Physical Sciences and Mathematics Commons^™

Authigenic Minerals In Volcaniclastics From An Eastern African Paleolake: A Proxy For Paleoenvironment, Kaitlyn Truss

Theses and Dissertations

Olduvai Gorge exposes the stratigraphy of Paleolake Olduvai, an often saline-alkaline rift lake that records volcanism from the Ngorongoro Volcanic Highlands. In 2014, cores retrieved from the study area revealed new stratigraphy, including the lacustrine Naibor Soit Formation (Fm) and the volcaniclastic Ngorongoro Fm. In the Ngorongoro Fm part of the cores, mineralogy and geochemistry are the best paleoenvironmental proxies, since under saline-alkaline conditions, volcanic glass alters into specific authigenic minerals (e.g., zeolite, feldspar). This study employs X-Ray Diffraction, X-Ray Fluorescence, and Scanning Electron Microscopy to analyze authigenic mineralogy and geochemistry. The lower Ngorongoro Fm experienced the most alteration, with …

In-Depth Geochemical Analysis Of Turbidite-Associated Shales Of The Pindos Basin, Greece, Jonathon Michael Sevy

Theses and Dissertations

Detailed geochemical analysis of the turbidite-associated shales of the Cretaceous Katafito Formation, Greece, reveals important details regarding the paleoenvironment, paleoproductivity, and regional tectonics of the Pindos Basin. The Katafito Formation was deposited along an active margin at the early onset of closure of the Tethys Sea in the Pindos sub-basin. While careful studies of the coarse clastic component of turbidites are common, this study consisted of a detailed geochemical characterization of the fine-grained portions, which helped reveal paleoenvironmental information about the basin. This study combined organic and inorganic geochemistry utilizing elemental, mineralogical, and organic chemical signatures from fine-grained turbidite-associated sediments …

A Faunal Composition Of The Late Cretaceous Blue Springs Site In Northeastern Mississippi And Evidence For Potential Paleoenvironmental Differences Between Beds, Ginger Trochesset

Honors Theses

The Maastrichtian-age Blue Springs locality of the Coon Creek Member of the Ripley Formation is known for abundant, well-preserved marine fossils, including many genera of microfossils, bivalves, gastropods, decapods, cephalopods, actinopterygians, and other vertebrate organisms. This research contributes to the understanding of the paleontology of the site, as well as the changing paleoenvironmental conditions of the beds throughout deposition.

This project analyzed bulk material collected in 2021 from three fossiliferous beds at Blue Springs: the Lower Corbula Bed (Bed C), the Pebble Bed (Bed G), and the Exogyra-Pycnodonte Bed (Bed J). Unconsolidated material from Beds C and J was processed …

Stable Carbon And Oxygen Isotopes Of Early Silurian Pentameride Brachiopods From Québec, Ontario, And Nunavut, And Paleoenvironmental Implications, Jordan N. Siewnarine

Electronic Thesis and Dissertation Repository

Analysis of low-Mg calcite brachiopod shells for δ¹⁸O and δ¹³C signatures provide quantitative independent geochemical data for paleoenvironmental interpretations. We analyzed 59 brachiopod shells from lower Silurian carbonate rocks of Anticosti Island, the Hudson Bay Lowlands and Niagara regions for spaciotemporal isotopic trends for the early Silurian. Screening tests using scanning electron microscopy, cathodoluminescence and trace element analysis demonstrate exceptional preservation, suggesting retention of primary isotopic values.

δ¹³C and δ¹⁸O values of shells range from 0.2‰ to 2.9‰ and -6.9‰ to -4.3‰ (VPDB), respectively. Temporally, increases in δ¹³C and δ …

New Black Carbon Isotopes From The Eastern Tethys And Earth System Modeling During The Petm, Maurizia De Palma

Theses, Dissertations and Culminating Projects

The Paleocene-Eocene Thermal Maximum (PETM; ca. 56Ma) is a time when global temperatures greatly increased due to rapid carbon emissions. The event is marked by a negative carbon isotope excursion (CIE) that is observed in both marine and terrestrial records. However, the amount, rate, and source of the emitted carbon remains highly debated. This study investigates the response of the eastern Tethys, an understudied subtropical shallow marine environment, and assesses the climatic impacts during the PETM. An Earth system model of intermediate complexity (cGENIE) ran six “double-inversion” experiments with δ¹¹B and δ¹³C_carb forced onto the …

Community Structure Analysis Of Mammals Found At The Gray Fossil Site, Tn, Sarah Clark

