Master of Science, Miami University, 2023, Geology and Environmental Earth Science

Fluvial terraces are vital to reconstructing past depositional dynamics within a watershed as well as determining flood and erosion risk. In the midwestern US, detailed mapping of terrace age is necessary to determine if deposition occurred during multiple distinct periods. In this study, changes to soil geochemistry over time were quantified from nine radiocarbon-dated soils spanning ~17,000 years and this relationship was used to infer soil age across a broad fluvial terrace. Regression models quantifying Fe/Ca, Zr/Ca, and Ti/Ca changes at multiple soil depths were created. Fe/Ca models returned R2 values between 0.69 and 0.97 with the lowest uncertainties compared to Zr/Ca and Ti/Ca models. Samples collected at 20-30 cm depth resulted in the highest correlation coefficient compared to samples collected at 0-10 and 60-70 cm. The mean Fe/Ca value of parent material was 0.33 with standard deviation 0.12. The models were subsequently used to infer soil age from Fe/Ca values of 388 locations on the floodplain and overbank deposits were delineated based on inferred soil age. In general, deposit age increases with increasing distance from the modern channel. Results support use of this field-based technique to map fluvial terraces at a high resolution.

Committee: Jason Rech Dr. (Advisor); Maija Sipola Dr. (Committee Member); Claire McLeod Dr. (Committee Member) Subjects: Earth; Geology; Geomorphology; Soil Sciences

Master of Science (MS), Wright State University, 2021, Earth and Environmental Sciences

The Theis Environmental Monitoring and Modeling Site is a field research facility, located on the Great Miami River in southwest Ohio, dedicated to the study of hyporheic zone processes. The site is underlain by an aquifer on the order of 21 meters thick, comprised of fluvial deposits. The permeability of the aquifer sediments was quantified both from one large scale hydraulic test (~100 m radial distance) and from grain-size analysis of 119 small-scale core samples (~20 cm length each). The permeability determined from the large-scale hydraulic test is 98.9 Darcies. The test also gave a value for specific yield of 0.25. The geometric mean of the small-scale measurements is 88.3 Darcies, close to the value of the large-scale measurement, and within the central tendency of the distribution of previously published measurements. The aquifer contains an inferred hierarchy of sedimentary architecture, with compound bar deposits comprising unit bar deposits, and unit bar deposits comprising stratasets with different grain-size facies, including sand, gravelly sand, sandy gravel, and gravel. The stratasets are less than a meter thick and less than 10 meters in length. Intervals of sand facies make up 18.5% of the aquifer, have a mean thickness of 0.75 m (standard deviation (σ) of 0.37 m), a mean permeability of 86.8 Darcies (σ of 47.8 Darcies), and a mean porosity of 36% (σ of 4%). Intervals of gravelly sand facies make up 25.2% of the aquifer, have a mean thickness of 0.96 m (σ of 0.46 m), and a mean permeability of 73 Darcies (σ of 49.9 Darcies), and a mean porosity of 28% (σ of 3%). Intervals of sandy gravel facies make up 36.1% of the aquifer, have a mean thickness of 1.00 m (σ of 0.79 m), and a mean permeability of 84.9 Darcies (σ of 49.7 Darcies), and a mean porosity of 25% (σ of 3%). Intervals of gravel facies make up 20.2% of the aquifer, have a mean thickness of 1.10 m (σ of 0.74 m), and a mean permeability of 670 Darcies (σ of 1170 Darcies), and a me (open full item for complete abstract)

Committee: Robert W. Ritzi Jr., Ph.D. (Committee Chair); David A. Schmidt Ph.D. (Committee Member); David F. Dominic Ph.D. (Committee Member) Subjects: Geological; Geology; Hydrologic Sciences; Hydrology

Master of Science, The Ohio State University, 2022, Environment and Natural Resources

