Department: Arts and Sciences : Geology ![[clear]](close-x.png "Remove this limiter")
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1.
Adams, Byron A.
Exhumation and incision histories of the Lahul Himalaya, northern India, based on (U-Th)/He thermochronology and terrestrial cosmogenic nuclide dating techniques.
Degree: MS, Arts and Sciences : Geology, 2007, University of Cincinnati
► AHe ages from the Lahul Himalaya show evidence of exhumation over the…
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▼ AHe ages from the Lahul Himalaya show evidence of exhumation over the past 2.5 Ma, with younger cooling ages occurring on mountain peaks and older ages in valley floors. These data imply an exhumation pattern that decreases topographic relief. Two cases can be argued: (1) Lahul has been experiencing a period of high denudation during the Late Neogene and this rate has out paced any uplift that may also have occurred. (2) There has been no rock uplift in Lahul during the Late Neogene and even moderate amounts of denudation are able to decrease topographic relief. Terrestrial cosmogenic nuclide Be10 ages of strath terraces in of the Chandra River show 5.36±0.17 ka of incision history. Incision rates varied from 1.69 to 12.22 mm/yr during this time. This may imply that the active processes of Lahul (e.g. waning glacial activity, mass wasting, the monsoon) are in a dramatic state of disequilibrium.
Advisors/Committee Members: Dietsch, Dr. Craig W.
Subjects: Geology
Keywords: Lahul; Himalaya; exhumation; incision; thermochronometry; terrestrial cosmogenic nuclides; strath terraces
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2.
Agnello, Tim Joseph.
Land Use and Landsliding in Price Hill, Cincinnati, Ohio.
Degree: MS, Arts and Sciences : Geology, 2002, University of Cincinnati
► An engineering geology study of chronic landsliding on a 168-acre hillslope on…
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▼ An engineering geology study of chronic landsliding on a 168-acre hillslope on the western side of Mill Creek Valley in Price Hill, Cincinnati, Ohio finds that most of the landsliding can be associated with past land use initiated over the last 195 years. The majority of the hillside has moved or is in quasi-equilibrium from human activity. Historic quarry operations, deforestation, clear cutting, grading for housing (both historic and ongoing), road construction, loading of the slope from dumping (landfill, construction debris, etc), and modification of the natural hydrology have set the stage for past and ongoing destabilization of the hillside. Research of past land use patterns and examination of historic photographs, maps, newspaper accounts, directories, and books complemented mapping of human landforms, instability features, and surface water drainage. The majority of the study data was collected in the field however; historical documentation revealed landsliding and/or preexisting human made features that today would not be recognized in a traditional field investigation. Additionally, some of the landforms identified in the study area could be validated as landslide or human made features by examination of the historical data. Examination of the historic record and past human landforms that at present may be completely or partially indistinct gives a different perspective on the extent of hillside instability. A stake survey combined with inclinometers may be necessary to delineate the true extent of ground movement in areas absent of human made earthen landform, structure, or lacking historical data, especially on the lower portions of the hillslope where the overburden thickens. Thorough examination of the historic record in conjunction with a careful field study of the amount of hillside disturbance and movement allows the public and professionals to make prudent decisions on future hillside use and development. Further, Geographical Information Systems (GIS) provided a vehicle to preserve the field data (mapped at 1:1200) and land use patterns for future reference.
Advisors/Committee Members: Nash, Dr. David.
Subjects: Geology
Keywords: Land use and landsliding in Cincinnati, Ohio; Tim Agnello Geology; Engineering geology, Price Hill; Geographical information systems, GIS, CAGIS; Cincinnati rock quarry, quarries
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3.
Ballard, Joanne P.
A Lateglacial Paleofire Record for East-central Michigan.
Degree: MS, Arts and Sciences : Geology, 2009, University of Cincinnati
► This study provides a lateglacial paleofire record for Michigan which will help…
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▼ This study provides a lateglacial paleofire record for Michigan which will help to reconstruct the larger geographic pattern of fire during lateglacial time, as very few charcoal studies have been carried out for the Midwest. This work will be integrated into the Global Charcoal Database at the World Data Center for Paleoclimatology for future studies relating to fire patterns and regions, and vegetation and climate change. This study was initially designed to test the biomass burning aspect at 12,900 BP of the Firestone et al. (2007) extraterrestrial impact hypothesis. Four lakes near Flint Michigan were sampled because of their proximity to the Gainey Paleoindian site featured in the Firestone et al. (2007) paper. Charcoal was quantified in these four lakes to develop a multi-site lateglacial fire record for the Midwest. The results show contemporaneous fire not only at 12,900 BP but multiple times between 14,500 and 12,900 BP. This synchronicity of the fires between 14,500 and 12,900 BP suggests some as-yet-indeterminate large-scale natural cause, or causes. From 12,900 BP on into the Holocene, the pattern changes. Fires are continuous with high charcoal peaks at Swift Lake, continuous at Slack Lake but with slightly lower charcoal peaks compared to Swift, and having much lower peaks at Lake Sixteen and Big Fish Lake (charcoal is present but at very low levels). This pattern is interpreted to be a result of the distance from the Paleoindian site. Swift and Slack Lakes are each less than one km from the Gainey site, while the other two lakes are 30 km and 16 km away from it. The disparity of the amplitude of the signals in the fire patterns between the two pair of lakes from 12,900 BP forward in time suggests Paleoindian origin for fire. Additional radiocarbon dates are needed to refine the chronology of the timeline and gain a better understanding of the sedimentation rate. More charcoal research should be conducted on lakes across a larger region, for the interval from the Last Glacial Maximum into the Holocene.
Advisors/Committee Members: Lowell, Thomas.
Subjects: Archaeology; Astrophysics; Cultural anthropology; Earth; Ecology; Forestry; Freshwater ecology; Geology; Paleobotany; Paleoecology; Paleontology
Keywords: paleofire; fire; lateglacial; Paleoindian; Gainey; Younger Dryas; late Pleistocene; extraterrestrial; impact; mastodon; Michigan; Midwest; charcoal; Swift Lake; Slack Lake; Big Fish Lake; Lake Sixteen; wildfire
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4.
Barbour, Susan Leigh.
Microstratigraphic Analysis of an Amalgamated Horizon in the Type Cincinnatian:Implications for Spatio-Temporal Resolution in the Fossil Record.
Degree: MS, Arts and Sciences : Geology, 2002, University of Cincinnati
► Studies of modern storm processes indicate that post-mortem transport of benthic marine…
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▼ Studies of modern storm processes indicate that post-mortem transport of benthic marine organisms is often negligible, suggesting that subfossil death assemblages may commonly preserve spatial community structure with good fidelity, albeit time-averaged. To test the implication that the same fidelity is to be expected in ancient assemblages, the Upper Ordovician strata of the type Cincinnatian provide highly fossiliferous, laterally extensive outcrops that are ideally suited for assessing fine-scale spatial and temporal patterns in a storm-dominated setting.For this research, I analyzed spatial and microstratigraphic patterns of fossil distribution preserved in an amalgamated, multi-event horizon that is traceable for a lateral distance of some 60 km. A previous study of this horizon, contained in the lower Fairview formation, suggested that biologically meaningful spatial variation was preserved down to the 10 m scale, despite extensive storm reworking of the unit. However, in the earlier study, no effort was made to assess variation among the microhorizons that comprise the bed. By contrast, I conducted a microstratigraphic dissection of samples collected at 1- and 10-m lateral scales along a 150-m transect at the primary, “anchor” locality. Collections were also made of the same horizon at four additional localities arrayed throughout the study area. Collectively, the within- and between-outcrop sampling permitted assessment of spatial variability at scales ranging from 10 0 to 10 4 meters. Analysis of the 72 bulk samples (5,150 specimens) indicated that a subtle gradient is present at the anchor locality. Statistical analyses demonstrated that greater heterogeneity was preserved among the samples than can be expected by chance. In several instances, microhorizons within a given bulk sample of the entire interval maintained a consistent biotic composition distinguishable from that of adjacent samples, suggesting that in some instances, fine-scale spatial signals were preserved through several storm events. Thus, non-random spatial variability appears to be preserved in these ancient fossil assemblages, despite the myriad of storms and other post-mortem processes that may affect faunal assemblages between death and final preservation. Furthermore, the discovery of a consistent stratigraphic signal through several microhorizons suggests that biological patchiness on the Ordovician sea floor sometimes survived the effects of several storms.
