Multiscale Characterization Of Splays Produced By A Historic, Rain-On-Snow Flood On A Large Braided Stream (Platte River, Central Usa),
2024
University of Nebraska - Lincoln
Multiscale Characterization Of Splays Produced By A Historic, Rain-On-Snow Flood On A Large Braided Stream (Platte River, Central Usa), J. T. Korus, R. M. Joeckel, A. R. Mittelstet, N. Shrestha
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Locating And Assessing Oregon Trail Ruts With Aerial Stereophotographs, Satellite Imagery And Lidar,
2024
University of Nebraska - Lincoln
Locating And Assessing Oregon Trail Ruts With Aerial Stereophotographs, Satellite Imagery And Lidar, P.R. Hanson, Robert Matthew Joeckel, L. M. Howard
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Landscape And Paleoenvironmental Change In Stream Valleys Of The Central Great Plains, North America During Marine Isotope Stage 3 (Ca. 59-27 Ka).,
2024
University of Nebraska - Lincoln
Landscape And Paleoenvironmental Change In Stream Valleys Of The Central Great Plains, North America During Marine Isotope Stage 3 (Ca. 59-27 Ka)., T. Layzell, K. Andrzejewski, R. D. Mandel, P.R. Hanson
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Integrated Geochronological And Chemostratigraphic Study Of Middle Miocene Strata (Ogallala Group) At The Eastern Margin Of The North American Great Plains,
2024
University of Nebraska - Lincoln
Integrated Geochronological And Chemostratigraphic Study Of Middle Miocene Strata (Ogallala Group) At The Eastern Margin Of The North American Great Plains, J. J. Smith, Robert Matthew Joeckel, H. L. Field, G. A. Ludvigson, A. Moller, A. Layzell, S. T. Tucker
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Wetlands In The Nebraska Sandhills,
2024
University of Nebraska - Lincoln
Wetlands In The Nebraska Sandhills, Nawaraj Shrestha
Conservation and Survey Division: Faculty and Staff Publications
Infographic titled “Status of Wetlands in the Nebraska Sandhills” showing multiple maps and charts. The top left features a color-coded wetland persistence map where blue indicates more consistent wetlands and red indicates intermittent wetlands. Additional inset maps show a regional zoom and a U.S. location map highlighting Nebraska. A large scatter plot displays wetland occurrence percentages over time using MODIS (green points) and Sentinel (blue points) satellite data from 2000 to 2024. Text explains how wetlands vary seasonally and annually and how satellite imagery tracks these changes. A smaller bottom chart shows long-term wetland trends, noting increasing occurrence since 1984. …
Thermochronology And Exhumation Dynamics Of Metamorphic Units In The Salmon River Suture Zone,
2024
Missouri State University
Thermochronology And Exhumation Dynamics Of Metamorphic Units In The Salmon River Suture Zone, Jonathan J. Cone
Graduate Theses/Dissertations
The Salmon River suture zone in western Idaho records the Jurassic-Cretaceous (160-90 Ma) accretion of amalgamated volcanic arc terranes onto the North American continent. Rocks exposed at the surface record burial to depths of more than 20 kilometers, with unclear drivers for uplift and exhumation. Two competing hypotheses have been proposed to explain the transport of deep crustal rocks to the surface: (1) delamination of a dense lithospheric root resulted in rapid isostatic uplift of the crust and (2) exhumation of crustal blocks along thrust faults. To test these models, I present temperature-time (T-t) paths for mid-crustal metamorphic rocks constructed …
Geology Of The Bishop 7.5-Minute Quadrangle And Geophysical Modeling To Constrain Syndepositional Deformation Of The Black Warrior Foreland Basin,
2024
Missouri State University
Geology Of The Bishop 7.5-Minute Quadrangle And Geophysical Modeling To Constrain Syndepositional Deformation Of The Black Warrior Foreland Basin, Joseph Edward Lane
Graduate Theses/Dissertations
The Black Warrior basin is a foreland basin formed by the Ouachita–Appalachian orogeny during the late Paleozoic Era. Mississippian strata record the transition from the carbonate platform within the Tuscumbia Limestone to the clastic-rich units within the overlying Pride Mountain Formation and Hartselle Sandstone. The western and southern-most fringes of the Black Warrior basin are covered by thin, post orogenic Cretaceous sediments of the East Gulf Coastal Plain. Geological mapping of the Bishop 7.5-Minute quadrangle revealed subtle deformation in Mississippian strata in the form of gentle folds (