Unmanned aerial vehicles (UAVs) have an increasingly relevant role in the field of hydrology and water resources management. Their affordability and ease of use in comparison to traditional field-based methods have made research on their applications increase rapidly in the past decade. One application of UAVs to the hydrology of river systems is the estimation of particle sizes within a channel. This project investigated the ability of UAV imagery and Structure-from-Motion (SfM) photogrammetry to estimate grain-size distributions within a reach along the Olentangy River. To do this, we selected a study reach within the Highbanks Metro Park that was approximately 250 m in length and 50 m in width. We flew a DJI Mavic 2 Pro quadcopter UAV and collected imagery of subaerially exposed grains throughout gravels bars within this study reach. These images were processed using a SfM workflow that yielded point clouds and orthomosaics from which we extracted multiple topography-based and image-based metrics to be used as proxies for grain sizes. We then calibrated statistical regression models to predict the D50 and D84 grain size percentiles from these grain size proxies. While previous literature has suggested that topographic roughness metrics outperform image textural metrics for statistical grain size estimation, our study showed that the statistical models that were calibrated based on image textural properties performed better than those that were calibrated based on point cloud roughness properties. This contradiction may reflect the unique nature of our study site where the grains were dominated by smaller particles in comparison to other studies. The smaller grain sizes in our study area would have likely produced less significant topographic signatures in comparison to larger grains, which makes topographic roughness difficult to accurately measure and apply to statistical grain size estimation techniques. The results of this study suggest that topography-based g (open full item for complete abstract)

Committee: Steve Lyon (Advisor); Sami Khanal (Committee Member); Kaiguang Zhao (Committee Member) Subjects: Environmental Science; Geology; Geomorphology; Hydrologic Sciences; Hydrology; Water Resource Management

Doctor of Philosophy, The Ohio State University, 2019, Environment and Natural Resources

Urbanization of watersheds leads to myriad changes to streams, including modified sediment and streamflow regimes that can result in altered fluvial geomorphic processes and channel structure. Hydrogeomorphic features have been linked to community composition of aquatic biota, as well as to stream ecosystem functioning. Biotic communities in urban stream ecosystems can be markedly different than their counterparts in more natural streams, often exhibiting reduced abundance, diversity, and shifts in assemblage composition, though the specific mechanisms through which urban land use and subsequent hydrogeomorphic modification effects these changes remain unresolved. Hydrogeomorphic modifications may impact both instream habitat as well as connectivity to the surrounding landscape, influencing both biotic assemblage composition as well as ecological connectivity between streams and their adjacent riparian zones. In 23 small urban stream reaches in the Columbus Metropolitan Area (CMA), Ohio, USA, I investigated potential linkages between urban-induced hydrogeomorphic characteristics and: (1) fish assemblage compositional changes over time (3-5 years); (2) fish assemblage trophic dynamics; (3) aquatic-to-terrestrial nutritional subsidies to a common riparian consumer (spiders of the family Tetragnathidae); and (4) downstream drift of larval macroinvertebrates in the water column. Hydrogeomorphic features related to instream habitat, the hydraulic environment (e.g., slope, shear stress, D50 [median bed sediment particle size]) and stream-floodplain connectivity (e.g., entrenchment ratio, sinuosity, incision ratio) emerged as common influences on fish assemblage composition and trophic dynamics, aquatic-terrestrial connectivity, and invertebrate drift. At a subset of 12 study reaches, several hydrogeomorphic variables showed significant changes over 3-5 years, with many decreasing (e.g., discharge [by 39%], slope [by 0.1%], and shear stress [by 29%, which decreased in co (open full item for complete abstract)

Committee: Mažeika Sullivan PhD (Advisor); Lauren Pintor PhD (Committee Member); Charles Goebel PhD (Committee Member) Subjects: Aquatic Sciences; Ecology; Environmental Science

