Geology Commons^™

"The Course Of The Tennessee River", William Lindsey Mcdonald

Research Articles

The article describes the usual course of the Tennessee River and various geological theories for the direction of its course. In addition, it explores the specific geomorphology of the Muscle Shoals and its impact on North Alabama.

"Our Heritage From The People", William Lindsey Mcdonald

Writings

A lecture presented to a history seminar at the University of North Alabama in March of 1979. The lecture addresses the geography and geology of North Alabama, removal of indigenous people, cultural influence of settlers, and development of the Tennessee Valley into contemporary settlements.

Evolution Of Propagator Wakes On The Kolbeinsey Ridge From An Integrated Geophysical Perspective, Ethan Stowell

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Oceanic lithosphere is formed following the extension and rifting of a continent, with new material generated at mid-ocean ridges. While ridges generally spread in the direction of extension, individual spreading centers are offset by perpendicular transform faults that break the ridges into individual segments. Ridge propagation, in which one ridge segment grows at the expense of another’s shortening, has been identified in global investigations as a poorly understood component of axial reorganization. This process leaves propagator wake structures composed of faults and pseudofaults visible as lows in Earth’s gravitational field, and transferred lithosphere with a distorted magnetic signature. This study …

Minerals Rock!: Improving Audience Engagement And Interest In Stem Through Enhancement Of The In-Person And Online Mineral Collection At Ursinus College, Juliette Lyons

Environment and Sustainability Summer Fellows

Museums are a vital source of educational resources for the general public. They provide information on a variety of topics and disciplines and encourage visitors to be excited about and engaged in learning something new. As we work to comprehend key topics such as climate change, it is especially important for the broader public to better understand science, including geology. While the geological collection at Ursinus, Pieces of Earth’s History, is not in a museum, implementing methods that museums use can improve the reception of the collection. Through the application of research gathered through articles, journals, books, and talking with …

Glacier Elevation Difference Data For The Conterminous U.S., Andrew G. Fountain, Bryce Allen Glenn, Christopher Mcneil, Brian Menounos

Geology Faculty Datasets

Historic and recent elevation data for the glaciers in the conterminous US were differenced to estimate glacier mass and volume change.

Historic glacier elevations were obtained from the USGS National Elevation Dataset (https://doi.org/10.15760/geology-data.04), a digitized product from the USGS 1:24,000 paper topographic maps that included the glacier extent (Gesch, 2007). Recent glacier elevations were derived from aerial lidar and from satellite radar. The lidar data were largely obtained from the USGS 3D Elevation Program (Stoker and Miller, 2022; US Geological Survey, 2024), and filtered by acquisition date using only those data collected between mid-summer and early autumn. The …

An Overlooked Terrestrial Archive: Freshwater Cements And Hydroclimate Signals In Quaternary Glaciogenic Deposits, Owen F. Mccaffrey, Ian Z. Winkelstern, Tara A. Kneeshaw, Melinda C. Higley

University Faculty Publications and Creative Works

Quaternary glaciogenic deposits, which serve as vital groundwater aquifers, are often partially cemented with carbonate minerals, but the timing of emplacement of these cements and their geochemical conditions of formation remain understudied. Here, we integrated petrography, δ¹⁸O, Mg/Ca, and clumped isotope (Δ₄₇) data from two calcitecemented outcrops in western Michigan (USA) to investigate the origin of glacial sediment cements. The two sites have contrasting topographic and textural settings reflecting distinct formation conditions. The elevated Wabasis Lake deposit records sequential phreatic-to-vadose cementation, while the Cherry Valley Sands site, very close to the modern water table, shows a …

Interseismic Creep Along The Enriquillo–Plantain Garden Fault, Haiti, Estimated From Insar, Rishabh Dutta, Jeremy L. Maurer, Yi Chieh Lee

