratigraphic correlations. Further, event beds (faunal epiboles, ash beds, deformed horizons) differentiated non-unique signatures in the stratigraphy and corroborated correlations. Numerous stratigraphic sections of the Lexington Platform (outcrops and core throughout) were studied to improve the existing stratigraphic framework and revisions to the regional correlation and nomenclature are documented. Key basin and basin margin reference sections (Cadiz Core, Middletown Core and others) were analyzed for stratigraphic patterns and whole rock carbon isotopes (d13Ccarb), percent total organic carbon, and elemental abundance (pXRF) in addition to detailed (bed scale) lithostratigraphic study. The Point Pleasant Basin (east-central Ohio) underwent differential subsidence relative to the Lexington Platform (central Kentucky) in three distinctive phases. Despite the progressive differentiation of the two depositional environments, integrative stratigraphy (especially faunal epiboles and d13Ccarb excursions) permits direct comparison. Widespread soft-sediment deformation (seismites) and increased occurrence of ash beds (k-bentonites) are coincident with the onset of increased differentiation of the Lexington Platform from the Point Pleasant Basin supporting a tectonic driver. However, small-scale sequences are recognizable across significant facies changes, supporting an overall eustatic origin of cyclicity. Carbon isotopic trends across much of the Laurentian Craton, plat (open full item for complete abstract)

Committee: Carlton Brett Ph.D. (Committee Chair); Thomas Algeo Ph.D. (Committee Member); Daniel Sturmer (Committee Member); Patrick McLaughlin Ph.D. (Committee Member); Peter Holterhoff Ph.D. (Committee Member) Subjects: Geology

Doctor of Philosophy, Case Western Reserve University, 2017, Geological Sciences

The Ordovician Utica Shale is an extensive and important part of the Appalachian Basin subsurface, providing a source for Paleozoic hydrocarbon reservoirs, acting as an unconventional hydrocarbon reservoir, and of interest as an impermeable cap rock for carbon dioxide sequestration in Cambrian formations. The Utica Shale is mostly in the subsurface, with little outcrops in areas of interest, and those that do exist are typically within the Appalachian Mountains (New York). To observe changes in subsurface formations, a combination of core and well logging can provide an extensive look into the subsurface. Here we present a non-destructive core-logging technique to quickly assess mineralogy variations on the Ordovician Trenton/Lexington Limestone, Point Pleasant Formation, and Utica Shale in Ohio. These core logging results, along with several previously measured core mineralogy, were then correlated to well logging electrofacies to extrapolate mineralogy and rock type from a few location to across the state. These were then mapped to identify controls on deposition during the Upper Ordovician in Ohio. Although typically assumed that the only controls on deposition during this time period are the primarily the Appalachian, and to a lesser extent Michigan, Basins, Precambrian basement structures, such as the Waverly Arch, Utica Mountain Fault, and Harlem Fault, have influence on deposition and sediment mixing also. Finally, the Sebree Trough, which has previously been reported to stop in southwest Ohio, appears to have allowed for dark, calcite-poor shales to continue deposition towards northeast Ohio, as a possible trough-like feature extending off of the Sebree Trough. The Trenton/Lexington Limestones, Point Pleasant Formation, and Utica Shale are not homogenous rock types, deposited across the state, but rather variable in both facies and thickness.

Committee: Beverly Saylor (Committee Chair); Gerald Matisoff (Committee Member); Steven Hauck (Committee Member); Xiong Yu (Committee Member); Jonathan Cowen (Committee Member) Subjects: Geology

Master of Science, The Ohio State University, 2016, Earth Sciences

While life is known to exist in the subsurface environment, specific limitations to microbial populations inhabiting deep subsurface habitats are assumed and include organic substrate and terminal electron acceptor availability, temperature and space to live. Microbial populations have been found in environments where they are least expected, notably 3 km deep in granite as well as in the boreholes and near-borehole environment of oil and gas wells where they often cause problems for oil and gas operators. While an anthropogenic source is assumed for microbes in and near the borehole of oil and gas wells in the Utica-Point Pleasant system due to the high temperatures the rock has undergone, the question remains whether microbial populations could have survived in less mature rock to the West of contemporary oil and gas operations. As a component of an NSF funded study “Microbial Biodiversity and Functionality of Deep Shale and it's Interfaces” this research attempts to answer whether microbes could have survived to the present day in pores as well as questions relating to biological limitations and whether these are present in the Utica-Point Pleasant. Looking at sulfur, organic carbon and potential micro-lithologies within the Utica-Point Pleasant organic-rich mudstone may yield a better understanding of how the diagenesis of a marine mud affects anaerobic microbial populations established in these muds. Utilizing a variety of petrophysical, geochemical and high resolution imaging techniques this research has identified micro-lithologies within the Utica-Point Pleasant system that likely provided safe harbor for anaerobic microbes until the habitat was either sterilized due to temperature or in-filled with minerals, sealing off these habitats. Further, these micro-lithologies may respond to hydraulic fracturing chemicals and processes and become inhabitable for anthropogenically introduced microbial populations.