Master of Science (MS), Bowling Green State University, 2018, Geology

The Cambrian Eau Claire Formation in western Ohio was examined using depositional systems analysis. This study investigated whether the transgressive barrier depositional model of Banjade (2011) for the adjacent Conasauga-Kerbel Formations also applies to the Eau Claire Formation. This research has determined that Cambrian estuarine/lagoonal deposits are present in western Ohio. This research found a systematic upward change in the Eau Claire Formation from siliciclastic deposits to carbonate deposits. As such, the Eau Claire Formation represents a transition between siliciclastic deposition of the underlying Mt. Simon Sandstone to the carbonate deposition of the overlying Knox Dolomite. This study also found that the contact between the Mt. Simon Sandstone and Eau Claire Formation to be a ravinement surface, and a probable transgressive surface of erosion, in the key study well. Two cores of the Eau Claire Formation were examined: one core contains 184-m of section from well DGS-2627 (Warren County, OH) and the other contains 134-m of section from well BP- 4 (Core 3502) (Allen County, OH). Microfacies analysis was conducted from each core as well as paleontology (cryptospore) analysis. Gamma-ray logs were obtained in LAS format from the Ohio Geological Survey for Warren (DGS-2627), Allen (BP-4), Miami (Walker Ella-1), Auglaize (Hoelscher D&B Comm-1), Defiance (Haver Pearl A-1), and Shelby (Borland-1) counties in Ohio. Once the data was constructed into log format, the BP-4 (Allen County) core data could be correlated with the log data, in other words, lithofacies observed in the core could be matched to the respective geophysical profile. Based on the relationships described above, a geophysical log model was constructed for BP-4. This log model is used to predict depositional facies from other wells that have only geophysical log data. The model was calibrated using both core and geophysical log data from core DGS 2627 in Warren County by predicting d (open full item for complete abstract)

Committee: James Evans Ph.D. (Advisor); John Farver Ph.D. (Committee Member); Jeffrey Snyder Ph.D. (Committee Member) Subjects: Geology

Master of Science (MS), Bowling Green State University, 2017, Geology

Urbanization impacts hydrologic systems, including changes in flood magnitude and frequency, sediment budgets, and channel morphology. As attempts are made to restore urban rivers, complications arise when trying to understand the extent of human-caused changes in channel substrates. This study looks at the sedimentary record in oxbow lakes as an archive of historical changes in channel substrates. The study area is a 3.5 km reach of Swan Creek containing three oxbow lakes. The two most significant events, related to land-use changes in the study area are: (1) land clearance for agriculture in the upper drainage basin starting around 1850 and continuing into today, and (2) urbanization of the lower watershed, specifically from 1945-1970 during a peak of new home construction. Historical aerial photographs and topographic maps were collected from the United States Geological Survey (USGS) and the Ohio Geographic Rectification and Information Program (OGRIP). The root mean square errors (RMSE) of these ranged from 0.19 to 0.77, an average RMSE of 0.47+/-0.20 m Using historical images and historical flood records It was determined that one of the oxbows formed during a channel avulsion before 1940. Trenches in this oxbow show coarse-grained sand and fine pebbles representing the post-urbanization channel (-0.8 phi +/- 2.5). The other two oxbows predate the imagery and contain a finer channel substrate (0.7 phi +/- 1.07). Furthermore, the sinuosity in the study area increased from 1.88 in 1935 to 1.98 in 2006. When available, anthropogenic materials such as food packaging labels found in trenches 16SC5 and 16SC2 were used to provide approximate ages for layers. In other cases, organics ii were dated using 14C dating. The samples yielded results of 1469+/-35 YBP (16SC5), 94+/-22YBP (16SC5), and 928+/-YBP(16SC8) . Channel substrate changes due to human activity have been studied in the Eastern U.S., but they have not been studied in detail in the Midwest. Eastern U. (open full item for complete abstract)

Committee: James Evans Dr. (Advisor); Sheila Roberts Dr. (Committee Member); Jeffrey Snyder Dr. (Committee Member) Subjects: Environmental Geology; Geomorphology

Master of Science, University of Akron, 2017, Geology-Environmental Geology

Population growth during the 20th century in Northeast Ohio has led to an overall increase in developed land cover and anthropogenic pollution such as fossil fuel combustion. Urban expansion and fossil fuel combustion result in an increase of polluted runoff into fluvial systems, which jeopardizes water quality, undermines infrastructure, and stresses local ecosystems that buffer floods. This study compares heavy metal pollution levels and land cover change during the 20th century in dammed impoundments within the rural Haskell Run watershed (Lake Butler), the rural Ritchie Run (Lake Litchfield), and the urban Mud Brook watershed (Old Mill Pond) in Northeast Ohio. Surficial sediment samples were collected from each impoundment to assess current pollution levels and sediment cores were collected for the past record of pollution. The two end-member watershed types have similar bedrock, glacial history, and climate, however, land cover differs greatly. Between 1985-2010, there was no land cover change in the rural Ritchie Run watershed, and in 2010, Ritchie Run had 3.4% developed land cover and 0.63% impervious cover. During the same period, the rural Haskell Run watershed increased by 1.37% in developed land cover, and in 2010, 12% of the Haskell Run watershed was developed land and 3.3% was impervious cover. Developed land cover, from 1985-2010, increased by 15.3% in the urban Mud Brook watershed, and in 2010, 74% was developed land cover and 23% was impervious cover. Old Mill Pond impoundment sediments were found to have higher heavy metal and ferrimagnetic concentrations, whereas, Lakes Butler and Litchfield sediments have comparatively lower heavy metal and ferrimagnetic concentrations. There is a moderate direct relationship between heavy metal and ferrimagnetic content. Therefore, magnetics can be used as an inexpensive and rapid screening tool for heavy metal pollution studies. The Old Mill Pond sediment core records an increase in heavy metal and ferrimagnetic (open full item for complete abstract)