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Enriquillo–Plantain Garden fault zone (EPGFZ) is a major left-lateral strike-slip fault in southern Haiti hosting several recent destructive earthquakes, including the 2021 MW 7.1 Nippes event with primary thrust-slip. To investigate how strain is accommodated in the vicinity of the 2021 event, we analyzed Sentinel-1 interferometric synthetic aperture radar (InSAR) data from 2017 to 2021 using a PS + DS (persistent + distributed scatterers) InSAR time-series approach to overcome decorrelation in this highly vegetated region. We reveal interseismic creep along the EPGF and adjacent Grand'Anse–Sud border faults, with pure strike-slip mechanism and rates up to 9 mm/yr. We suggest …

Design Framework For Polymer Gel Treatments From A Database Of Field Projects, Baojun Bai, Munqith Aldhaheri, Mingzhen Wei

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This study compiles and analyzes data from over 125 published field projects around the world, covering nearly 900 treated wells. Building on those detailed studies, this paper distills the most important findings into a concise, practical, and actionable framework to guide where in-situ gel treatments should be applied, how they should be designed, and how their outcomes can be evaluated. The proposed workflow guides engineers through five integrated stages: screening appropriate gel types, designing formulation and injection strategies, predicting field response, evaluating treatment performance, and conducting iterative refinement with feedback loops to adjust designs based on observed outcomes. The framework …

Tectonics: Supporting Information For Deformation Rates And Patterns Of The Emerging Banda Ranges Revealed By Uplifted Coral Terraces In Timor-Leste, Ron Harris, Nicole Cox, Megan Flexhaug, Dorothy Merritts, Chua-Chou Shen, Frederico Santos

ScholarsArchive Data

The supplementary information provided consist primarily of figures detailing coral terrace profiles and terrace inner margin elevation to MIS highstand correlations.

• a general overview of the kind of data files;
• a general description of processing steps used;
• any known imperfections or anomalies in the data.

A Fiftieth Year Retrospective On The 1976 Mw 7.5 Motagua Earthquake In Guatemala, Grant Clark, Trenton Mcenaney, Jeremy Maurer, Andreas Eckert, Stephen S. Gao, Omar G. Flores, Robin Yani, Tina Niemi, Christoph Grützner, Francisco Gomez, Jonathan Obrist-Farner

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

On 4 February 1976, an Mw > 7:5 earthquake ruptured ∼240 km of the Motagua fault in Guatemala, causing ∼23,000 fatalities. This event provided evidence for the fault's role as a major transform boundary between the North American and Caribbean plates. Field observations, seismological analyses, and postseismic studies helped constrain fundamental aspects of the 1976 earthquake mechanics and the spatial complexity of the rupture. This event opened a window for studies documenting past deformation along this plate boundary across multiple spatial and temporal scales. Five decades of research have established this earthquake as an important event for understanding strike-slip ruptures along …

Crossing Boundaries: Brachinites And Their Diverse Asteroidal Origins, B. G. Rider-Stokes, F. A. Davies, T. H. Burbine, E. Maclennan, R. C. Greenwood, S. L. Jackson, M. Anand, Daniel Sheikh, M. M. Grady

Geology Faculty Publications and Presentations

Brachinite meteorites are typically linked to the olivine-rich A-type asteroids. In this study, however, they appear to exhibit unexpected spectral diversity. Spectroscopic analysis of seven meteorites from the brachinite clan reveals two distinct populations in band parameters, overlapping with both the A-type and S-complex asteroids. This dual association shows that a single meteorite group can originate from multiple asteroid taxonomies. Notably, one S-complex-like specimen, Northwest Africa (NWA) 14,635, displays band parameters similar to those of asteroid (65803) Didymos, the target of the European Space Agency's (ESA) ongoing Hera mission. These results underscore the value of spectroscopic characterization of poorly understood …

Reconstructing Nebraska’S Late Quaternary Paleoenvironment, Landscape Change, And Human–Environment Dynamics Using Diatoms And Optically Stimulated Luminescence Dating, Gosia Mahoney

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation examines Holocene environmental change and human–environment interactions in the Nebraska Sand Hills by integrating geomorphic, paleoenvironmental, and geochronological data. It presents three complementary studies that together explore how climatic variability, local landscape processes, and human activity influenced environmental systems.

