Digital Commons Network^™

Late Cretaceous Ammonites And Other Non-Rudist Mollusks From Costa Rica And Their Paleoecology, Esteban David Lopez-Murillo

Earth and Planetary Sciences ETDs

The Nicoya region in northwestern Costa Rica contains a rich record of Upper Cretaceous fossiliferous sediments, which have received variable levels of study over the past several decades. In particular, rudists from these deposits have been well-characterized, however, the non-rudist ammonite, gastropod, and bivalve fauna have received much less attention. However, this area is particularly important because the Nicoya region was attached to the southernmost tip of North America, making it a unique crossroad between the western Tethys (Caribbean) and Pacific Oceans. Here I present a detailed investigation of these rocks and their fauna between the Late Campanian to Early …

Evaluating The Physics-Based Slope Stability Program Pisa-M At A Regional Scale, Hudson J. Koch, William C. Haneberg, Matt M. Crawford, Jason M. Dortch, Meredith Swallom

Report of Investigations--KGS

Physics based landslide modeling can be difficult and data intensive. Generating high quality and practical map results is often not feasible outside of small, thoroughly characterized study areas. Using the physics based program Probabilistic Infinite Slope Analysis (PISA m), users can perform expedient assessments of landslide hazard over large study areas where comprehensive geotechnical data may be lacking, but other data inputs are robust. PISA m uses an infinite slope equation and spatial layers, such as a digital elevation model (DEM), a lidar derived forest cover layer, and a soil map, to calculate the probability that the factor of safety …

Clay Minerals Origin And Paleoclimate Implications In Quaternary Deposits Of The Saïs Plain, Fez-Morocco, Ayman Agharabi, L. Karrat, Frank R. Ettensohn, N. Har, L. Gourari, H. Bedelean, C. Balica, C. V. Mircescu

Earth and Environmental Sciences Faculty Publications

The city of Fez in northern Morocco is situated on northeastern parts of the Saïs Plain, an alluvial basin. It is spreading southwesterly onto Pleistocene sediments consisting primarily of alluvial, channel-fill conglomerates and overbank deposits, as well as Holocene tufas. As urban develop- ment expands, human activities are increasingly eradicating these deposits, about which little is known. This study focuses on the clay-mineral composition of these Pleistocene overbank de- posits, informally known as the “Red” and “Yellow” units, as well as of the Holocene tufas. In contrast to previous research that has emphasized the industrial uses of nearby Miocene marls. …

Mineralogic Control On The Calcium And Magnesium Stable Isotopic Compositions Of Modern Microbial Carbonates, Elizabeth M. Griffith, Matthew S. Fantle, Brittan V. Wogsland, Zijian Li, Majie Fan, David J. Wronkiewicz

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Modern microbialites grow in a variety of environments including the hypersaline, turbid, low alkalinity, high magnesium (Mg) and calcium (Ca) concentrations (and Mg/Ca ∼ 4.5 mol/mol), shallow (less than 2 m deep) Storr's Lake on San Salvador Island, The Bahamas. Rather than growing via the trapping and binding of sediments, these largely micritic microbialites form via microbial processes creating crusts and mounds with laminated to clotted structures comprised of both high-Mg calcite and aragonite. The primary objective of this study was to determine whether the mineralogy of representative microbialite mounds dictates their pre-burial metal isotopic compositions. The Mg and Ca …

Easternmost Limit Of Sevier Orogeny, East-Central Utah Revisited, Kenneth R. Neuhauser

SACAD: Scholarly Activities

Integrative field mapping combined with published and unpublished seismic profiles, support an inferred, easternmost limit of Sevier thrusting during Late Cretaceous foreland deformation in east-central Utah. East-verging thrust faults, drag folds, and chatter marks within Jurassic and Late-Cretaceous exposures at Ketobe Knob along the western margin of Cedar Mountain in the northwestern and central parts of the San Rafael Swell and within the western zone of the Colorado Plateau provide evidence for a more easterly expression of the Sevier Thrust Front. Offset is accomplished by bedding-parallel slippage along less competent shales and siltstones and by oblique ramping across more competent …

Quality Control Of Transportation Construction Aggregate Using Laser Scanning – Kdot Part 1, Kenneth R. Neuhauser