Advisors/Committee Members: Miller, Dr. Arnold I.
Subjects: Paleontology; Geology
Keywords: ordovician; paleontology of paleobiology; faunal analysis; stratigraphy; brachiopods and bryozoans
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5.
BARTHOLOMEW, ALEXANDER.
CORRELATION OF HIGH ORDER CYCLES IN THE MARINE-PARALIC TRANSITION OF THE UPPER MIDDLE DEVONIAN (GIVETIAN) MOSCOW FORMATION, EASTERN NEW YORK STATE.
Degree: MS, Arts and Sciences : Geology, 2002, University of Cincinnati
► The upper Middle Devonian (Givetian) Moscow Formation of the Hamilton Group was…
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▼ The upper Middle Devonian (Givetian) Moscow Formation of the Hamilton Group was deposited in a subsiding foreland basin north of the advancing Acadian Highlands. The Moscow Formation overall represents a third-order cycle of relative sea-level variation that contains six and one-half subsequences of sea-level fluctuation, regarded as fourth-order cycles. Smaller-scale subsequences of the Moscow Formation have previously been correlated east to the Oneonta area in Otsego Co. Correlations were carried eastward to Schenevus and Summit and then the Schoharie Valley. Definite identification of these subsequences is possible to Summit. Eastward of Summit, the overall pattern of relative sea-level oscillation is still discernable, although the distinguishing characteristics of the subsequence have changed. Third-order cycle of sea-level oscillation represented by the Moscow Formation displays an overall shallowing-to-deepening-upward trend in the western portions of New York State. This pattern switched to a shallowing-upward pattern in the Schoharie Valley, with the upper portion of the Moscow Formation being represented by terrestrial floodplain sediments. This change in pattern is due to a switching from allocyclic (eustatic) control on deposition in the west to control by autocyclic (deltaic) processes in the east. Although the third-order pattern of deposition has changed in the Moscow Formation in the Schoharie Valley, the pattern of the fourth-order cycles can still be discerned, indicating that eustatic sea-level fluctuation still exerts control on deposition. Five levels of the Gilboa Forest are found to be contained within the Moscow Formation. The stumps of progymnosperm trees were found to be encased within the sandstones that correlate to the transgressive portions of the subsequences in the west. Correlation of subsequences of the Moscow Formation into this region allows for a more detailed analysis of the contact between the Moscow Formation and the Tully Formation. Above the uppermost subsequence of the Moscow Formation in this region is about 60 meters of redbeds that have previously been assigned to the Moscow Formation. These can now be shown to be equivalent to the deposits of the lower and middle Tully Formation in the west, with the overlying Gilboa Formation equivalent to the upper Tully and overlying Genesee formations.
Advisors/Committee Members: Brett, Dr. Carlton E.
Subjects: Geology
Keywords: stratigraphy; sequence stratigraphy; paleontology; correlation; paleo botany
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6.
BARTHOLOMEW, ALEXANDER JESS.
MIDDLE DEVONIAN FAUNAS OF THE MICHIGAN AND APPALACIAN BASINS: COMPARING PATTERNS OF BIOTIC STABILITY AND TURNOVER BETWEEN TWO PALEOBIOGEOGRAPHIC SUBPROVINCES.
Degree: PhD, Arts and Sciences : Geology, 2006, University of Cincinnati
► The hypothesis of Coordinated Stasis, developed from observations of extended periods of…
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▼ The hypothesis of Coordinated Stasis, developed from observations of extended periods of faunal stability in Middle Devonian sediments of the Appalachian Basin, has been the topic of intense research in recent years in the field of paleoecology. Investigations into patterns of faunal persistence have been conducted on various sedimentary basins throughout the rock record; however no study has yet attempted to document concurrent faunal patterns in separate paleobiogeographic regions. The Middle Devonian Appalachian and Michigan basins provide a perfect test case for an examination of coeval patterns of faunal change as they were separate paleobiogeographic subprovinces at this time. Patterns of faunal turnover were examined in the Michigan Basin and compared to the well-documented record the coeval Appalachian Basin. In order to compare patterns at a fine scale, correlations between the Appalachian and Michigan Basins were refined using sequence stratigraphic criteria resulting in a high-resolution stratigraphic framework between the basins. It was possible to correlate both large- and small-scale sequences between the basins indicating the primary control on deposition across much of eastern North America was eustatic sea level oscillation. It was also possible to constrain the timing of tectonic activity between the basins as well as refine the biostratigraphy of the interval. Three separate faunal intervals were identified as having existed in the Middle Devonian in the Michigan Basin and were determined to be analogous to the Evolutionary Ecological (EE) Subunits of the Appalachian Basin Middle Devonian; the timing of faunal turnover between the EE Subunits was coeval between the basins. The degree of taxonomic mixing between the basins was also examined at the level of 3rd-order depositional sequence through the duration of the Hamilton-Traverse EE subunit using the Jaccard similarity coefficient indicating greater amounts of mixing between the basins at the beginning and end of the interval with more restricted mixing in the middle of the interval. Comparison of biofacies replacement through time was examined at a fine scale through a single 3rd-order sequence in the Appalachian Basin, the Michigan Basin, and an intermediate region using Detrended Correspondence Analysis yielding similar patterns through time in all areas.
Advisors/Committee Members: Brett, Dr. Carlton E.
Keywords: Coordinated Stasis, Faunal Stability, Faunal Turnover, Middle Devonian, Sequence Stratigraphy, Eifelian, Givetian, Michigan Basin, Appalachian Basin
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7.
BERTOG, JANET LYNN.
HIGH RESOLUTION EVENT STRATIGRAPHIC AND SEQUENCE STRATIGRAPHIC INTERPRETATION OF THE LOWER PIERRE SHALE (CAMPANIAN) WITH THE DESCRIPTION OF THE NEW WALHALLA AND CHAMBERLAIN MEMBERS.
Degree: PhD, Arts and Sciences : Geology, 2002, University of Cincinnati
► The lower Pierre Shale represents a time of significant changes in the…
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▼ The lower Pierre Shale represents a time of significant changes in the Cretaceous Western Interior Seaway, resulting from a complex interplay of tectonic events and eustatic sea level changes. Volcanic activity along the western margin of the seaway produced large volumes of ash that are recorded in the sediments of the basin in the form of bentonites. The bentonites provide information useful in interpreting volcanic activity that was active as well as providing event horizons in the strata that are useful for high-resolution stratigraphic analysis. Bentonites of the lower Pierre Shale indicate that at least three major sources were active during this period, corresponding to forearc, island arc and backarc magmatism, as indicated by trace element whole rock geochemical signatures. Mineralogical suites of these bentonites indicate that both andesitic and rhyolitic sources were present within these major regions. Biotite phenocrysts further segregated magmatic sources of the bentonites. Based on the composition of the bentonites, several individual layers of bentonite can be identified in the lower Pierre Shale. These bentonite horizons, combined with biostratigraphic correlation have provided high-resolution detailed stratigraphic evaluation of the lower Pierre Shale across the basin. The newly defined Walhalla Member represents a tectonically influenced sequence that precedes the eustatic sea level rise recognized as the Claggett Cycle in the Western Interior. The Walhalla Member is restricted to the northern part of the basin, where tectonic activity resulted in increased subsidence of the axial basin and the Williston Basin prior to the eustatic sea level rise. Following the Walhalla Member, eustatic sea level rise resulted in the deposition of the Sharon Springs and the Chamberlain members on the eastern stable platform while the Mitten Black Shale Member was deposited in the axial basin. Recognition of these distal sequences is necessary in order to understand the complete basin dynamics.
Advisors/Committee Members: Huff, Dr. Warren.
Subjects: Geology
Keywords: Pierre Shale; Sharon Springs; sequence stratigraphy; bentonite; Walhalla Member
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8.
Bezusko, Karen M.
Biotic Interaction Versus Abiotic Response as Mediators of Biodiversity in the Middle Devonian (Givetian) Upper Hamilton Group of New York State.