The first study reconstructs the early Holocene evolution of a dune-dammed valley in the central Sand Hills. Stratigraphic, sedimentological, and diatom evidence indicate that eolian activity resulted in a blocked fluvial system, leading to elevated groundwater levels and the formation of a wetland that later developed into a lake. Notably, this transformation occurred under relatively dry conditions, demonstrating that …

Mechanism Of Improved Miscibility Of Co2–Oil Systems By Multiester-Headgroup Surfactants, Ning Xu, Yanling Wang, Baojun Bai, Yu Zhang, Wenjing Shi, Zhaonian Zhang, Wenhui Ding, Peixu Ma, Zan Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In the pursuit of carbon neutrality, the CO₂-enhanced oil recovery provides dual benefits by enabling both carbon sequestration and incremental oil production. However, its application is limited by high minimum miscibility pressure. CO₂-philic and oil-affinitive surfactants have emerged as an effective, low-dosage, and cost-efficient strategy to reduce the minimum miscibility pressure. In this study, macroscopic phase behavior experiments combined with molecular dynamics simulations were employed to systematically elucidate the influence of multiester-head surfactants on CO₂–oil miscibility. Using a modified pressure–volume–temperature apparatus equipped with optical power monitoring, we determined that multiester-head surfactants reduced the first-contact …

Plastic Purgatory: Investigating The Effects Of Plastic Litter On Water And Organic Content In Topsoil In Holland, Michigan, Kamryn Bice, Annis Cairns, Maddie Devries, Sebastian Lema

25th Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2026)

Plastic accumulation in soils can offer important insights into how human activity affects terrestrial ecosystems. In this study, we examined the relationship between plastic litter and soil quality at several sites across Holland, Michigan to determine whether plastic abundance was associated with changes in soil properties. Soil samples from five different site types – construction, residential, commercial, nature, and a control – were collected over a threeweek period, then analyzed for pH, water contents, total organic carbon (TOC), and plastic abundance through field testing and laboratory methods. The number of plastic pieces ranged from 0 to 27 with the largest …

Joint Map Of Warren County, Kentucky, Steven L. Martin, Emily R. Morris

Map and Chart--KGS

This fracture map is a compilation of joint locations and faults mapped in Warren County, Kentucky, and provides orientations of fractures (joints and faults) for hydrological, geotechnical, slope stability, and rockfall mitigation analysis. The joint data include orientations collected from 2023 to 2024, and those collected during the U.S. Geological Survey (USGS) geologic mapping of the Woodburn 7.5 -minute quadrangle (Shawe, 1963c). New joint orientations were measured to fill gaps in the published geologic map data. Joints are fractures with no appreciable movement parallel to the fracture plane and only slight movement normal to the fracture plane, whereas faults exhibit …

Machine Learning And Multisensor Data Fusion For Forest Above Ground Biomass Estimation In Arkansas, Abdullah Al Saim, Mohamed Aly

Geosciences Faculty Publications and Presentations

Forests are essential for biodiversity conservation, climate change, natural education, scientific research, and carbon sequestration. This study uses machine learning-based Random Forest (RF) regression to estimate the Above Ground Biomass (AGB) of the Ozark and Ouachita forests at a 10-meter resolution by combining data from Sentinel-2, Sentinel-1, and GEDI (Global Ecosystem Dynamics Investigation) on Google Earth Engine. The RF model included 34 out of 154 variables representing topographical, spectral, and textural factors demonstrating strong correlations with measured biomass. The RF model showed strong performance with R-squared and RMSE values of 0.95 and 18.46 for the training dataset and 0.75 and …

Perturbations To Horizontal Gnss Position Time Series By Atmospheric Lee Waves In The San Bernardino Valley, California, Walter Szeliga, Logan Grey

All Faculty Scholarship for the College of the Sciences

Anomalous systematic position offsets have been noted in GNSS time series from a variety of locations around the globe. In many regions, these time series anomalies coincide with the presence of cloud streets in visible satellite imagery, implicating atmospheric lee waves as the source of the position offsets. We report here on seasonal anomalous position offsets from the San Bernardino Basin of southern California that occur during clear skies. Modeling of the troposphere on days with anomalous positions shows the presence of atmospheric lee waves. Ray tracing through these tropospheric models suggests that atmospheric lee waves create low elevation perturbations …

Geology Lab Activities An Open Educational Resource For Community College Students And Instructors, Rondi Davies, Ari Nakamura

Open Educational Resources

I'm delighted to present the updated version of Geology Lab Activities, initially developed during the COVID-19 pandemic for online learning. As we have returned to the classroom, this revised edition remains a versatile educational tool for community college students, adaptable for both online and in-person classes.