SACAD: Scholarly Activities

Laser scanning of transportation aggregate materials provided a means to identify aggregate types, sources, and quality in near-real time. A multi-state project led by the Kansas Department of Transportation (KDOT) and facilitated by Chesner Engineering (Coeymans, New York) used laser ablation breakdown spectroscopy (LIBS) to determine whether the technique could be used to predict durability (D)-cracking aggregate susceptibility and whether LIBS could be evaluated to ensure that the source materials were all derived from approved materials. This poster focuses only on the Kansas portion of the project. Six years of study indicates that LIBS may be used as a quality …

A Bibliometric Study Of Astronomy And Geoscience Doctoral Dissertations, Nora Boyle, Mary Schlembach

Faculty Journal Articles

A bibliometric analysis was conducted over the bibliographies of astronomy and geology doctoral dissertations written between 1970 and 2020 in order to review the document types that are utilized and cited. An investigation was made of various cited reference ages and how cited references in dissertations have evolved with the advent of electronic resources and preprint services. Our study examined 50 astronomy and 50 geology dissertations with 10 dissertations selected from each decade (n = 100). Results measured included 13,475 total references and the study found that references to journal articles increased, and book citations have decreased in both …

Shock Effects Including Maskelynite Formation In Three Shergottite Meteorites From Mars, George Ayeh Anim

Dissertations and Theses

Martian meteorites result from large impact events on the surface of Mars that cause intense shock metamorphism. This study examines the shock metamorphic features of three shergottite meteorites, Dho 019, NWA 12241, and NWA 15628, to better understand shock impact events. The research uses petrographic analysis, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and electron backscatter diffraction (EBSD) to analyze the meteorites. A key focus of this research is the formation of maskelynite, a glass with plagioclase composition, whose formation mechanism has been the substance of debate among researchers. This study proposes that maskelynite forms through a transient intermediary …

Application Of Convolutional Neural Network For Seismic Event Classification: Impact Of Dataset Quality, Distribution, And Human-In-The-Loop Feedback, Yanwei Zhang, Stephen S. Gao, Xiaoyi Fan, Shaohui Zhou, Junhao Qu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Convolutional neural networks (CNNs) have gained popularity in geophysical research due to their exceptional performance in various areas. However, achieving reliable results with CNNs typically requires a significant amount of high-quality data for training. In this study, we develop a CNN to classify natural earthquakes, mine collapses, and explosions using seismic waveforms from 287 stations in Shandong Province, China. The dataset comprises 1035 earthquakes, 159 mine collapses, and 586 explosions. To address the impact of unreliable measurements, we employ cross validation to screen, manually correct, or discard measurements with inconsistent labels assigned by human experts and CNN. By refining the …

Reinforcing Polymer Flooding System With Dendritic Mesoporous Silica Nanoparticles For Improved Oil Recovery, Di Li, Yanling Wang, Baojun Bai, Ning Xu, Wenjing Shi, Yu Zhang, Wenhui Ding, Peixu Ma, Zan Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Dendritic mesoporous silica nanoparticles (DMSNs), characterized by a high specific surface area and abundant hydroxyl groups, offer a promising approach to enhancing the performance of amphiphilic polymers in challenging enhanced oil recovery (EOR) conditions. In this study, DMSNs were successfully synthesized, and systematically evaluated for their impact on the solution properties of a betaine amphiphilic polymer (PADC). The unique "flower-like" mesoporous structure of DMSNs provided approximately 7-fold higher surface area than conventional SiO2, facilitating enhanced polymer-nanoparticle interactions. The DMSN/PADC composite system exhibited significantly improved viscosity, salt resistance, thermal tolerance, and shear resistance compared to PADC and SiO2/PADC systems. Quantum chemical …

Diffendal Receives Wisherd Award For University Service, Ronica Stromberg

Robert F. Diffendal, Jr., Publications

Even though he’s retired, Robert Diffendal seems to be working everywhere.

The professor emeritus in the School of Natural Resources retains offices in three buildings. He reports to work at the Center for Great Plains Studies five days a week for about four hours a day. His list of volunteer activities around the state goes on and on, affecting, by his count, 21,088 people since 2003, when he stepped away from full-time faculty work. He capped 2024 at Nebraska Innovation Campus, where he received the Wisherd Award for Outstanding Service to the University of Nebraska–Lincoln.