Degree: MS, Arts and Sciences : Geology, 2001, University of Cincinnati
► A noteworthy transition in global biodiversity of benthic marine faunas was initiated…
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▼ A noteworthy transition in global biodiversity of benthic marine faunas was initiated during the mid-Paleozoic, in which burrowing deposit feeders (BDF) began to increase in taxonomic richness, while, simultaneously, immobile suspension feeders that lived on soft substrates (ISOSS) began to decrease. The factors governing such large-scale faunal patterns have long been debated among paleontologists-do they result from biological interactions, responses to physical transitions, or both? The Middle Devonian Hamilton and Upper Devonian Sonyea Groups of New York State provide ideal backdrops for addressing this question because of their diverse, well-preserved benthic marine fossils belonging to both groups (BDF and ISOSS) contained within strata that recorded changes in sedimentation associated with the Acadian orogeny. Faunal censuses were taken at sixteen localities on a west to east transect from Buffalo to Albany, New York, stratigraphically spanning the Ludlowville and Moscow Formations of the upper Hamilton Group. Genus-level data subjected to multivariate statistical analyses reveal a strong lithofacies control on the biota. Limestones and calcareous mudstones and shales contain diverse ISOSS faunas including crinoids, bryozoans, corals, and a variety of articulate brachiopods. Siltstones and sandstones are more heavily bioturbated based on numbers of burrows and trace fossils (Zoophycos), and contain more nuculoid bivalves, all recognized as BDF. Additionally, there is a clear geographic constraint on faunal variation that correlates with the configuration of the Appalachian Basin of the Middle Devonian. Although ISOSS organisms dominate all faunal assemblages in both abundance and taxonomic richness, ISOSS organisms were most abundant on the carbonate ramp, west of the central trough, while BDF were most abundant in the eastern siliciclastic-rich environments. The strong correlation between the fauna and sediments in which they are found suggests that, as the Catskill wedge prograded westward through the Upper Devonian, so would BDF-dominated communities. Data assembled from the literature for the Triangle and Glen Aubrey Formations of the Sonyea Group do not show increases in abundance or taxonomic richness for BDF organisms. Based on the results from multivariate analyses, the mechanism behind faunal variation in the Middle and Upper Devonian of New York appears to be regional physical conditions.
Advisors/Committee Members: Miller, Arnold I.
Subjects: Paleoecology; Paleontology
Keywords: BIODIVERSITY; BIOTIC INTERACTION; ANIMAL-SEDIMENT RELATIONSHIPS; HAMILTON GROUP; DEVONIAN
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9.
BONELLI, JAMES JR. R.
TESTING FOR PALEOCOMMUNITY RECURRENCE ACROSS A REGIONAL BIOTIC TURNOVER EVENT IN THE MIDDLE DEVONIAN HAMILTON GROUP AND TULLY FORMATION OF NEW YORK AND PENNSYLVANIA.
Degree: MS, Arts and Sciences : Geology, 2003, University of Cincinnati
► A persistent paleoecologic issue concerns the extent to which species form integrated,…
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▼ A persistent paleoecologic issue concerns the extent to which species form integrated, recurring units through time, or, alternatively, loosely-structured ephemeral associations. Underlying this question has been the hypothesized pattern of taxonomic and ecologic stability punctuated by rapid biotic reorganization, referred to as “coordinated stasis”. While it was first recognized formally in the Middle Devonian Appalachian Basin, and documented in detail, little research has focused on the degree of “internal” variation among biofacies within this “type area”. This study tests recurrence among two coral biofacies across a regional biotic turnover event in the Middle Devonian Appalachian Basin. Species abundance data were collected to permit faunal comparisons among samples from single localities, localities within regions, and regions across the basin. Significant variation in biotic composition was detected at all scales in these analyses. Although species membership was comparable, dominance structures varied greatly among units, indicating that “biofacies” were not persistent, unchanging units.
Advisors/Committee Members: Brett, Dr. Carlton.
Subjects: Paleoecology; Paleontology
Keywords: Middle Devonian; coordinated statis; Hamilton group; South Lansing coral bed; West Brook bed
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10.
BONILLA, ALEJANDRA.
GEOCHEMISTRY OF ARSENIC AND SULFUR IN SOUTHWEST OHIO: BEDROCK, OUTWASH DEPOSITS AND GROUNDWATER.
Degree: MS, Arts and Sciences : Geology, 2005, University of Cincinnati
► Located in southwest Ohio, the Mason and also the Lebanon Correctional Institute…
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▼ Located in southwest Ohio, the Mason and also the Lebanon Correctional Institute drinking water distribution systems obtain their water from the Shaker Creek “buried valley” Aquifer. The Pleistocene valley contains glacial outwash material and some lake clays incised into the limestone-shale bedrock. Analyses were done in water, aquifer material and bedrock samples. The results of arsenic in water ranged from 4-18 µg/L, and show that many of these samples are above the USEPA MCL. Thus, both systems have concerning arsenic levels. Arsenic analyses in the bedrock and glacial outwash material ranged from 4-40 ppm. Therefore, arsenic in the groundwater could be sourced from the glacial aquifer material and/or from the surrounding bedrock. The bedrock geology of the area of study consists of Upper Ordovician-Lower Silurian limestones and shales of southern Ohio and northern Kentucky. The bedrock formation studied and that partly influence the water chemistry in the Shaker Creek buried aquifer is the Kope Formation. Stable isotope analysis of sulfur was used for this study. Many of the geochemical characteristics of arsenic are analogous to those of sulfur. Biogenic reduction is the dominant form of sulfur fractionation in nature and is mainly a product of sulfur reducing bacteria. The present thesis is focused in two main parts. First part covers the study of arsenic in solids and sulfur isotopes were used to calculate sedimentation rates in the Kope Formation. Second part includes the study of arsenic in groundwater and its source in the Shaker Creek Aquifer. This study presents a model of the possible sources and mechanisms of arsenic in groundwater. Sulfur isotopes were used to provide a chemical assessment and a comparison of sulfur isotopes in the bedrock with dissolved sulfur in the aquifer as a test for arsenic release by pyrite dissolution.
Advisors/Committee Members: Maynard, Dr. Barry J.
Subjects: Geology
Keywords: arsenic, sulfur isotopes, Kope Formation, Shaker Creek Aquifer, buried valley aquifer, groundwater.
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11.
Bries, Jill M.
THE IMPACT OF HURRICANE LENNY ON CORAL REEFS AND ITS RELEVANCE TO PLEISTOCENCE REEF COMMNUNITIES: CURACAO, NETHERLANDS ANTILLES.
Degree: MS, Arts and Sciences : Geology, 2001, University of Cincinnati
► Storms such as hurricanes can dramatically impact a coral reef. In November…
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▼ Storms such as hurricanes can dramatically impact a coral reef. In November 1999, Hurricane Lenny traveled an unusual west to east path across the central Caribbean approximately 480 kilometers north of the island of Curaçao. Reef damage surveys at 33 sites conducted just months after the storm documented occurrences of toppling, fragmentation, tissue damage, bleaching, and smothering due to the storm. Several factors influenced the degree of damage experienced by the reef, including the trend of the shoreline, coral growth form, colony size, and water depth. Curaçao's location outside of the major hurricane belt and well south of the track of Hurricane Lenny shows that rarely disturbed reefs can incur significant damage by storm-generated waves that travel across a great distance. Pleistocene reef communities on the island preserve the same species of corals and reef zonation present on many modern reefs throughout the Caribbean. Transects conducted along the fossil reefs show that different reef paleoenvironments (reef crest vs backreef) have different relative abundances of components. These different environments also preserve corals in the position of growth to differing extents. Many large coral colonies are preserved in growth position with the presence of few or no encrusting or boring organisms. These observations suggest a very rapid burial, possibly associated with a major regression while the corals were still alive. Although storm features on modern reefs, such as toppling and fragmentation, may potentially be preserved in the Pleistocene reefs of Curaçao, these features are difficult to differentiate from those that were produced by other natural day-to-day processes such as bioerosion and processes involved with a rapid regression, including large-scale movement of sands from nearshore beaches or dunes.
Advisors/Committee Members: Meyer, David.
Keywords: CORAL REEFS; HURRICANE DAMAGE; PLEISTOCENE REEFS; TAPHONOMY; CARIBBEAN
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12.
BROCKMAN, TRACY.
Dynamics of Cooling and Plagioclase Crystallization in a Feeder Dike of the Columbia River Flood Basalt Group.