Committee: John Peck (Advisor); John Senko (Committee Member); Linda Barrett (Committee Member) Subjects: Environmental Geology

Master of Science, University of Akron, 2016, Geology

The goal of this study was to determine the relative contributions of increased flood frequency and continued land development on geomorphic change and damage to infrastructure throughout the Yellow Creek, OH watershed. Comprised of five sub-watersheds, the Yellow Creek watershed is located in Northeast Ohio and is a tributary of the Cuyahoga River. In Northeast Ohio, a statistically significant change point in both heavy precipitation and stream flow occurred in July 2003. On the USGS Cuyahoga River Old Portage stream gage record, there were only 18 days of mean daily discharge above the top 1% flood category (76 m3s-1) during the 13 years prior to July 2003 compared to 79 days in the 13 years after July 2003. Land cover data reveals that impervious cover in the watershed has increased by 0.80% from 1985-1996, 0.32% from 1996-2001, 0.67% from 2001-2006, and 0.38% from 2006-2010. The five sub-watersheds have contrasting development histories and vary from 4.5% to 23.5% imperviousness. Water level loggers were installed to measure hydrograph variability between the five sub-watersheds. Water samples were also taken on 11/10/15, 2/3/16, and 2/24/16 in the five sub-watershed streams to find the effect development has on road salt concentration in the stream. Aerial photos for nine years between 1994 and 2015 were used to assess changes in stream geomorphology through time. Results show that geomorphic change has been greater after July 2003 compared to before July 2003. These post-2003 geomorphic changes include an increase in unvegetated mid-channel bars and point bars as well as amplified channel migration. Elsewhere, Yellow Creek shows straightening and widening in response to increased flooding events. The 2000 to 2005 and 2012 to 2015 photo intervals showed the largest geomorphic change throughout the Yellow Creek watershed, especially in areas with steep topography and stream slope. Although urbanization in the watershed results in increased runoff, since 2003 in (open full item for complete abstract)

Committee: John Peck (Advisor); Linda Barrett (Committee Member); John Senko (Committee Member) Subjects: Geomorphology; Hydrology

Master of Science in Environmental Science, Youngstown State University, 2016, Department of Physics, Astronomy, Geology and Environmental Sciences

Development of riparian forests typically reflects varying influences of flood disturbance and/or primary succession. The main objective of this study within the Lake Erie Gorges of New York and Pennsylvania was to understand the contributions of geomorphology, hydrology, and sedimentology to a disturbance vs. succession continuum within middle order riparian zones of Western New York State, USA. Forest composition has been quantitatively surveyed within eight selected river corridors in the region, chosen to be as free of human disturbance as possible, with stand ages estimated by increment coring. (Data from the extensively surveyed Zoar Valley Canyon of Cattaraugus Creek are also discussed throughout this thesis in terms of their contribution to the regional patterns assessed here.) Some river corridors were characterized by coarse cobble/boulder sediments, whereas others represented fine cohesive muds and silts. Total basal area and basal area (BA) for each species were catalogued on various sized quadrats on aggradational and forms. Also calculated were mean diameter at breast height (DBH) and its coefficient of variation (CV), species diversity (Shannon Weiner H'), and percentage of BA in shade tolerant species. Patterns in species composition and stand structure and their association with stand age were assessed by logarithmic regression and nonmetric multi-dimensional scaling ordination. Thirty-seven tree species were encountered, and stand ages ranged from 9 to 147 years (some Zoar Valley stands exceeded 250 years). Coarse sediment landforms exhibited high diversity and shade tolerance, both of which increased at greater stand age. In contrast, fine sediment landforms exhibited lower diversity, dominated by shade intolerant, flood responding pioneer species, with no increase in diversity at greater stand age. Riparian forests on coarse-sediment landforms, including Zoar Valley Canyon, reflected primary succession driven by establishment of gravel- (open full item for complete abstract)