Electronic Theses and Dissertations

The early Pliocene Gray Fossil Site (GFS) is a biodiverse site with a unique faunal assemblage that represents one of few sites of its age in eastern North America. A community structure analysis of the mammals at GFS was done to characterize species and better understand the paleoenvironment. Data and was gathered from twenty modern communities and five late Neogene sites to compare with GFS. Species from these 26 sites were categorized by body size, locomotor mode, cheek tooth crown height, and diet to characterize niches occupied. Descriptive statistics contrasted proportions of species within categories across communities. Discriminant function analyses …

Experimental Insights Into The Origin Of Microcrystalline Calcites, Mohammed Hashim

Dissertations

A significant proportion of modern marine calcium carbonate sediments is dominated by metastable aragonite and high Mg calcite that either dissolves or stabilizes to low-Mg-calcite (calcite) or dolomite during diagenesis. Sediment dissolution and stabilization have implications for the CaCO3 budget in the ocean and carbon burial rates. Yet, the diagenetic conditions that promote each process and their relative importance are poorly understood. Further, stabilization most commonly produces calcite microcrystals that exhibit various textures and host micropores. Despite their ubiquity in the rock record, the controls on microcrystal textures remain unclear. Here, laboratory experiments were used to investigate aragonite-to-calcite stabilization as …

Archaeology And Seasonality Of Stock Island (8mo2), A Glades-Tradition Village On Key West, Ryan M. Harke

USF Tampa Graduate Theses and Dissertations

Later Glades-period cultures (ca. 500–1760 CE) of south Florida and the Florida Keys are understudied and thus poorly understood, especially those that pre-date the arrival of Spaniards to the New World. Recent archaeological models of their sociopolitical organization suggest that by the Glades I-II transition (750/800 CE), south Florida peoples were organized into what appear to be regional population centers (e.g., Pineland and Mound Key, Granada, Turner River) and smaller hinterland towns in the Everglades (e.g., Cane Patch, Bear Lake) and the Florida Keys (e.g., Stock Island, Clupper Site). Smaller towns are hypothesized to be sedentary, heterarchically-organized, simple chiefdoms from …

Fire-Vegetation-Climate Interactions Across The Holocene On The U.S. Southeastern Coastal Plain, Mathew S. Boehm

Doctoral Dissertations

This dissertation research examined multiple proxy indicators in sediment cores from one lake and one wetland to reconstruct long-term relationships between fire, vegetation, and climate in the southeastern U.S.

At Lake Balboa (30.6992 N, 83.2031 W; 48 m elevation), a sinkhole pond located in southern Georgia, Bølling-Allerød conditions were sufficiently wet to maintain a shallow wetland at the site. Evidence for fire was minimal. Between 12,600 and 9200 cal yr BP, water availability declined, leading to a potential hiatus in sedimentation. During the early Holocene moisture availability increased, leading to greater primary productivity within and outside the lake, triggering an …

Paleoenvironment Reconstruction Of The Eocene Southeastern Tethys Using Geochemistry Of Sedimentary Rocks, Liliana CalderóN Convers

Theses, Dissertations and Culminating Projects

The Early Eocene hyperthermals are a series of transient global warming events that occurred between 54.09 and 52.63 Ma, and are considered as ancient analogues for future climate change. These hyperthermal events are well studied in the deep sea sites, but have not been investigated in the eastern Tethys Ocean. Here, we report new major and trace element geochemistry and stable carbon isotope data of the Early Eocene strata deposited in a shallow marine foreland basin prior to the main stage of India-Asian continent collision at Qumiba section in the Tingri County, southern Tibet. These geochemical data are used to …

Vegetation Prior To And During Onset Of East Antarctic Glaciation: High Resolution Palynological Insights From Sabrina Coast, East Antarctica, Meghan L. Duffy

LSU Master's Theses

The Aurora Subglacial Basin (ASB) contains an estimated 3.5 m of global sea-level equivalent ice volume and is primarily drained by the Totten Glacier system, which terminates at the Sabrina Coast, East Antarctica. Thinning and retreating of the Totten Glacier indicate that this region is highly susceptible to oceanographic and atmospheric warming. The paleoclimate reconstruction of these changes, conducted in the context of this MS thesis, will improve understanding of East Antarctic Ice Sheet (EAIS) dynamics in this sensitive system. A recent study used seismic and sediment core data to document a dynamic early evolution of the EAIS in the …

Photometric Investigations Of Weathering Rinds And Coatings With Implications For Mars, Kathleen Hoza

WWU Graduate School Collection

Reflectance spectroscopy is a major technique for characterizing the composition of planetary surfaces, and has led to many key findings in planetary geology. In laboratory measurements, reflectance spectrometers typically acquire data using a standard, fixed viewing geometry. Measurements from spacecraft, however, may be acquired at a wide range of viewing geometries, depending on the orientation of the instrument relative to the target surface and the Sun. For many materials, the impact of viewing geometry on reflectance is minor; however, some materials’ spectral signatures can be influenced by these photometric effects. In particular, spectra of weathering rinds and rock coatings are …