Chosen by the Emeriti and …

Analysis And Description Of The Iridescent Film On Calcites In Eastern Iowa, Cavit Schempp, John Oostenryk

Geology: Student Scholarship & Creative Works

During the Devonian Period, eastern to central Iowa experienced multiple transgressive and regressive intervals. This study focuses on the Cou Falls and Gizzard Creek Members of the Coralville Formation, deposited during the Eifelian Stage. Sometime after the formation of the limestone, the interiors of various brachiopods, gastropods, and other fauna began to weather out, creating vugs within the limestone, which gave rise to the first of three growth phases of calcite in the form of rhombohedrons and scalenohedrons. After these primary calcites were formed, new fluids flowed through these vugs, depositing a previously misidentified iridescent film on the calcite crystals, …

Provenance Of Clastic Rocks In The Inner Hornsund Trough, Svalbard, Noah Riccardi

Geology Honors Projects

Late Paleozoic clastic sedimentary rocks in the Inner Hornsund Trough (IHT) in southern Svalbard represent an archive of regional tectonic events and are key to accurate paleogeographic reconstructions of the Arctic. To tap this archive, ~1800 detrital zircon grains were separated and analyzed from six total samples of sedimentary rock, including samples from both sides of the Hornsund fjord. Two samples came from the Marietoppen formation (Late Devonian), and four from the Adriabukta formation (Late Devonian and/or earliest Carboniferous). Detrital zircon U-Pb age spectra from both units are similar, with the majority of analyzed grains falling in the 1.0-2.0 Ga …

Caves, Calculus, And Climate Change: Measuring And Modeling The Discharge Of Biz Falls In Mammoth Cave National Park, Ava Lich

Mahurin Honors College Capstone Experience/Thesis Projects

Climate change poses a significant global challenge, with increasing levels of atmospheric carbon dioxide as a primary driver of rising temperatures and environmental disruptions. Karst systems, such as those in South-Central Kentucky, play a role in sequestering atmospheric CO₂ through the dissolution of limestone, a process that forms unique landscapes while mitigating climate impacts. This study investigates the discharge dynamics of Cascade River in Great Onyx Cave to enhance understanding of the relationship between hydrology and carbon sequestration in karst environments. A barrel weir equipped with pressure transducers was employed to collect and measure water flow, and Torricelli’s law was …

Investigating Woody Vegetation Recruitment Post Riparian Enhancement Extraction Along The Baduwa't, Rize Martins De Oliveira, Wiley Hughes, Owen Lenox

Forestry, Fire, & Rangeland Management Senior Capstones

The Baduwa’t River in Humboldt County, California, faces a legacy of channelization, poor land management, and severe flooding that has left high, dry floodplain terraces disconnected from the river and dominated by invasive vegetation. In response to sediment deficits during drought years, Riparian Enhancement Extractions (REEs) were introduced as an alternative gravel mining method that simultaneously presented opportunities for habitat restoration. This study evaluates five REEs along the Baduwa’t to identify the construction features and site conditions that promote successful riparian vegetation establishment. Findings show that REEs can create seasonal wetlands conducive to native riparian habitat reestablishment, when excavation is …

Sedimentary Archives Of Late Quaternary Limnological, Ecological, And Environmental Change In The Eastern Sierra Nevada (California, Usa), Bailee Hodelka

Theses and Dissertations--Earth and Environmental Sciences

The Sierra Nevada essentially serve as the headwaters of California, providing crucial freshwater to the state through seasonal snowmelt. This water supply is threatened by climate change in complex ways that are not fully understood. Geological records provide a valuable source of information on how the hydrology, limnology, and ecology of the Sierra Nevada region has responded to climate changes of the past. This dissertation presents new sedimentary and paleoecological research from Mono Lake and Convict Lake (Mono County, California) and aims to shed light on environmental changes in the eastern Sierra Nevada from ~16 ka to present.

At Mono …

Stratigraphy And Osl Chronology Of Lunette Deposits Indicates That Nebraska’S Rainwater Basins Formed By Aeolian Deflation Between 39 And 25 Ka, P.R. Hanson, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Yukon Dust From Source To Sink: Characterizing The St. Elias Mountains As A High-Latitude Dust Source, Audrey Y. Lemoine

Honors Theses

High-latitude dust is an important, yet poorly understood, component of Earth’s climate system. It impacts weather and albedo by acting as cloud condensation nuclei, directly affects Earth’s radiative balance, and can enhance productivity by supplying nutrients to ecosystems. In order to better understand high-latitude dust dynamics and impacts, we sampled glacial meltwater, surface sediment, and Holocene loess in the Łhù’ààn Mân (Kluane Lake) region of the Yukon Territory, Canada. We found that suspended sediment concentration is correlated with average slope and glaciation within a catchment, and is influenced by river morphology. We present new εNd and ⁸⁷Sr/⁸⁶Sr …

Water Quality And Microplastic Contamination In An Urbanizing City Nakhon Pathom, Thailand, Boonyarak Chuanchit

Graduate Research Theses & Dissertations

Microplastics (MPs) are synthetic polymer particles less than 5 mm in size that originate from both primary manufacturing and the breakdown of larger plastics. Extensive studies have examined their occurrence in other environments, while little is known about their presence and behavior in groundwater, especially in urbanizing regions in Southeast Asia. This study investigates the occurrence and abundance of microplastics within groundwater systems of Nakhon Pathom, an urbanizing province in central Thailand.