Origin Of Carbonate Mud Mounds In Southwestern Missouri,
2024
Missouri State University
Origin Of Carbonate Mud Mounds In Southwestern Missouri, Jared Mcavoy
Graduate Theses/Dissertations
Small carbonate mud mounds are found in Lower Mississippian strata of southwestern Missouri. These compare favorably with larger mounds, known as Waulsortian mounds, located in the Meuse River valley of southern Belgium. The origin of Waulsortian and similar mounds is unknown, but they commonly are interpreted as accumulations of mud, where the presence of biological organisms responsible for supposed bio-construction remains uncertain. Alternative hypotheses are that these may have been non-cohesive slump or cohesive slide masses. Multiple techniques, including δ13C and δ18O isotopic analyses and unmanned aerial vehicle photography, were used to determine the most feasible working hypothesis. Determining the …
Million-Year Melt-Presence In Mogollon-Datil Volcanic Field Rhyolites: Constraining The Histories Of The Bursum Caldera Resurgent Domes,
2024
Missouri State University
Million-Year Melt-Presence In Mogollon-Datil Volcanic Field Rhyolites: Constraining The Histories Of The Bursum Caldera Resurgent Domes, Ethan Wagner
Graduate Theses/Dissertations
The Mogollon-Datil volcanic field which is located in southwestern New Mexico, is the result of punctuated volcanism and the transition between arc and rift magmatism. The resurgent domes within the 28 Ma Bursum caldera records the transition from rhyolitic to basaltic andesite volcanism that occurred between 27-26 Ma. Using a combination of new zircon U-Pb ages using chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) with zircon U-Pb geochronology and trace element contents by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and whole rock and mineral trace element contents and isotope geochemistry this study investigates the temporal and …
Water Quality Of A Karstic Shallow Aquifer In Greene And Lawrence Counties, Missouri,
2024
Missouri State University
Water Quality Of A Karstic Shallow Aquifer In Greene And Lawrence Counties, Missouri, Claudia Patricia Colmenero Chacon
Graduate Theses/Dissertations
A water quality investigation in the Springfield Plateau aquifer of Greene and Lawrence counties, Missouri, was conducted. Water samples from eleven springs were collected at regular intervals during 2023 to determine major water quality parameters: total dissolved solids (TDS), alkalinity, calcium (Ca), magnesium (Mg), sodium (Na), sulfate (SO4), chloride (Cl) and nitrate-nitrogen (NO3-N), along with per- and poly-fluorinated alkali substances (PFAS) from spring sediments. Nitrate-nitrogen was analyzed because of the importance for environmental health (e.g. to avoid eutrophication). Springs samples were separated by land use into urban and rural samples. In addition, Springfield Plateau water quality …
The Behemoth Of The Last Ice Age: The Evolutionary Saga Of The Columbian Mammoth In North America,
2024
University of Nevada, Las Vegas
The Behemoth Of The Last Ice Age: The Evolutionary Saga Of The Columbian Mammoth In North America, Nathaniel Valentine
Calvert Undergraduate Research Awards
The Columbian’s mammoth evolutionary history can be traced back to the origin of life and its evolutionary lineage can be tracked down by examining select species over geologic time. I conducted a literature review with multiple scientific journals to identify key transitional species that trace their lineage to the Columbian mammoth. Transitional species were selected from the Precambrian and the various periods of the Phanerozoic which exhibited vertebrate-like body structures and behaviors. Evidence suggests that early vertebrate-like animals were present by the Cambrian period. Mammal evolution would continue in the Mesozoic era and radiate in the Cenozoic era. The Columbian …
Groundwater Flow And Water Clarity At Cenotes In The Yucatan Peninsula,
2024
Northern Illinois University
Groundwater Flow And Water Clarity At Cenotes In The Yucatan Peninsula, Laura Rossana Fracica Gonzalez
Graduate Research Theses & Dissertations