Mainland Southeast Asia In The Longue Durée: A Zooarchaeological Test Of The "Broad Spectrum Revolution" In Northern Thailand, Cyler Norman Conrad

Anthropology ETDs

In northern Thailand, previous zooarchaeological research suggests that hunter-gatherers consumed a broad diversity of animal resources during the Pleistocene-Holocene transition and afterwards (Gorman 1971a). This is a pattern characteristic of Kent Flannery’s (1969) “broad spectrum revolution” hypothesis. Based primarily on presence and absence evidence, faunal assemblages in northern Thailand typically include species of mammals, reptiles, birds, fish and shellfish, suggesting that prehistoric foragers consumed a wide range of taxa within this mainland Southeast Asian tropical environment. Although zooarchaeological analyses commonly identify this pattern within prehistoric cave and rockshelter sites, past investigations have 1) not attempted to formally test Flannery’s hypothesis, …

Stratigraphic Reconstruction Of A Late Pleistocene Bald Cypress Forest Discovered On The Northern Gulf Of Mexico Continental Shelf, Suyapa Michell Gonzalez Rodriguez

LSU Master's Theses

A previously buried bald cypress forest (Taxodium distichum) was discovered on the continental shelf, offshore of Orange Beach, Alabama, USA, in ~20 m water depth. The forest was exhumed by Hurricane Ivan in 2004, and is now exposed as stumps in life position in a trough located in the northern Gulf of Mexico continental shelf seafloor. We are investigating the local stratigraphy, paleo-landscape, and mode of forest preservation of this unique site. In August 2015 and July 2016, submersible vibracores (18 in total) were collected. Core analysis included: bulk density and imaging via Geotek multi sensor core logger, …

Paleogene-Early Neogene Palynomorphs From The Eastern Equatorial Atlantic And Southeastern Florida, Usa: Biostratigraphy And Paleoenvironmental Implications, Walaa K. Awad

Doctoral Dissertations

"The transition from greenhouse conditions (Paleocene-Eocene Thermal Maximum, PETM) to icehouse conditions (Early Oligocene) is not well documented in tropical-subtropical regions. One hundred and five samples from Ocean Drilling Program (ODP) Site 959 (Hole 959A and Hole 959D) in the Cote d'Ivoire-Ghana Transform Margin, Alo-1 Well in the northern Niger Delta (Anambra) Basin, Nigeria, and W-17001 in southeastern Florida were studied for their palynological contents. Dinoflagellate cysts were mainly utilized for age refinement and to detect subtle changes in paleoenvironment and paleoclimate during the Paleocene-Early Eocene (ODP Hole 959D and Alo-1 Well) and Late Eocene-Early Miocene (ODP Hole 959A and …

A Method For The Geometric Analysis Of Rugose Coral Growth Ridges As Paleoenvironmental Indicators In The Middle Devonian Hungry Hollow Member Of Widder Formation, Michigan Basin, Andrew Thomson

Electronic Thesis and Dissertation Repository

Skeletons of Devonian rugose corals feature submillimetre-scale growth ridges on their outer surface (epitheca) that record the successive positions of the coral polyp during longitudinal corallite growth. Specimens of rugose corals Eridophyllum and Cystiphylloides from the Hungry Hollow Member of the Middle Devonian Widder Formation were sectioned longitudinally and imaged by SEM, and image processing techniques were applied to extract a line representing the epithecal surface. Local extrema found through peak detection allowed growth ridges to be represented as simplified triangles, so that geometric measurements (area, length) could be related to coral growth and analyzed in reference to possible paleoenvironmental …

An Early Paleogene Palynological Assemblage From The Sabrina Coast, East Antarctica: New Species And Implications For Depositional History, Catherine Davies Smith

USF Tampa Graduate Theses and Dissertations

Palynological analyses of 13 samples from two sediment cores retrieved from the Sabrina Coast, East Antarctica, provide the first information regarding the paleovegetation within the Aurora Subglacial Basin. The assemblages, hereafter referred to as the Sabrina Flora, are dominated by angiosperms, with complexes of Gambierina (G.) rudata and G. edwardsii representing 38–66% of the assemblage and an abundant and diverse Proteaceae component. The Sabrina Flora also includes Battenipollis sectilis, Forcipites sp. and Nothofagidites spp. (mostly belonging to the N. cf. rocaensis-flemingii complex), along with a few fern spores, including Laevigatosporites ovatus, a moderate presence of conifers, and …

Lessons From The Past: Unfolding The Dynamics Among Climate, Balkan Landscapes, And Humans Over The Past Millennium, Charuta J. Kulkarni

Dissertations, Theses, and Capstone Projects

The primary objective of this doctoral dissertation is to reconstruct the environmental history of the Central Balkans (Serbia) over the past millennium utilizing biological proxies (pollen, spores, and charcoal), geochemical signals through X-ray fluorescence (XRF), statistical analyses, and atomic mass spectrometry (AMS) ¹⁴C chronology. This dissertation establishes the first chronological framework for vegetation-landscape changes in Serbia and discusses the role of humans and climate as underlying processes.