Committee: Thomas Diggins PhD (Advisor); Colleen McLean PhD (Committee Member); Dawna Cerney PhD (Committee Member); Christopher Mattheus PhD (Committee Member) Subjects: Biology; Botany; Ecology; Environmental Science; Forestry

Master of Science, University of Akron, 2015, Geology

In recent years, the removal of dams from U.S. rivers has become a more frequent method of river restoration. The August 2013 removal of the 4.1-m-tall LeFever Dam in Cuyahoga Falls, Ohio was the fourth dam removed on the middle Cuyahoga River in an attempt to improve water quality. The LeFever Dam removal has also provided an excellent opportunity to study the effects of low head dam removal on the fluvial environment. Previous studies on the middle Cuyahoga River have provided a comprehensive characterization of the former LeFever dam pool and the pre-LeFever removal conditions. Previous studies have also quantified the effect of the 2005 Munroe Falls Dam removal which served as predictive tool for the LeFever Dam removal located ~ 5.5 km downstream. This study has incorporated new findings from 2011 through 2015 to quantify the rate and magnitude of the geomorphic, sedimentologic and hydraulic changes induced by the LeFever Dam removal. These new findings furthered the understanding of the long-term channel adjustments induced by the Munroe Falls Dam removal as well. The six stage channel evolution model of Doyle et al. (2003) was used as the framework for describing the first-order changes brought about by the LeFever Dam removal and the long-term changes caused by the Munroe Falls removal. However, this study has found site-specific dissimilarities in the channel evolution model that have greatly influenced channel morphology. In addition, the former LeFever Dam pool has progressed through channel evolution at a faster rate than the former Munroe Falls Dam pool because the Cuyahoga River has more slope energy near the former LeFever Dam. The presence of large woody debris and the occurrence of high discharge events have significantly increased the rate of channel erosion in the study reach. Channel coarsening has resulted from both dam removals as well as pronounced degradation of the former LeFever Dam pool sediment and prolonged channel widening upstream of t (open full item for complete abstract)

Committee: John Peck Dr. (Advisor) Subjects: Geology

Master of Science, The Ohio State University, 2015, Environmental Science

Fluvial geomorphology is a driver of sediment supply and storage and may therefore affect the accessibility of sediment-bound mercury (Hg) to aquatic organisms, in addition to influencing aquatic food-web structure via physical habitat controls. In particular, benthic insects that in their larval form are aquatic but emerge into the terrestrial environment as winged adults have been shown to be both highly influenced by stream hydrogeomorphology as well as a vector of contaminant transport from aquatic-to-terrestrial systems. Therefore, the potential for fluvial geomorphology to influence both the aquatic-to-terrestrial export of Hg and the potential use of Hg as an aquatic-terrestrial food-web tracer is significant. I first evaluated Hg as a tracer for trophic structure and dynamics for linked stream-riparian systems under differing fluvial geomorphic conditions within a relatively protected watershed. To that end, I investigated potential differences in Hg dynamics and trophic structure between equilibrium (i.e., stable) and adjusting (i.e., unstable) stream reaches as well as the potential for Hg to model linked aquatic-terrestrial food webs at 20 stream-riparian study reaches in Big Darby Creek watershed (OH, USA). At each reach, I conducted geomorphic surveys and sampled sediment, water, benthic and emergent aquatic insects, darters (small, insectivorous stream fish), and two riparian spider families (Tetragnathidae and Pisauridae) for Hg and the stable isotopes 13C and 15N. I provide evidence that fluvial geomorphology may influence Hg availability and aquatic-terrestrial transport (via sediment storage and particle size). Although potential exists for the use of Hg as a food-web tracer, these factors – in addition to opportunistic feeding behavior among consumer groups – may mediate its effectiveness. I next evaluated the influences of fluvial geomorphology on aquatic-to-terrestrial Hg export across a gradient of geomorphic characteristics within an urba (open full item for complete abstract)