Degree: MS, Arts and Sciences : Geology, 2008, University of Cincinnati
► Image analysis of crystal sizes for plagioclases from a basaltic trachy-andesite feeder…
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▼ Image analysis of crystal sizes for plagioclases from a basaltic trachy-andesite feeder dike of the Columbia River Flood Basalt Province yields a linear relation when the natural log of the number of plagioclase crystals of a given size interval per volume is plotted against L (cm). The slope of this line, −(1/Gτ), is related to the plagioclase growth rate, G (cm/sec), and the magma residence time, τ (seconds). For one sample, an observed slope of −5.0329 corresponds to values of τ of 1.9 years, determined using conductive cooling equations. The derived value for G is 1∗10−8.9 cm/sec, in good agreement with previously published results for the plagioclase growth rates found for larger basaltic magma bodies.
Advisors/Committee Members: Kilinc, Attila.
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13.
Buick, Devin P.
The Rise and Fall of the Cucullaeidae: Exploring Transitions in Species Richness, Geographic Range, Morphology and Ecology in a Relict Bivalve Family.
Degree: PhD, Arts and Sciences : Geology, 2010, University of Cincinnati
► The bivalve family Cucullaeidae has persisted for the past 200 million years,…
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▼ The bivalve family Cucullaeidae has persisted for the past 200 million years, with shifts in species richness, geographic range and morphological disparity occurring in response to extrinsic and intrinsic evolutionary pressures and opportunities. The purpose of this dissertation is to investigate the evolutionary trajectory of the cucullaeids in detail, by integrating multiple analytical approaches towards assessing changes in biodiversity, biogeography and morphology. As one element of the Jurassic radiation of bivalves generally, and of arcoid bivalves specifically, the Cucullaeidae initially diverged morphologically from their ancestors through modification of their taxodont dentition into distinct sets of central and lateral hinge teeth, which enabled early cucullaeid species to live in semi-infaunal, endobyssate life habits. Facing unique functional obstacles to the infaunal adaptive zone, the family continued to evolve morphologically throughout the Jurassic and Early Cretaceous, most notably employing an innovative, internal flange to facilitate lengthening of the posterior margin, to eventually become the first, post-Paleozoic arcoid group to diversify into fully-infaunal, free-burrowing life habits. Based on a distinctive, powerfully-interlocking hinge structure, this morphological shift and expansion was paralleled by increases in species richness and geographic range. By the Late Cretaceous the family was represented by many species (~65) distributed throughout warm-water, sandy environments across the globe. During this diversity peak, innovative patterns of external sculpture within the “core” genus Cucullaea , along with extreme modifications to shell features and overall form among other cucullaeid genera, pushed the morphological limits of the family and expanded its adaptive range. Following the extinction and lack of replacement of many species, the number of cucullaeid species plummeted into the early Cenozoic, especially for once highly-diverse assemblages in North America and Europe. At that time the family is composed primarily of large-bodied taxa, which utilized their size for enhancing stability in the substrate and avoiding the risk of excavation. Now represented entirely by the genus Cucullaea , the family maintained its worldwide distribution throughout much of the Paleogene, but a continued decline in global temperature eventually resulted in the extripation of individual species and, indeed, the entire family from several continents. This winnowing has continued to the present day, where the range and diversity of the group is a relict of a once richer past. Yet the family persists with four surviving extant species, and, beginning in the Miocene, has radically altered multiple aspects of the long-established cucullaeid body plan. Reduction to the hinge plate, ligament grooves, shell thickness and external sculpture, in conjunction with a maintenance of large body size and elaboration of the posterior flange, has completely shifted the family into new morphological territory, rivaling the Jurassic-to-Cretaceous transition whereby elongate-shaped, endobyssate species were replaced by trapezoidal, free-burrowing forms. In light of the prolonged morphological evolution of the Cucullaeidae, the magnitude of this recent shift is impressive, with the persistence of this relict family relying on the survival of and expansion around this modern morphotype.
Advisors/Committee Members: Miller, Arnold.
Subjects: Geology
Keywords: Morphology; Macroevolution; Cucullaea; Biogeography; Biodiversity; Morphometrics
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14.
BULINSKI, KATHERINE VICTORIA.
Relationship of sample-level properties to biodiversity at multiple scales: analyses of Upper Ordovician and Cenozoic ecological and latitudinal gradients.
Degree: PhD, Arts and Sciences : Geology, 2008, University of Cincinnati
► The study of fossil biodiversity has persisted as a major theme in…
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▼ The study of fossil biodiversity has persisted as a major theme in paleobiological research throughout the last three decades. As researchers attempt to characterize regional and global assessments of diversity through time, large volumes of data from across many regions are amalgamated into singular measures of taxonomic richness. While these large-scale studies are useful for exploring and characterizing major transitions in the history of life, investigations of small-scale variations in paleontological communities through space and time may also be relevant to these patterns, helping to explain how sample and local-level biodiversity assessments aggregate into regional and global patterns.This research investigates variation in properties of biodiversity across several scales using two different gradients as backdrops; 1) a paleoecological depth gradient in the Upper Ordovician type Cincinnatian and 2) the strengthening Cenozoic latitudinal diversity gradient in the western Atlantic. While these two systems are very different with respect to their taxonomic composition and physical parameters, the basic underlying components of fossil diversity are the same in both cases. These components were investigated in several ways, ranging from the behavior of evenness and the nature of rarity as functions of the Cincinnatian depth gradient to variation in the proportion of rare taxa through space and time through an interval of global cooling during the Cenozoic. In the type Cincinnatian, evenness and rarity were evaluated as functions of sample size and geographic area within a constrained stratigraphic and geographic system, allowing for definitive recommendations for the type of evenness metric that should be used and the amount of sampling necessary for characterizing these components of biodiversity within fossil communities. Additionally, a new method was applied in this research that involved use of the proportion of rare taxa as a distinct compositional unit for exploring variation in taxonomic richness with respect to both the depth and latitudinal gradients. This unprecedented technique revealed an apparent increase in rare genera in the tropics as a function of the strengthening latitudinal gradient, whereas no apparent trend in rarity was found along the Cincinnatian depth gradient.
Advisors/Committee Members: Miller, Arnold.
Subjects: Ecology; Geology; Paleoecology; Paleontology
Keywords: fossil biodiversity; richness; evenness; Cincinnatian; rarity; ecological gradient; latitudinal diversity gradient
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15.
Bullard, Reuben G. Jr.
Estimation of Slope Erosion Rates from 10Be Nuclide Accumulation: A Northern Kentucky Example.
Degree: MS, Arts and Sciences : Geology, 2001, University of Cincinnati
► Mathematical treatment of the evolution of landscapes requires estimates of the rate…
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▼ Mathematical treatment of the evolution of landscapes requires estimates of the rate of surface change. This project uses cosmogenic 10Be accumulation measurements to obtain estimates for erosion rates on upper and slope surfaces of a stream-dissected landscape in a temperate climate, low elevation environment. Laurentide glacial outwash sediments in northern Kentucky provide a study site situated at a migrating nickpoint that results from Ohio River base level adjustment following Quaternary disruption and diversion of drainage. This site permits examination of the small-scale (20,000 sq. meters) relationship between different elements of an evolving landscape. Samples were recovered from two transects on the crest, upper slope, and lower slope of a tributary stream of Gunpowder Creek. 10Be concentrations determined by accelerator mass spectrometry were related to erosion rates following the methods described by Brown, et al, (1995), Granger, et al, (1996) and others. Estimates for erosion of the crest suggest rates of 6.07x10-4 and 6.71x10-4 cm/yr. (~6m/my) while those for the slope range from 5.86x10-3 and 3.16x10-3 cm/yr. (~30-60m/my). This inplies that the slope is eroding ~5-10 times faster than the crest. These long-term rates reflect slope response to relatively rapid erosion in a zone of steepness (nickpoint). Consolidated sediment is one factor which may limit locally erosion. It is evident, however, that erosion rates increase dramatically once a surface becomes inclined. The nickpoint zone of a developing slope represents an early phase of slope evolution, marked by slope steepening approaching the angle of repose for unconsolidated sediment and forming local bluffs of consolidated sediment.
Advisors/Committee Members: Lowell, Thomas V.
Subjects: Geology
Keywords: EROSION RATE; LANDSCAPE EVOLUTION; COSMOGENIC ISOTOPE; SLOPE; BERYLLIUM ISOTOPE
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16.
Cornell, Sean Richard.