Chapter 1 discusses the background and the nature of the research problem followed by the extensive literature review on the topic of the Holocene climate and paleoecology. The state of Holocene paleoecology …

A Palynological Analysis Of Seymour Island And King George Island Off The Antarctic Peninsula: A Dating And Climatic Reconstruction, Caven Madison Kymes

LSU Master's Theses

During the Cretaceous and early Paleocene, Antarctica was covered by lush vegetation. However, Antarctica today is covered with ice and snow leaving less than 1% of the continent inhabited by vegetation. By studying this decline in vegetation and reconstructing past environments, we can gain a better understanding of environmental changes and use this knowledge to predict future changes. In this thesis, I present my results and interpretations of palynological changes across the Antarctic Peninsula during the Late Eocene, Middle Oligocene, and Miocene. The first study discusses a paleoenvironmental reconstruction of the upper La Meseta formation (Late Eocene), Seymour Island, and …

Enhanced Resolution Of The Paleoenvironmental And Diagenetic Features Of The Silurian Brassfield Formation, Lisa Marie Oakley

Browse all Theses and Dissertations

The Brassfield Formation is an early Silurian (Aeronian, Llandoverian) unit of limestone and dolostone with excellent preservation of early reef communities and a diverse invertebrate fauna. A well-preserved outcrop occurs in southwestern Ohio at the Oakes Quarry Park in Fairborn; it contains abundant corals and stromatoporoids that are co-dominant in reef and reef-affected settings. This research provided an enhanced perspective of the Brassfield Formation to better reconstruct its paleoenvironment and better understand its diagenetic features. The depositional and diagenetic features of the Brassfield are described and interpreted using histologic methods and light microscopy. Selected thin sections were treated with carbonate …

Late Permian Paleoenvironmental Factors Expounded Through Analysis Of A Forest-Floor Paleosol Profile, Karoo Basin, South Africa, Cassi Knight

Honors Theses

Beaufort Group paleosols from the Karoo Basin, South Africa, record the paleoenvironmental conditions that existed prior to and after the Permian-Triassic extinction event. Paleosol exposures from Wapadsberg Pass, Eastern Cape Province, represent a well- preserved forest-floor litter overlying an interpreted inceptisol, a condition unique to the basin. Vegetation that colonized this landscape included a canopy of the gymnosperm Glossopteris and an understory of sphenopsids (Phyllotheca and Trizygia). Wapadsberg Pass paleosol sites were sampled for petrographic and geochemical analyses to constrain interpretations of Late Permian paleoenvironmental conditions that existed ~ 70 m below the Permian-Triassic Boundary (PTB). This project focuses on …

Proxy Records Of Paleohurricanes For The Western And Southern Caribbean, Terrence Allen Mccloskey

LSU Doctoral Dissertations

This dissertation evaluates the hypothesis that hurricane activity levels in the North Atlantic during the late Holocene have been driven by latitudinal movements of the North Atlantic circulation system. Multi-millennial sedimentary proxy records, based on the occurrence of overwash clastic layers, provide clear evidence of abruptly alternating periods of hurricane landfall frequency for Nicaragua and Belize. Three Belizean transects exhibit an Active period (hyperactivity) occurring from ~2000-6000 cal yr BP, although dating is inconsistent across the transects. An Active period covering the last 500 years is found at one location. The Nicaraguan record, derived from three transects covering >90 km …

Molluscan Taphonomy As A Proxy For Recognizing Fossil Seagrass Beds, Jill Suzanne Leonard-Pingel

LSU Master's Theses

Seagrass beds, important marine ecosystems both economically and environmentally, have a poor fossil record. As a result, little is known about the geographic distribution of seagrasses over historic and geologic time, or their abundance when unaltered by anthropogenic effects. The purpose of this study is to define a taphonomic signature unique to seagrass beds that can be used as a proxy for identifying the seagrass habitat in the fossil record. In order to develop this proxy, sediment samples from Recent seagrass and non-seagrass environments were collected, and the molluscan bioclasts from these samples were categorically ranked for the following taphonomic …