Committee: Mazeika Sullivan Dr. (Advisor) Subjects: Environmental Science

MS, University of Cincinnati, 2013, Arts and Sciences: Geology

Modern fluvial systems can be used as ancient river analogs to provide information on the utility of terrestrial plant terpenoids as geologic proxies by defining their potential flux and the processes that control their transport, deposition and degradation in both forested soils and river sediments. Di- and triterpenoids are taxonomically specific terrestrial plant biomarkers, which are produced by conifers and angiosperms, respectively. Because of this source specificity, these compounds are often used in basin-wide reconstructions of paleovegetation. However, the physical and chemical processes that influence the dispersal and sedimentary fate of terpenoids in the geologic record are poorly understood. Here, I quantify di- and triterpenoid concentrations in modern conifer and angiosperm trees, soils, sediments, particulate organic matter and dissolved organic matter in Miners River drainage basin (Upper Peninsula of Michigan) to determine if the contribution of terpenoids from source vegetation is reflected in forested soil and river sediments, and to constrain the dispersal of these compounds in fluvial systems. In the Miners River drainage basin, evergreen conifer trees are less abundant than deciduous angiosperm trees yet contribute substantially more terpenoids to the sediments, when scaled for leaf litter production and present vegetation cover. The ratio of di- to triterpenoids in source vegetation does not match that in forested and river sediments, suggesting that some process, or combination of processes, preferentially removes diterpenoids from sediments. Terpenoids are transported in the particulate and dissolved organic matter fractions in Miners River. Despite potential challenges to reconstructing paleovegetation, sediment terpenoid concentrations can be used to predict the present plant community composition.

Committee: Aaron Diefendorf Ph.D. (Committee Chair); Brooke Crowley Ph.D. (Committee Member); Thomas Lowell Ph.D. (Committee Member); Jodi Shann Ph.D. (Committee Member) Subjects: Geology

Master of Science, The Ohio State University, 2012, Food, Agricultural and Biological Engineering

The goal of this thesis was to develop a better understanding of the drivers of stream equilibrium state in urban settings. Eleven reaches in ten Central Ohio watersheds were surveyed and analyzed to fulfill two specific research objectives: 1.) Create a geomorphology based dynamic equilibrium evaluation index that could determine the equilibrium state of a stream without the use of the bankfull stage and 2.) Determine the key landscape factors that cause a stream to be in or out of equilibrium. Chapter 2 includes the methods and results for research objective one. Geomorphology data from each site was compared using the 1-year and 2-year recurrence interval discharges as well as the top of the bank. A qualitative analysis of the streams led to an initial classification of the study sites into two categories, in equilibrium or out of equilibrium. Binary logistic regression was then used to determine the best model for equilibrium classification. No single model was found to be better than all others. Eight geomorphology variables were found to be significant on their own and two, top of bank to 1-year ratios of discharge and unit stream power, were able to classify 10 of the 11 reaches correctly. Nearly all 2-parameter models were able to predict equilibrium with 100% success. These results show the feasibility of this classification approach, however, tests on a large independent dataset would be necessary to confirm the validity of the models and to choose a single best model. The landscape study to fulfill objective two is discussed in Chapter 3. Three types of landscape factors, urbanization, attachment, and area for adjustment, were explored to determine which indicators would most affect the equilibrium state of the receiving stream. Binary logistic regression was used to compare the landscape data to the qualitative classification from Chapter 2 in order to choose the best equilibrium state predictors. A secondary analysis of a new reach on Rush Run was perfo (open full item for complete abstract)

Committee: Andy Ward PhD (Advisor); Mazeika Sullivan PhD (Advisor); Jon Witter PhD (Committee Member); Jay Martin PhD (Committee Member) Subjects: Environmental Engineering

Master of Arts (MA), Ohio University, 2010, Geography (Arts and Sciences)

Urban development significantly alters the hydrologic and morphologic characteristics of stream channels. Previous research cites impervious surface cover as a primary driving force behind fluvial geomorphic alterations associated with urban development, yet questions remain about the amount of total impervious area (TIA) responsible for subsequent geomorphic modifications of stream systems and about the nature of those modifications. This research compares selected characteristics of 29 rural and 23 urban streams in northern Georgia to determine significant differences in stream hydrology and morphology associated with the expansion of impervious surface cover. Compared to rural (pre-urban) streams, urban streams were found to exhibit greater mean and flood discharges, but no difference in flood stage recurrence interval was found between the two sample groups. Analysis of the urban stream data suggests that a watershed TIA of 14-16% may be an amount of impervious surface cover above which channels become unstable. It is important to establish the level of impervious surface cover associated with alterations to the fluvial system in an attempt to offset the negative fluvial effects of urban development.