Sequence Stratigraphy and Event Correlations of Upper Black River and Lower Trenton Group Carbonates of Northern New York State and Southern Ontario, Canada.
Degree: MS, Arts and Sciences : Geology, 2001, University of Cincinnati
► Successions of carbonate to mixed carbonate/siliciclastic rocks of Middle Ordovician age were…
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▼ Successions of carbonate to mixed carbonate/siliciclastic rocks of Middle Ordovician age were deposited in New York State and Ontario, Canada on the passive edge of the westward advancing Taconic foreland basin. The transition from carbonate to siliciclastic sedimentation is thought to record the critical change from a passive to active tectonic margin. In addition to tectonic change, it has been suggested that this stratigraphic interval also records an overall transgressive series (Tippecanoe megasequence Sloss, 1963) which is interrupted by shorter duration sea-level fall events (Holland and Patzkowsky, 1996, 1998). Holland and Patzkowsky (1996, 1998) delineated 6 sequences for the Mohawkian and correlated these sequences in the southern Appalachians, Nashville Dome, and Cincinnati Arch. However, the succession in New York and Ontario have not been equally evaluated within this framework. Herein, the upper Black River to lower Trenton groups are investigated in order to help understand the event and cyclic stratigraphic relationships of units recognized throughout the outcrop belt from southern Ontario, Canada, to northern New York State and to place these rocks into a sequence stratigraphic framework. Through the use of correlated event beds including K-bentonites, and other marker horizons it has been possible to delineate a series of 2 depositional sequences, with distinctive systems tracts, and small-scale parasequences (or PACs) that are correlatable across the New York-Ontario region. By establishing these correlations it has been possible to provide objective criteria for defining a new position for the Black River/Trenton Group lithostratigraphic boundary in this region, such that it also represents a significant chronostratigraphic boundary as well. In addition to establishing local to regional correlations, through the association of K-bentonites it has also been possible to infer the positions of two of Holland and Patzkowsky's (1996) sequences in the study region. Although the association of Holland and Patzkowsky's M4 and M5 sequences is preliminary, several key issues are raised that support the need for a revision of the North American chronostratigraphic nomenclature as applied outside the New York/Ontario type region.
Advisors/Committee Members: Brett, Carlton E.
Subjects: Geology
Keywords: K-BENTONITES; ORDOVICIAN; TURINIAN; CHATFIELDIAN; SEQUENCE STRATIGRAPHY
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17.
Cornell, Sean Richard.
The Last Stand of the Great American Carbonate Bank: Tectonic Activation of the Upper Ordovician Passive Margin in Eastern North America.
Degree: PhD, Arts and Sciences : Geology, 2008, University of Cincinnati
► The Upper Ordovician (450-460 Ma) Chazy, Black River and Trenton groups of…
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▼ The Upper Ordovician (450-460 Ma) Chazy, Black River and Trenton groups of eastern North America record the tectonic activation of a passive carbonate platform. Associated with tectonic collision and development of a peripheral-type foreland basin, the tectonic history is complicated by the occurrence of two basin-forming episodes. Although considered analogous by previous authors, a growing list of observations indicate that the stratigraphic record from both foreland basins and their coeval Great American Carbonate Bank (GACB) contain somewhat different, non-analogous, signatures. A number of key issues arise when comparing both tectonic episodes. These include: 1) non-analogous spatial-temporal scales whereby the northern (Vermontian) tectophase is much larger and of longer duration compared to the southern (Blountian) tectophase; 2) sedimentary provenance analyses show a more mafic contribution in the northern basin fill compared to that of the southern basin; 3) the position of K-bentonite swarms relative to basin filling phases is non-analogous; and 4) the location and timing of Ordovician volcanism/plutonism shows a pronounced change after the first tectophase. Thus, important research questions for this study include: A) How does the architecture of the foreland basin complex and adjacent GACB change spatially and temporally during each distinct tectophase?; B) Can provenance differences between tectophases be explained relative to tectonic events in the orogen?; C) What is the timing and significance of K-bentonite position and timing of plutonism/volcanism relative to foreland basin fill episodes?; 4) What inferences are gained from theoretical modeling of load geometries and foreland basin evolution when considered with empirical data from the Taconic Orogeny; and 5) Is a new model for the Taconic Orogeny needed to explain the growing list of incongruities? In order to investigate these questions, a refined, high-resolution, sequence stratigraphic framework has been constructed and utilized to re-calibrate Upper Ordovician strata during the last stand of the GACB. The refined framework was constructed using the occurrence of sequence boundaries, erosional surfaces, transgressive, highstand, and regressive systems tracts, hardgrounds and flooding surfaces, laterally extensive and unique lithofacies, highly repetitive sub-meter scale cyclic intervals, updated macrofaunal and microfaunal biostratigraphies, as well as known chemostratigraphic and event stratigraphic data (Nd, C, & Sr isotopic excursions, K-bentonite horizons, seismite horizons, etc.). Also defined for the first time are a number of time-restricted facies including widespread siliciclastic events, chert-rich intervals, and pronounced calcification events. As such, an improved temporal and spatial chronology of thirteen time-slices (~ 1 million year duration) has been produced for the Ashbyan, Mohawkian, to earliest Cincinnatian interval. This integrated stratigraphic model is used to link the sedimentary record of the foreland basin complex to climatic changes, sea-level oscillation, and specific tectonic events in the orogen. These data provide an understanding of the evolution of the foreland basin and its sub-components including the backbulge, forebulge, and foredeep basins. Moreover, coupled with newly calibrated strontium isotopic curves, this study has allowed for the development of a new model for the Taconic Orogeny that helps to explain differences in the timing and spatial relationships between the southern and northern tectophases.
Advisors/Committee Members: Brett, Dr. Carlton.
Subjects: Geology
Keywords: sequence stratigraphy; ordovician; taconic orogeny; blountian tectophase; chemostratigraphy; strontium isotopes; time restricted facies; mohawkian; trenton group; black river group; chazy group
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18.
CRAVEN, KERI.
THE ORIGIN OF ALKALIC BASALTS FROM HALEAKALA VOLCANO, EAST MAUI, HAWAII.
Degree: MS, Arts and Sciences : Geology, 2003, University of Cincinnati
► Studies of volcanic rocks from Hawaii reveal that the islands were formed…
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▼ Studies of volcanic rocks from Hawaii reveal that the islands were formed through four distinct stages of volcanism. The origin of alkalic rocks produced during the last stage of development is not completely understood. Alkalic basalts can be generated at both high and low pressures. A new method of constraining pressure-temperature conditions of formation was developed, using the compositions of alkalic rocks from Haleakala Volcano. Initial P-T calculations indicated that the rocks formed from low degrees of melting over a range of pressures in the mantle (polybaric melting). Using a trace element modal melting equation and highly incompatible element concentrations, the degree of melting required to produce the Haleakala alkalic magmas was estimated. The results of these calculations indicate that low degrees of melting in the spinel peridotite zone of the mantle under polybaric conditions was required to produce the Haleakala alkalic basalts.
Advisors/Committee Members: Kilinc, Dr. Attila.
Subjects: Geology
Keywords: mantle peridotite melting; Magma Generation; alkali basalt; trace and rare earth elements
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19.
Dame, Elizabeth A.
Assessing the effects of predation and habitat complexity on the recovery of the long-spined sea urchin, Diadema antillarum, in Curaçao.
Degree: PhD, Arts and Sciences : Geology, 2008, University of Cincinnati
► Over the past several decades, decreased herbivory due to the mass mortality…
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▼ Over the past several decades, decreased herbivory due to the mass mortality of a keystone grazer, the long-spined sea urchin, Diadema antillarum, has contributed significantly to the proliferation of noncoralline macroalgae on western Atlantic coral reefs, including Curaçao in the Netherlands Antilles. Nearly 25 years after the dieoff, densities of D. antillarum remain below pre-mortality levels. The recovery of D. antillarum may be slowed due to the decreasing structural complexity of reefs, as these urchins need adequate shelter to avoid predators. I tested the hypothesis that added artificial structure reduces predation and thereby increases the persistence of translocated urchins. Translocated urchins exhibited greater persistence in plots with artificial structure. The hypothesis that translocated D. antillarum exhibit differential persistence with regard to distinctive structures was also tested. Individuals exhibited greater persistence in structures that were more enclosed and better mimicked natural reef crevices. Considering that D. antillarum densities are presently higher closer to shore than on the reefs of Curaçao, I tested the hypothesis that predation pressure on D. antillarum is greater on the deeper forereef than on the shallow reef crest by surveying the densities and biomasses of predators, and the densities of D. antillarum on six reefs. Additionally, video observations on caged urchins were used to assess relative predation pressure between the two depths. Data from surveys and video experiments indicate densities of predators are not greater on the forereef when compared to the reef crest. There was no significant correlation between D. antillarum densities and predator densities, or between D. antillarum densities and predator biomass on the reef crest or the forereef. I also surveyed these six reefs to examine the relationship between D. antillarum densities, topographic complexity, and reef condition. Diadema antillarum densities were not linked with topographic complexity on the reef crest; however, a positive correlation existed between urchin densities and habitat complexity on the forereef. Habitat complexity is likely limiting recovery of this urchin in greater depths. This study demonstrates the importance of conducting restoration studies that integrate an experimental and ecological approach to gain a better understanding of factors limiting recovery of D. antillarum.