Committee: David Cole PhD (Advisor); Matthew Saltzman PhD (Committee Member); Michael Wilkins PhD (Committee Member) Subjects: Chemistry; Earth; Geology; Microbiology

Master of Science (MS), Ohio University, 2016, Geological Sciences (Arts and Sciences)

A combination of x-ray diffraction analyses of core data and spectral gamma ray logs were used to interpret the largely shale succession of the Late Ordovician between the top of the Trenton Limestone and the Queenston Shale in the subsurface of east-central Ohio. The four county study area is within the back-bulge region of the foreland basin associated with the Taconic Orogeny. The XRD data from the basal portion of the section reveal an increase upward in chlorite and quartz along with a decrease in carbonate, which is consistent with an increase in detrital rather than authigenic clays. Detrital chlorite is a common clay mineral in sediments shed from mountain belts and the appearance of the clay allows constraints to be placed on the transition from under to overfilled foreland basin. Correlation of six 4th-order sequences from 300 wells allowed construction of isopach maps throughout the 450 m interval. The isopach maps show that subsidence across the area was consistent and augmented by some combination of compaction over pre-existing structural and depositional features

Committee: Greg Nadon (Advisor) Subjects: Geological

Master of Science (MS), Wright State University, 2014, Earth and Environmental Sciences

Using well logs and AVO gradient analysis, I identify and characterize a package of reflectors associated with the Utica Shale from vibroseis data collected by Wright State University at the Gabor Gas Storage field near Canton, Ohio. I also correlate TOC measurements from wells to densities and velocities at the same depths. On the seismic data, I interpret prominent reflections from the top and bottom of the Utica Shale and an intra-Utica reflector of varying frequency content associated with a velocity/density low in well log data. I investigate the possibility that the lateral variation in frequency content and change in wavelet character of these reflections is influenced by velocity gradients, termed Wolf Ramps. A Matlab software script was written in order to approximate this behavior using synthetic wavelets, and the resulting model matched well with the seismic data. Additionally, I note a possible reverse fault within the Utica that could create fracture porosity and a migration pathway. To model the AVO response, an AVA volume was created from prestack data and reflection coefficients up to 30 degrees of incidence were calculated using the two-term Aki-Richards approximation. Large negative normal incidence reflection coefficients attenuated at higher angles of incidence (Class IV anomalies) were observed at the top of Utica reflector, a response consistent with a change from silica-rich nonsource shale to black source shale. Large positive normal incidence reflection coefficients decreasing at higher angles of incidence (Class I anomalies) were noted at the bottom of Utica reflector, consistent with a shift from low impedance source shale to higher impedance calcareous shale. To perform forward modeling, I used geophysical well logs and NS-EW vibroseis line data. Using Hampson Russell commercial software, acoustic impedance and reflectivity were computed from sonic and density logs. An average wavelet at the Utica two-way travel time was extracte (open full item for complete abstract)

Committee: Doyle Watts Ph.D. (Advisor); Ernest Hauser Ph.D. (Committee Member); David Dominic Ph.D. (Committee Member) Subjects: Geology; Geophysics

MS, University of Cincinnati, 2002, Arts and Sciences : Geology

Several intervals of soft sediment deformation are present within the Upper Ordovician strata of Kentucky and Ohio. The following two chapters describe features of these deformed beds. The first chapter describes, in detail, deformed beds present within predominantly late Shermanian age strata. This first chapter not only describes the sedimentary structures associated with these deformed intervals, but also discusses their aerial and stratigraphic distribution, required sedimentary architecture, and triggering mechanisms that may have generated the deformation. Hypotheses generated in the first chapter proposes that there exist two classes of deformational features each related to lithology and sedimentary architecture, and that the stratigraphic distribution of these two classes is predictable within a depositional sequence. The final chapter of this study provides a test of the generality of these hypotheses using the record from eight depositional sequences ranging from the lower Lexington Limestone (Chatfieldian) to Fairview Formation (Maysvillian). The distribution of deformed beds during this time interval (~12 million years) yields insight into the tectonic evolution of eastern Laurentia during the Taconic Orogeny.

Committee: Dr. Carlton Brett (Advisor) Subjects: Geology