Committee: Dorothy Sack PhD (Committee Chair); James Lein PhD (Committee Member); Gaurav Sinha PhD (Committee Member) Subjects: Geography; Hydrology

Master of Science (MS), Ohio University, 2009, Geological Sciences (Arts and Sciences)

The effects of basin hydrology on channel incision and hydraulic adjustments in mountain streams were studied using field data and models of watershed hydrology and channel hydraulics. Conventional theories predict similar channel geometries and hydraulics in the Cherry and Cranberry Rivers because they are adjacent and have similar geologies, climates, and hillslope processes. Unlike the Cherry River, the Cranberry does not conform to traditional ideas about bedrock river incision, which may be explained by its unusual trellis-like, highly elongated watershed morphology. Abrasion is the rate-limiting incision mechanism in the Cranberry because its trellis-like channel network geometry (CNG) causes hydrograph attenuation and comparatively low peak discharges; whereas, the dendritic Cherry River CNG favors plucking due to peaked hydrographs. Restricted flows in the Cranberry River cause downstream fining atop highly resistant sandstones, which maximizes abrasion potentials at the expense of competence.

Committee: Gregory S Springer PhD (Advisor); Dina Lopez PhD (Committee Member); Greg Nadon PhD (Committee Member) Subjects: Geology

Master of Arts (MA), Ohio University, 2008, Geography (Arts and Sciences)

Channel planform change was investigated along 24 kilometers of the Hocking River in Athens County, Ohio, by overlaying aerial photographs spanning 67 years into a geographic information system (GIS) to observe temporal and spatial stream patterns before and after the Army Corps of Engineers modified the river to control flooding in the city of Athens. Previous research has suggested that artificial channel adjustments alter the fluvial geomorphology in the downstream direction by increasing stream volume and stream velocities, causing erosion of the channel and lateral migration of a stream.Channel planform mapping was accomplished through digitizing the fluvial features of a stream and measuring the rates of change. The changes that were observed by the GIS-based methodology show statistically significant changes in the Hocking River channel widths, but little change in lateral migration, except in the asymmetry of meanders bends. Changes in channel width gradually decrease with distance. This lack of change in position and downstream decrease in width suggest that the channelization did not have much impact on the channel planform.

Committee: Dorothy Sack (Committee Chair); James Lein (Committee Member); Margaret Pearce (Committee Member) Subjects: Geography

Master of Science (MS), Ohio University, 2008, Geological Sciences (Arts and Sciences)

Detailed measured sections from the short stratigraphic interval spanning the Pittsburgh to Fishpot Limestone (Late Pennsylvanian) in Athens County, Ohio contain a range of lithologies that are interpreted as a complex suite of continental environments including fluvial (braided, meandering, and anastomosed) and palustrine deposits. Five 4th-order sequences are present based on a model in which interfluve paleosol profiles representing both Falling Stage and Lowstand Systems Tracts, are adjacent to incised braided fluvial deposits representing Lowstand and early Transgressive Systems Tracts (TST). Limestone deposition is mainly restricted to the late TST and was followed by either anastomosed or meandering fluvial deposits of the Highstand Systems Tracts. This model of continental sequence stratigraphy is broadly consistent with a previously published model for 3rd-order relative sea level changes on a passive margin. The variations between the models result from differences in tectonic setting and 3rd-order and 4th-order eustatic rates.