Advisors/Committee Members: Meyer, David L.
Subjects: Biology; Ecology; Environmental science; Geology
Keywords: coral reefs; recovery; Diadema antillarum; translocation; predation; habitat complexity
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20.
Deline, Bradley.
The Effects of Scale, Community Structure, and Environment on Ordovician through Early Silurian Laurentian Crinoid Disparity.
Degree: PhD, Arts and Sciences : Geology, 2009, University of Cincinnati
► The quantification of morphological disparity is an important tool in the study…
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▼ The quantification of morphological disparity is an important tool in the study of macroevolution. Estimating disparity is difficult and is therefore relatively understudied in relation to taxonomic diversity. The current study aims to reexamine and explore the disparity of Early Paleozoic crinoids across geographic and taxonomic scales. Disparity is calculated based on the coding of discrete morphological characters. Regional crinoid disparity was examined using greater stratigraphic resolution and taxonomic coverage in order to test the patterns and interpretation of previous studies. At the local level (i.e. biofacies) the effects of different communities on measures of disparity as well as the meaning of rarity in regard to morphological uniqueness was examined. In agreement with previous studies, Ordovician through Early Silurian crinoid disparity rapidly expanded than stabilized during the Ordovician. However, the current study shows a major rise in disparity during the Silurian recovery following the Ordovician Mass Extinction. This rise is mostly because of the proliferation of the myelodactylids that were well suited to the soft substrate environments that expanded late in the Ordovician. Examination of both the Late Ordovician and Permian extinctions indicate that there is no evidence of an increased rigidness of morphology during recoveries and if genetic canalization played a large role in crinoid morphologic history, it likely occurred during the Early Ordovician. Biofacies level disparity shows a very different pattern from the regional patterns. On average biofacies have equitable disparity through time and individual biofacies do not show strong differences in disparity with regard to environment, time, or geography. Contrary to previous studies the choice of taxonomic level can affect the results in two ways. First, the number of species per genera can change through time such that the disparity of time bins with a higher ratio will be underestimated. Secondly, combining aberrant species into a single genus can drastically reduce disparity values as is seen in myelodactylids in the Early Silurian. Local disparity was also examined in regard to community structure. Even though many disparity metrics are not sample-size dependant biases can result from rare taxa being outliers or merely segregated in morphospace from common taxa. In Early Paleozoic crinoids rare species do not contribute more to local disparity than common species, however, in some biofacies rare crinoids occupy separate areas of morphospace. Weighting local disparity by abundance is a less biased metric that includes elements of morphology, evenness, and subgroup occupation. Localities that have a low weighted to unweighted disparity ratio often are strongly structured following aerosol filtration theory. Localities that have equitable values for the two metrics often are at intermediate depths, occur early in crinoid history, or are environmentally or ecologically disturbed. Examining the ratio of these metrics for crinoid biofacies through time it appears that structured community based on aerosol filtration theory appeared no later than the Late Middle Ordovician.
Advisors/Committee Members: Brett, Carlton.
Subjects: Geology
Keywords: Crinoid; Cupulocrinus
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21.
DELINE, BRADLEY L.
INTER- AND INTRASPECIFIC MORPHOLOGICAL VARIATION OF CRINOID COLUMNALS IN RELATION TO WATER DEPTH IN THE TYPE CINCINNATIAN (UPPER ORDOVICIAN).
Degree: MS, Arts and Sciences : Geology, 2006, University of Cincinnati
► Crinoid columnals are a major constituent in the Upper Ordovician fossil assemblage…
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▼ Crinoid columnals are a major constituent in the Upper Ordovician fossil assemblage of the Cincinnati Arch Region. Several species of Cincinnatian crinoids are identifiable based on columnal morphology alone. Disarticulated columnals of two crinoids were measured throughout a 68-meter section of the Kope and lower Fairview Formations to examine the relationship between columnal morphology and sea level fluctuations. The columnal diameter of two disparid crinoids increased in the upward shallowing sequence. Detrended Correspondence Analysis axis 1 scores computed using columnal measurements of two crinoids correlated significantly with a proxy for depth. Therefore, crinoid columnals may provide a metric for the study of small-scale sea level fluctuation in a depositional sequence. A larger scale study showed similar morphological shifts in five taxa of crinoids, but to differing degrees. The morphologic shifts in the columnals are likely due to differences in nutrient levels and flow regimes between depths.
Advisors/Committee Members: Meyer, Dr. David L.
Subjects: Paleontology
Keywords: Crinoid, Faunal Gradients, Morphology, Cincinnatian, Ordovician, Cincinnaticrinus
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22.
DEROUIN, SARAH A.
Deglaciation in the Upper Peninsula of Michigan since the Last Glacial Maximum and its relationship to tunnel valleys found in the Lake Superior basin.
Degree: PhD, Arts and Sciences : Geology, 2008, University of Cincinnati
► The Upper Peninsula of Michigan (Upper Peninsula) has undergone several glaciations as…
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▼ The Upper Peninsula of Michigan (Upper Peninsula) has undergone several glaciations as evidenced by the presence of ice-advance moraines, extensive channels, and outwash complexes. In addition, networks of erosive valley-type depressions have been identified in the Lake Superior and Michigan basins bordering the Upper Peninsula. These features are 1-2 km wide, and are up to 200 m deep and are identified as tunnel valleys- subglacial channels found at the margin of ice sheets, thought to evacuate meltwater from the base of the glacier (Halls and West, 1971; Patterson et al., 2003; Regis et al., 2003). These valleys are hypothesized to have yielded multiple, episodic meltwater releases over time, potentially impacting deglaciation processes. To assess this, a eophysical, geomorphological/sedimentological, and chronologic examination was performed,including: 1) determining the presence of tunnel valleys across the Upper Peninsula, 2)identifying geomorphic or sedimentologic signatures of episodic meltwater releases, and 3) establishing radiocarbon chronology of ice retreat. The geophysical survey suggested the discontinuous presence of erosional valley-type features, ranging from 180 to 400 m in relief. The geomorphic investigation supported the existence of tunnel valleys on the Upper Peninsula, identifying landformsassociated with the valleys (i.e.- kettled fan outwash complexes, discontinuous eskers and channels). Episodic meltwater releases are likely, based on multiple, large-scale outwash fans, lobate kettled plains, and erosional bars. Lastly, deglaciation is thought to be time transgressive as the LIS retreated northward, based on radiocarbon dating of kettle lake organics. The LIS is suggested to have been in the Lake Superior basin by 8500 14C yr BP. These examinations indicate deglaciation in the Upper Peninsula was shaped by the presence of tunnel valleys found in the Lake Superior basin.
Advisors/Committee Members: Lowell, Thomas.
Subjects: Geology
Keywords: glacial geology, geomorphology, tunnel channels, radiocarbon
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23.
Dortch, Jason M.
Defining the Timing of Glaciation in the Central Alaska Range.
Degree: MS, Arts and Sciences : Geology, 2007, University of Cincinnati
► A succession of moraines and terraces in the Nenana River valley, Reindeer…
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▼ A succession of moraines and terraces in the Nenana River valley, Reindeer Hills, and the Monahan Flat in the central Alaska Range were dated using Terrestrial Cosmogenic Nuclides (TCN) and optically stimulated luminescence (OSL). Moraines date at >125 ka (Lignite Creek glacial stage), ~60 ka (Healy glacial stage), 22-30 ka (Riley Creek 1 glacial stage), ~22 ka (Riley Creek 2 glacial stage), and ~19 ka (Carlo glacial stage). These are minimum ages of deglaciation. Comparative examination of boulders shows that the position of boulders and condition/type of landforms are more influential of TCN ages than the condition of boulders. TCN ages on boulders from drumlins are more tightly clustered than morainal boulders. No correlation of boulder condition and accuracy of TCN ages was found.