Groundwater was collected representing shallow and deep aquifers between May 2023 and May 2025. The analyses included physical-chemical parameters, major ions, heavy metals, and microplastic abundance and composition. …

Spatiotemporal Economic Impact Analysis Of The Taal Volcano Eruption Using Electricity Consumption And Nighttime Light Data, Ma Flordeliza P. Del Castillo, Toshio Fujimi, Hirokazu Tatano

SOSE Affiliate: Manila Observatory

Analyzing the spatiotemporal dimension of the economic impacts of disasters is critical for providing timely and proportionate support. However, traditional economic impact measures often lack spatiotemporal details. Hence, we estimated the daily electricity consumption (EC) loss using high-frequency EC data and analyzed temporal dimensions of the immediate impacts of Taal Volcano’s eruption on January 12, 2020. Subsequently, we computed the nighttime light (NTL) change using high-resolution NTL data to analyze the spatial distribution of these impacts. The temporal analysis revealed two EC loss peaks. The first peak coincided with the power outage and decreased energy demand, followed by a brief …

Heat Treatment Of Basaltic-Related Sapphire From Binh Thuan Deposit, Southern Vietnam, Yuparat Kwangsawat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Characteristics of basalt-related sapphires from Binh Thuan in Southern Vietnam were investigated before and after heat treatment. Samples were divided into four group, based on their color and hue including dark blue, blue, greenish blue, and bluish green. After being heated at 700-1000°C, sapphires' blue hue faded noticeably. Blue color turned to be intensified when heated at 1650°C. Subsequently, beryllium-assisted heating by a local professional gem treater was introduced to these sapphire samples which in turn yielded yellow to yellowish-blue hues. Color changes after heating are conclusively involved by trace compositions of sapphire and temperatures of heating. The appropriate treatment …

Early Holocene Interaction Of Aeolian, Alluvial, And Lacustrine Processes In A Dune-Dammed Valley In The Central Nebraska Sand Hills, Gpsia Mahoney, R. D. Mandel, P.R. Hanson, Sherilyn Fritz

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Characterization And Leaching Feasibility Studies Of Copper Flue Dust For The Recovery Of Main And Trace Metals, Fardis Nakhaei, Marek Locmelis, Lana Alagha, Michael S. Moats, Carlos Eyzaguirre, Cory Smith

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Although copper smelter dust (CSD) is classified as hazardous waste, it also serves as a valuable secondary resource, offering potential for the recovery of critical elements. In this study, CSD samples were collected from the waste heat boiler (WHB) and electrostatic precipitator (ESP) units connected to the flash smelting furnace at a copper smelter. The representative samples were extensively characterized by particle size, and chemical and mineralogical analyses. Following sample characterization, leaching experiments were performed to evaluate the potential extraction of Cu, Fe, As, Zn, Pb, In, Ga, and Ge from the flue dusts. Distilled water, H2SO4, and HCl were …

Distribution And Tooth Morphoguilds Of Mosasaurids (Squamata) Of The Campanian Western Interior Seaway With Implications For Controls On Mosasaur Paleobiogeography, Alec Zaborniak

Master's Theses or Doctor of Nursing Practice

The Western Interior Seaway (WIS) of North America is well known for its mosasaurid squamate diversity, particularly during the Campanian of the Late Cretaceous. Mosasaurid diversity has historically been examined at a fine scale, with many studies investigating the faunal composition of specific assemblages; however, studies focusing on mosasaur communities within the Western Interior Seaway during specific Ages are currently lacking. Mosasaur tooth morphology has also been extensively studied, with tooth characteristics commonly being used as phylogenetic characters. However, many studies examining mosasaur communities and tooth morphology have been focused on broader spatiotemporal or phylogenetic scales. This study investigates the …

The Effects Of Return To Prairie In Barber County, Kansas: A Case Study Using Ndvi And Dendrochronology, Elijah O. Joy