Characterizing and predicting groundwater flow in complex karst aquifers poses significant challenges. This study explores the potential application of Acoustic Doppler Current Profiler (ADCP) technology for in-situ groundwater flow measurement within sinkholes (cenotes) in the Yucatan Peninsula, Mexico. Two specific questions are addressed: 1) Can ADCP determine flow within Yucatan Peninsula sinkholes? 2) Are groundwater flow vectors related to water clarity in open cenotes? The geological setting of the Yucatan Platform is characterized by horizontal sedimentary strata with highly permeable limestones and extensive karst features. The research focuses on the Holbox fracture zone, where groundwater flow dynamics remain elusive. The …
10be Dating Of Last Glacial Maximum Moraines And Subsequent Glacial Retreat In Chirripó National Park, Costa Rica,
2024
Dartmouth College
10be Dating Of Last Glacial Maximum Moraines And Subsequent Glacial Retreat In Chirripó National Park, Costa Rica, Caleb Emeka Okpala
Dartmouth College Master’s Theses
During the Last Glacial Maximum (LGM; ~26-19 ka) and Termination 1 (~19-12 ka), the expansion and retreat of glaciers across the Southern and Northern Hemispheres, as well as other paleoclimate proxies, document a complex pattern of global climate change. While the timing and magnitude of LGM cooling and subsequent warming is relatively well constrained in mid- and high-latitude regions across both hemispheres, less information is available about climate changes in the tropics. To provide more information about tropical climate conditions during the LGM and Termination 1, I mapped and dated the extents of past glaciers in two valleys in Chirripó …
A Bayesian Inversion For Emissions And Export Productivity Across The End-Cretaceous Boundary,
2024
Dartmouth College
A Bayesian Inversion For Emissions And Export Productivity Across The End-Cretaceous Boundary, Alexander A. Cox
Dartmouth College Master’s Theses
The end-Cretaceous mass extinction was marked by both the Chicxulub impact and the ongoing emplacement of the Deccan Traps flood basalt province. Both of these events perturbed the environment by the emission of climate-active volatiles, primarily CO2 and SO2. To understand the mechanism of extinction, we must disentangle the timing, duration, and intensity of volcanic and meteoritic environmental forcings. In this thesis, we used a parallel Markov chain Monte Carlo approach to invert for the aforementioned volatile emissions, export productivity, and remineralization from 67 to 65 million years ago using the LOSCAR (Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir) model. The parallel …
Geoelectrical And Hydrochemical Characterization Of Submarine Groundwater Discharge In Florida Bay,
2024
Georgia Southern University
Geoelectrical And Hydrochemical Characterization Of Submarine Groundwater Discharge In Florida Bay, Ifeanyi Emmanuel Eze
College of Graduate Studies: Theses & Dissertations
Florida Bay, situated at the southern tip of Everglades National Park and underlain by the Miami Limestone formation, is an ecosystem of global significance. Over the past century, the bay has faced threats such as droughts, seagrass mortality, and hypersalinity. Despite various studies and management efforts, the dynamics of submarine groundwater discharge (SGD) in the region remain underexplored. Given that SGD plays a significant role in the chemical dynamics of coastal ecosystems, it warrants thorough investigation. This study aims to characterize the spatial and temporal patterns of SGD in Florida Bay by surveying three basins – Rankin, Whipray, and Rabbit …
Diatom Productivity And Nutrient Dynamics In The Ross Sea, Antarctica During Warm Events In The Neogene,
2024
Northern Illinois University
Diatom Productivity And Nutrient Dynamics In The Ross Sea, Antarctica During Warm Events In The Neogene, Marialena Christopoulou
Graduate Research Theses & Dissertations
Increased melting of the Antarctic Ice Sheet (AIS) in recent decades, has had a significant impact on many aspects of the global ocean. Models indicate that by the end of the 21st century atmospheric carbon dioxide (CO2) concentrations may exceed 500 ppm, and the average global temperature will likely warm by more than 2°C. However, data that provide model constraints on potential feedbacks in ice-ocean-atmosphere system are limited by short-timescales (e.g., decadal- to centennial-scale) and incomplete spatial coverage. In particular, little is known about the impacts of future warming and widespread melting of AIS on marine biological productivity, silicate weathering …