Advisors/Committee Members: Owen, Lewis A.
Subjects: Geology
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24.
Dortch, Jason Michael.
Rates of landscape development in the Transhimalaya of northern India: a framework for testing the links among climate, erosion, and tectonics.
Degree: PhD, Arts and Sciences : Geology, 2010, University of Cincinnati
► Models linking Earth’s surficial (exogenic) processes and internal processes (endogenetic) have been…
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▼ Models linking Earth’s surficial (exogenic) processes and internal processes (endogenetic) have been evolved recently, specifically involving the role of glaciation and fluvial incision in unloading rock mass and inducing surface uplift, and the influence of glacial, fluvial, and mass wasting systems in limiting and/or creating topography. However, these models are poorly defined due to a lack of quantified studies of the rates and magnitudes of geomorphic processes that control erosion and landscape development. Furthermore, the regional variability of erosive processes and the role of high magnitude-low frequency processes in landscape development are poorly defined. A key area of the Himalaya-Tibetan orogen, northern Ladakh was therefore examined using field mapping, satellite remote sensing and terrestrial cosmogenic nuclide (TCN) methods to quantify the relative role of these processes and to provide a framework to test the newly developing geologic models. The new data allows linkages between climatic change, long-term temporal variation in the rates of geomorphic processes, and catastrophic events are assessed. Study of glaciation shows in Ladakh shows showed that glaciations was approximately twice as extensive on the northern side of the Ladakh Range during the same glaciation, which would implies that that erosion should be greater on the northern slopes of the range. To test this assumption, TCN basin wide erosion methods that integrate long-term erosion were undertaken and show that catchments on the southern side of the range erode at ~0.025 mm/yr while three catchments on the northern side erode at ~0.050 m mm/yr. This suggests that erosion rates are dominantly controlled by glaciation. Seventeen strath terraces in the Himalaya and Transhimalaya were dated using TCN methods to test the temporal variations in the rates of incision. These data were combined with previous studies that show that Holocene fluvial incision rates range from ~0.02 mm/yr to ~26 mm/yr, while Pleistocene fluvial incision rates ≤ 5 mm/yr. This argues that fluvial incision is more important than glacial erosion in shaping landscapes in Ladakh. Examination and dating of large landslides and catastrophic flood deposits show that there are strong temporal controls on these events, coincident with times of increase rainfall when the monsoon was enhanced. Climatic records show that the Holocene (0-10 ka) is a generally wet period and that 10-35 ka is generally more arid. Three of the four large landslides occurred during enhanced monsoon phase-2 (~8 ka). This new data, combined with a regional summary of all large and giant landslides dated in the Himalayan-Tibetan Orogen (n=12) shows a strong correlation between sliding occurrence and intensified monsoon precipitation. These data show that temporal variations in incision rates and landslide occurance are strongly coupled with significant fluctuations in precipitation due to intensified monsoons throughout the Quaternary.
Advisors/Committee Members: Owen, Lewis.
Subjects: Geology
Keywords: cosmogenic; geochronology; ladakh; himalaya; glaciation; strath
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25.
Esker, Donald Anton.
An Analysis of the Morrison Formation’s Terrestrial Faunal Diversity Across Disparate Environments of Deposition, Including the Aaron Scott Site Dinosaur Quarry in Central Utah.
Degree: MS, Arts and Sciences : Geology, 2009, University of Cincinnati
► The Aaron Scott Site dinosaur quarry (Quarry) in the Morrison Formation of…
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▼ The Aaron Scott Site dinosaur quarry (Quarry) in the Morrison Formation of Utah offers a unique view of Late Jurassic patterns of terrestrial diversity. The Quarry represents a rare perennial lacustrine environment of deposition, preserving a diverse population of large and small vertebrate and invertebrate fauna. The null hypotheses state that patterns of diversity at the Quarry do not differ significantly from those found at ephemeral lacustrine sites elsewhere in the Morrison, and an even spread of terrestrial diversity across the Late Jurassic Morrison Basin. While evidence has revealed a similarity between the Quarry and ephemeral lacustrine sites, multivariate analysis reveals distinct patterns in terrestrial diversity of the Morrison Formation, most prominently, a division between wetland and dry land taxa, and between ornithischian and sauropod dominated environments. Unusual patterns found among several taxa pairs hint that two (or more) Morrison genera may be sexual dimorphs or organisms at different stages in their ontogeny. While the Quarry itself may not be wholly unique, the Morrison was far more complex than traditionally portrayed.
Advisors/Committee Members: Storrs, Glenn.
Subjects: Earth; Freshwater ecology; Geology; Paleoecology; Paleontology
Keywords: vertebrate paleontology; multivariate analysis; Morrison Formation; Jurassic; dinosaurs; Paleobiology Database; paleoecology; Aaron Scott Site; lacustrine; palustrine; sphenodont; sexual dimorphism; geology; Utah; lagerstatten
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26.
FERGUSON, CHAD ALLEN.
SPATIAL AND TEMPORAL FIDELITY OF SUBFOSSIL MOLLUSCAN ASSEMBLAGES IN A MODERN, SHALLOW MARINE CARBONATE SETTING.
Degree: MS, Arts and Sciences : Geology, 2003, University of Cincinnati
► To better understand the processes that produce time-averaged fossil assemblages, paleontologists have…
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▼ To better understand the processes that produce time-averaged fossil assemblages, paleontologists have long investigated the formation of subfossil assemblages on modern seafloors. Generally, it has been demonstrated that these assemblages faithfully reflect the living assemblages and benthic environments from which they were derived. Nevertheless, they may typically contain skeletal material that is hundreds to thousands of years old, and few researchers have considered how subfossil assemblages change over time in response to environmental transitions that alter life assemblages. In this investigation, I evaluate the degree of temporal stability among subfossil molluscan assemblages over a span of some two decades in Smuggler’s Cove, St. Croix, US Virgin Islands. A transect sampled initially by Miller in 1979-1980 was reestablished approximately and resampled during 2002. The transect paralleled a gradient of decreasing seagrass cover and increasing bioturbation by the decapod crustacean Callianassa. Subfossil molluscan samples and benthic vegetation counts were taken at 30 m lateral intervals for direct comparison with data from Miller’s study. Results demonstrate that, after 22 years, species richness and composition of subfossil molluscan communities continue to reflect the fundamental environmental gradient, characterized by a transition from herbivorous gastropods and lucinid bivalves in seagrass beds to actively burrowing bivalves and predatory gastropods in bioturbated zones containing less seagrass. However, the abundance of key taxa changed significantly along the transect during the intervening period; these differences can be recognized in both the subfossil and living assemblages. Most notably, there was a significant decline throughout the study area of the previously ubiquitous grazing gastropod, Cerithium litteratum, and an increase in the abundance of another grazing gastropod, Tricolia affinis. These results indicate that subfossil assemblages are highly dynamic and continue to incorporate changes in the life assemblage until the moment of isolation from surficial sedimentary processes. The fidelity to life assemblages of time-averaged subfossil assemblages clearly depends on the ability of the subfossil assemblages to keep pace with changes in the composition of the live fauna.
Advisors/Committee Members: Miller, Dr. Arnold I.
Subjects: Paleontology; Paleoecology
Keywords: subfossil assemblage; seagrass; Smuggler's Cove; cerithium; tricolia
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27.
Ferguson, Chad Allen.
Environmental Change and Molluscan Death Assemblages: An Assessment of Ecological History Along a Carbonate Bank in Florida Bay.