Master's Theses or Doctor of Nursing Practice

This study aims to evaluate the impact of prairie restoration efforts in Barber County, Kansas, with a focus on removal of Eastern Red Cedar. Restoration effectiveness was assessed using remote sensing of satellite scenes via NDVI, density analysis, and dendrochronological methods. The tree density analysis revealed a 66% reduction across the study area and a 99% reduction in the fully restored zones. NDVI analysis from 2010 to 2024 showed higher summer vegetation health and seasonal fluctuations influenced by climate variability and fire events. Dendrochronological data from tree cores reveals growth patterns and establishes a baseline for future dendrochronological chronologies. The …

Oil-Oil Correlation Across Sedimentary Basins In Kansas Using Molecular Geochemistry And Fourier Transform Infrared Spectroscopy, Oluwaseun V. Omoyemi

Master's Theses or Doctor of Nursing Practice

Hydrocarbons are produced from different subbasins and stratigraphic intervals in Kansas. However, the geochemical characteristics and sources of these hydrocarbons are still poorly understood. While reservoir rocks, seals, and traps that are essential for petroleum systems are well defined within the state, the possible source rocks are often considered thermally immature, raising questions about their ability to generate the volume of hydrocarbons currently being produced. This research project tries to evaluate the geochemical characteristics of hydrocarbons produced in the state of Kansas and determine if the hydrocarbons from the different subbasins and stratigraphic units are genetically related. Thirty-seven crude oil …

A Histological Survey Of A Large, Sub-Adult Tylosaurus Nepaeolicus With Implications On The Validity Of Tylosaurus Kansasensis, Carson Cope

Master's Theses or Doctor of Nursing Practice

Tylosaurus nepaeolicus is a basal, medium-sized tylosaurine mosasaur that lived during the late Coniacian and early Santonian in the Western Interior Seaway. Despite being a well-studied species, there is debate over whether Tylosaurus kansasensis represents the juvenile form of T. nepaeolicus, or if the two species are distinct. Osteohistology can determine organism age at time of death and can be used to help resolve this debate and provide a better understanding of the growth of T. nepaeolicus. Thin-sections were taken from a humerus, rib, and vertebra of a single individual (FHSM VP-2209). All thin-sections show primarily parallel-fibered cortical …

Geochemical And Sedimentological Signals Of Bottom Water Oxygen Dynamics From Lake Tanganyika (Zambia), Njahi Mwangala

Theses and Dissertations--Earth and Environmental Sciences

Lake Tanganyika is a large, ancient freshwater body with exceptional biodiversity that is located in the East African Rift System. Lake Tanganyika’s size and longevity make its sedimentary record useful for understanding environmental changes that cross spatial and temporal boundaries. Lake Tanganyika is known to be susceptible to global warming given its tropical location. Over 12 million people living within Lake Tanganyika’s watershed rely on fishing for their income and nutrition. Changes to limnological function driven by climate could therefore have serious implications for human health and biodiversity conservation. This study focuses on using geochemical properties of modern lake bottom …

Late Holocene Paleolimnology Of Lake Tanganyika (East Africa), Leandro Domingos Luz

Theses and Dissertations--Earth and Environmental Sciences

Understanding the long-term responses of ecosystems to climate variability is crucial for predicting and mitigating future changes in the Afrotropics, a region where a significant portion of the population is highly vulnerable to extreme climatic events. Lake Tanganyika, the largest rift lake in East Africa, offers a unique sedimentary archive that can be used to investigate the limnological changes, hydroclimatic shifts, and vegetation dynamics across various timescales. A multi-proxy approach was employed to assess the landscape responses to hydroclimatic fluctuations in the Late Holocene, integrating paleoenvironmental records from radiocarbon-dated sediment cores. This approach involved sedimentology, mineralogy, geochemistry, phytolith analysis, and …

Applications Of Remote Sensing Data To Understanding Geohazards In Wyoming And Kentucky, Meredith Swallom

Theses and Dissertations--Earth and Environmental Sciences

Shallow geohazards such as earthquakes, landslides, and floods profoundly impact communities globally. Constraining susceptibility to these hazards is critical for effective hazard mitigation and building more resilient communities. This dissertation includes multiple studies that leverage remotely sensed datasets to address hazard susceptibility, including: (1) characterizing a potential northern extension of the Teton fault system, (2) deriving a vegetation-based metric to improve landslide susceptibility maps in eastern Kentucky, with potential global implications, and (3) combining numerical modeling, landscape models, and field constraints to understand how anthropogenic factors affect flood severity in southern Appalachian catchments.

In the first study, analysis of new …