Committee: Gregory Nadon (Advisor) Subjects: Geology

Doctor of Philosophy (PhD), Ohio University, 2004, Plant Biology (Arts and Sciences)

An early phase in the colonization of land is documented by investigation of three fossil compression biotas from Passage Creek (Silurian, Llandoverian, Virginia), Kiser Lake (Silurian, Llandoverian, Ohio), and Conococheague Mountain (Ordovician, Ashgillian, Pennsylvania). A framework for investigation of the colonization of land is constructed by (1) a review of hypotheses on the origin of land plants; (2) a summary of the fossil record of terrestrial biotas; (3) an assessment of the potential of different continental depositional environments to preserve plant remains; (4) a reevaluation of Ordovician-Silurian fluvial styles based on published data; and (5) a review of pertinent data on biological soil crusts, which are considered the closest modern analogues of early terrestrial communities. The three studied biotas are non-paradigmatic biotas, defined here as biotas whose components escape unequivocal taxonomic assignment because their features preclude assignment to any known group, or compare them to several known groups without allowing further distinction. The Passage Creek biota consists of rich, morphologically and anatomically diverse fossil assemblages. They demonstrate that a well-developed groundcover was already present at the beginning of the Silurian, occupying river floodplains. This groundcover consisted principally of thalloid organisms and the diversity of terrestrial communites included cyanobacteria, as well as organisms characterized by complex internal organization, the affinities of which remain unresolved. The Kiser Lake fossils consist of carbonaceous compressions, one of which compares to liverwort leaves and lichen rhizines. The same sediments yield scraps of cellular tissue and the earliest spores assignable to ascomycetes. These are preserved in peritidal carbonate sediments. The Conococheague Mountain biota includes rich compression assemblages from transitional shallow marine and deltaic facies. Such deposits usually harbor mixtures (open full item for complete abstract)

Committee: Gar Rothwell (Advisor) Subjects: Biology, Botany; Paleobotany

Master of Science, Miami University, 2008, Geology and Environmental Earth Science

In the southern Uinta Basin of eastern Utah, fluvial channel sandstones of the Albian-Cenomanian Dakota Formation are economic gas reservoirs. Recovery of gas from the Dakota Formation has proven challenging due to local variability in reservoir sandstone thickness, distribution, and quality. To evaluate the physical characteristics of potential reservoir sandstones, I have constructed two photomosaics of Dakota Formation fluvial channel complexes, measured 13 vertical sections with accompanying outcrop gamma-ray logs, and recorded 1,100 paleocurrent orientations along approximately 40 kilometers of outcrop exposure. Outcrop data were compared with subsurface geophysical/petrophysical and production data to evaluate possible ties between channel sandstone attributes and hydrocarbon occurrence.The primary controls of economic gas accumulation within the Dakota Formation are structure and channel sandstone distribution. Secondary controls include diagenesis and lithology. Amalgamated channels in the lower portions of the Dakota Formation have the greatest potential for economic gas production.

Committee: Brian Currie Dr. (Advisor); John Rakovan Dr. (Committee Member); Jason Rech Dr. (Committee Member) Subjects: Geology

Master of Science (MS), Bowling Green State University, 2012, Geology

Sediments in the lower parts of Ottawa River in Toledo, Ohio have a known history of contamination. Upstream studies have not shown a significant amount of contamination in sediments, but have found some metals present within the fine grained and/or organic material. This contaminated material is easily transported in the suspended load down the Ottawa River. This study addressed transport mechanisms of dissolved and solid phase to determine which was dominate for trace metal and major element concentrations. Filtered and unfiltered water samples were collected from the upper Ottawa River at 3 sites in the Wildwood Preserve Metropark (WW1, WW2, and WW3) and at 2 sites in Secor Metropark (SC2 and SC3). Samples were also collected to determine the total amount of suspended material in the river. Total Suspended Solids (TSS) was analyzed by filtering water samples through coarse, medium, and fine filter paper. Unfiltered water samples were digested following the procedure in EPA method 3105a. All water samples were analyzed for selected major and trace elements using the Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) at Bowling Green State University. Unfiltered sample concentrations were subtracted from filtered sample concentrations to evaluate the solid phase in the suspended load. A Mann-Whitey test of the filtered and unfiltered samples showed there was a significant difference between the two sample types. Discharge was shown as the most significant factor controlling the elemental concentrations through the Principal Component Analysis (PCA) in both the unfiltered and filtered samples. The negative correlations of discharge vs. elemental iii concentrations indicate the influence of groundwater and the positive show the influence of surface water runoff. Discharge was also found to contribute to positive correlations in both the filtered and unfiltered samples for Zn and Sr. The most significant major elements contributing to the variation wer (open full item for complete abstract)

Committee: Sheila Roberts (Advisor); James Evans (Committee Member); Gomezdelcampo Enrique (Committee Member) Subjects: Environmental Geology; Geological; Geology; Geomorphology; Hydrology