Degree: PhD, Arts and Sciences : Geology, 2009, University of Cincinnati
► Marine death assemblages typically reflect the ecological and environmental signatures of the…
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▼ Marine death assemblages typically reflect the ecological and environmental signatures of the settings in which they are deposited. Comparatively little is known, however, about the effects of environmental change on death assemblages or with what acuity past changes might be preserved, by proxy, in sedimentary deposits. This study assesses the response of present-day molluscan death assemblages, both among surface sediments and stratigraphically, to an instance of anthropogenic environmental change along a carbonate bank. Additionally, I investigate whether body size changes can be recognized among death assemblages as a component of a broader response to changing environmental conditions.Environmental perturbation along Cross Bank, in Florida Bay, resulted from an experiment, during the early-mid 1980’s, where local benthic environments were subjected to nutrient enrichment. Elevated nutrient levels drove a transition between morphologically and sedimentologically distinct seagrass species, from Thalassia testudinum, the regionally dominant seagrass species, to Halodule wrightii. Altered localities from this previous investigation, occurring at regular intervals along the crest of Cross Bank, were used to form an experimental transect to investigate changes in molluscan death assemblages following environmental changes along the bank. A second, control transect was established at sites approximately 50 m N-NE of altered localities to capture the signature unaltered death assemblages. Data considered here were derived from two distinct sampling protocols: two shallow (~15 cm) push cores and a single (82 cm average length) piston core, later subsampled at 2 cm increments, collected at each of twelve study sites to assess the present state of molluscan death assemblages and their ability to record historical environmental change. Results demonstrate that molluscan death assemblages can effectively retain, by proxy, evidence of environmental change and signals may persist in the sedimentary record on decadal time scales. A transition from Thalassia to Halodule at altered sites appears to be preserved stratigraphically among death assemblages as an envelope defined by assemblage-level properties and compositional variations, rather than a distinct turnover event. Specimen abundance, taxonomic richness, and calculated evenness display strong declines with depth below the sediment-water interface across study localities, likely a taphonomic modification of assemblages through compaction. Findings also indicate that death assemblages are capable of capturing within-taxon changes in mean body size and distribution over ecological time scales, which may elucidate underlying paleoecological shifts during an environmental change.
Advisors/Committee Members: Miller, Arnold.
Subjects: Biology; Earth; Ecology; Environmental science; Geology; Paleoecology; Paleontology
Keywords: molluscan death assemblages; subfossil; carbonate bank; body size; sea shell; mollusk; coastal monitoring; seagrass bed; environmental change; anthropogenic; nutrient enrichment; coastal environment; Thalassia; Halodule; Cerithium; Florida Bay
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28.
Fields, Kris.
Wellhead Protection Area Delineation for a Small Community in a Buried Valley Setting Near Waynesville, Ohio.
Degree: MS, Arts and Sciences : Geology, 2000, University of Cincinnati
► Dakin Estates, a small community located approximately 1.5 miles south of Waynesville,…
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▼ Dakin Estates, a small community located approximately 1.5 miles south of Waynesville, Ohio, obtains its drinking water from the Little Miami River (LMR) buried valley aquifer. The aquifer is composed of permeable sands and gravels overlain by a laterally continuous, clay-rich confining unit. While present water demand is easily satisfied by the aquifer, its inherent potential for contamination poses a serious threat to the community. Recognizing the detrimental effects of water pollution, the owner of Dakin Estates has elected to implement a Wellhead Protection (WHP) Program. The WHP program is designed to protect the drinking water of communities dependent upon groundwater. Hydrogeologic data was obtained from maps, well logs, previous and similar studies, outcrops, pump tests, and monitoring of groundwater and surface water levels. These data were used to formulate a conceptual model that was tested with a numerical flow model using the United States Geological Survey's (USGS) MODFLOW, a modular, finite-difference, groundwater flow model. Because LMR exerts a strong influence on groundwater levels in the vicinity of Dakin Estates, model calibration was based on fluctuation of groundwater levels corresponding to change in river stage. Water chemistry analyses were performed using the USGS PHREEQC aqueous geochemical mixing model. The geochemical results provide an independent assessment of the validity of the conceptual and numerical models. MODPATH, an advective transport particle-tracking model, was used to delineate the area contributing water to the pumping well for a specified time period. The results of this study indicate the Wellhead Protection Area (WHPA) extends upgradient, roughly paralleling the strike of the valley, without encountering significant flow boundaries. Results of the geochemical analyses suggest significant interaction between groundwater and surface waters is occurring, likely upstream from the WHPA. The water obtained by Dakin Estates is a mixture of underflow from upstream, infiltration of surface water, and aerial recharge. Predictive simulations indicate the aquifer is capable of yielding projected increase of future demand.
Advisors/Committee Members: Nash, David.
Keywords: groundwater; LMR; aquifer; WHP; MW-1; MHC; recharge
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29.
Flege, Adam Eric.
SULFATE REDUCTION IN FIVE CONSTRUCTED WETLANDS RECEIVING ACID MINE DRAINAGE.
Degree: MS, Arts and Sciences : Geology, 2001, University of Cincinnati
► Constructed wetlands have been shown to be effective in treating various types…
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▼ Constructed wetlands have been shown to be effective in treating various types of wastewater. One type, Acid Mine Drainage (AMD), is characterized by high acidity, heavy metals, and sulfate. Five Constructed Wetlands, Friar Tuck, Tecumseh, and Midwestern in southwestern Indiana, and Simco and Wills Creek wetland in Ohio, were studied to determine their treatment efficiencies for sulfate and metal removal. Sulfate Reduction by microorganisms in constructed wetlands can remove sulfate and dissolved metals, and can generate alkalinity. Approximately 100 water samples and 50 soil samples were taken during the winter and summer seasons at the five wetlands and analyzed for sulfate and metal concentrations, sulfur isotope values, pH, Eh, and conductivity. Resulting data indicates that sulfate reduction is occurring at all five wetlands, but varies in degrees of treatment effectiveness. The Friar Tuck wetland shows minimal evidence of sulfate reduction, with dilution being the main remediation mechanism. A small volume of AMD is being overwhelmed by numerous freshwater inputs resulting in a significant improvement in water chemistry due to this dilution. The Tecumseh wetland shows little change in influent/effluent sulfate and sulfide values suggesting that treatment of the influent wastewater by sulfate reduction was ineffective for both sampling seasons. The Midwestern wetland for the summer season shows a significant increase in water sample δ 34 S, from -5.03 permil to +0.27 permil with a corresponding drop in sulfate concentrations from 1740 ppm to 831 ppm, demonstrating successful sulfate reduction and wastewater treatment. However, the winter season sampling showed no change in δ 34 S, indicating only minor sulfate reduction, but sulfate concentrations still fell from 1740 ppm to 831 ppm, indicating an additional sulfate removal process. The Wills Creek wetland shows little change in influent/effluent sulfate concentrations and sulfur isotope values suggesting that sulfate reduction is inactive for both sampling seasons. The Simco wetland was flooded due to beaver constructed damns during our winter sampling and accurate data were not obtained. Summer water sample data show a significant increase in δ 34 S, from -3.58 at the influent to +6.26 at the effluent and a corresponding decrease in sulfate concentrations from 640 ppm to 290 ppm, demonstrating successful sulfate reduction trends.
Advisors/Committee Members: Maynard, Barry.
Subjects: Geology
Keywords: SULFATE REDUCTION; SULFUR ISOTOPE; CONSTRUCTED WETLANDS; ACID MINE DRAINAGE; ANOXIC LIMESTONE DRAINS
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30.
Fuentes, Stephanie Renee.
Faunal Distribution Across the Ordovician-Silurian Boundary in Ohio and Ontario.
Degree: MS, Arts and Sciences : Geology, 2003, University of Cincinnati
► The Late Ordovician mass extinction is one of the most extensive faunal…
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▼ The Late Ordovician mass extinction is one of the most extensive faunal events in earth history. However, there have been few local analyses on the faunal turnover at this boundary. In addition, it has been suggested that this boundary does not exhibit marked ecologic change. The purpose of this study is to compare faunal distribution from the Upper Ordovician to the Lower Silurian in terms of faunal turnover, ecologic structure, and genus richness. Samples were collected from strata that represent comparable depositional environments, including the Drakes and Brassfield Formations of Ohio, and the Georgian Bay and Cabot Head Formations of Ontario. Multivariate techniques suggest a change in the composition and abundance ratios of taxa across the boundary in the study region. There is no evidence of significant ecologic restructuring across the Ordovician-Silurian boundary and the distribution of some rarefied samples suggests slightly elevated richness in the Silurian.
Advisors/Committee Members: Brett, Dr. Carlton.
Subjects: Geology; Paleontology
Keywords: late Ordovician mass extinction; Ordovician-Silurian boundary; multivariate analysis
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