Tracing Past Climate Signals Through Multi-Proxy Analysis: Insights From Sedimentary Plant Wax Hydrogen Isotope Data And Long-Term Hydroclimate Records In Estonia,
2024
Northern Illinois University
Tracing Past Climate Signals Through Multi-Proxy Analysis: Insights From Sedimentary Plant Wax Hydrogen Isotope Data And Long-Term Hydroclimate Records In Estonia, Mariliis Eensalu
Graduate Research Theses & Dissertations
In light of the rising global temperatures, there is an increasing need to understand the potential shifts in hydroclimate. Past climate reconstructions offer a glimpse into the possible temperature-moisture dynamics by providing quantitative constraints for hydroclimate variability under different temperature conditions, which can ultimately aid in decreasing the uncertainty in future climate projections. The research presented in this dissertation focuses on utilizing various proxies to reconstruct past hydroclimate conditions, particularly in the Baltic region, with a specific emphasis on Estonia. The second and third chapter aim to improve the understanding of sedimentary plant wax hydrogen isotope (δ2H) data by first …
Temporal Microplastic Concentration Fluctuations Within An Agricultural Creek And Groundwater In Relation To Farming Practices,
2024
Northern Illinois University
Temporal Microplastic Concentration Fluctuations Within An Agricultural Creek And Groundwater In Relation To Farming Practices, Jennifer Abel
Graduate Research Theses & Dissertations
Microplastics (MPs) in agriculture have been well-documented. Agrochemicals, organic fertilizers, and farming equipment all contribute plastic to agricultural soils, groundwater, and surface water and are utilized in different capacities throughout the year. It is unknown how the specific utilization of these products affects the concentration of MPs being input into the environment. Previous research has been primarily related to detection and transport of MPs in soils, groundwater, and surface water. I am unaware of any studies that have taken into consideration farming practices and seasons, and how they may affect any fluctuations in MP concentrations. Water samples (20 L) were …
Paragenesis Of The Austin Chalk Formation In Southwest Texas,
2024
University of Montana
Paragenesis Of The Austin Chalk Formation In Southwest Texas, Mitchell C. Sherry
Graduate Student Theses, Dissertations, & Professional Papers
Presented in this study is a detailed investigation of the paragenesis and diagenetic processes of the Austin Chalk Formation in southwest Texas, utilizing a combination of core-based, petrographic, mineralogic, SEM, and geochemical based analyses. This study is conducted on a single whole rock core from an oil and gas producing well in Webb County, Texas. At this distal shelf location within the Maverick Basin, the Austin Chalk Formation consists of foraminiferal wackestones, siliceous wackestones, foraminiferal mudstones, bentonites, and foraminiferal packstone facies. These facies were deposited below wave base through pelagic, hemipelagic, and gravity driven processes. Petrographic and SEM analyses reveal …
Diagenesis And Quartz Grain Provenance Of The Turner Sandstone,
2024
University of Montana, Missoula
Diagenesis And Quartz Grain Provenance Of The Turner Sandstone, Carson Lee Broaddus
Graduate Student Theses, Dissertations, & Professional Papers
Provenance analysis of sedimentary rocks is an essential tool for basin analysis and paleogeographic reconstructions. Numerous tools and analytical methods have been developed over the years to investigate the source of detrital constituents in sedimentary rocks. The Late Cretaceous (Turonian) Turner Sandstone in the eastern Powder River Basin (PRB), WY, and the time equivalent Frontier Formation in the western PRB are commonly described as the remnants of a marginal marine depositional system. However, contradictory evidence exists about the source of those deposits. Here, I present results from a comprehensive scanning electron microscope panchromatic cathodoluminescence (SEM-PCL) analysis of >1200 individual sand-sized …