This manual combines my preferred open-access materials with my own contributions, forming a cohesive resource for non-major geology students. Thanks to a CUNY OER grant, I partnered with graphic designer Ari Nakamura, whose innovative and elegant design has truly elevated the book.

Our labs are crafted to be engaging and relevant for non-major …

Evaluating Groundwater-Surface Water Interactions At Selected Streams In The Mississippi River Valley Alluvial Aquifer, Usa, And Comparison To Regional Potentiometric Surfaces, Joshua Michael Blackstock, Oladipo S. Obembe, Aaron Shew, Phillip Hays, Phillip R. Owens, Christopher D. Delhom

Geosciences Faculty Publications and Presentations

Field measurements of groundwater-surface water interactions (GWSW) are critical for quantifying stream leakage, but are often limited in availability. In the Mississippi River Valley alluvial aquifer (MRVAA), USA, GWSW interactions are often inferred through interpolated potentiometric surfaces, which can provide information on GWSW changes through time, but are often limited in spatial resolution. Field measurements of GWSW interactions were conducted at several locations and compared with potentiometric surfaces using objectively calculated cell sizes. The potentiometric surfaces showed similar regional-scale groundwater-flow patterns irrespective of grid cell size. Field measurements of GWSW interactions exhibited a broader range of gaining and losing conditions …

Microbial Communities And Biogeochemistry Of A Melting Rocky Mountain Glacier, Pacifica Sommers, Elizabeth Traver, Alison Orthel, Andrew G. Fountain, Jacki Klancher, Steven K. Schmidt

Geology Faculty Publications and Presentations

Mountain glaciers are disappearing rapidly, and with their disappearance, we may be losing unstudied biodiversity and genetic resources. A variety of habitats for microorganisms exist on glaciers, especially within pockets of supraglacial sediments (cryoconite) that support high levels of biological activity and diversity. We used biogeochemical approaches, high-throughput DNA sequencing, and microscopy to describe the biogeochemistry and microbial communities of supraglacial sediments on the Dinwoody Glacier in the Wind River Range, Wyoming. Carbon (C) and nitrogen (N) concentrations were high, and C:N ratios were close to the Redfield ratio indicating active nutrient cycling. We found unique microbial communities in sediments …

Effect Of Ionic Strength On Gelation Time And Strength Of Amps-Based Polymer Gels, Maryam Sharifi Paroushi, Xuyang Tian, Baojun Bai, Thomas P. Schuman, Yin Zhang, Mingzhen Wei

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Polymer gel treatment has been widely applied for improving sweep efficiency and controlling excessive water and gas production. Their performance depends on gelation time and final gel strength. In most studies, brine salinity is used to describe the effect of formation water on gel behavior. However, changing salinity also changes ionic strength and ion composition at the same time. Because of this coupling, it is difficult to identify the mechanisms controlling gelation, which has led to inconsistent trends in the literature. Increasing salinity has been reported to either slow or accelerate gelation and to weaken or strengthen gels depending on …

Nebraska Statewide Groundwater-Level Monitoring Report 2025, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Jeffrey Westrop

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Evaluation Of Chromium-Crosslinked Amps-Hpam Copolymer Gels: Effects Of Key Parameters On Gelation Time And Strength, Maryam Sharifi Paroushi, Baojun Bai, Thomas P. Schuman, Yin Zhang, Mingzhen Wei

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Controlling CO₂ channeling in heterogeneous reservoirs remains a major challenge for both enhanced oil recovery (EOR) and secure geological storage. AMPS-HPAM copolymers exhibit high-temperature resistance and brine tolerance compared with conventional HPAM gels, making them well suited for the harsh environments associated with CO₂ injection. Chromium-based crosslinkers (CrAc and CrCl₃) were investigated because sulfonic acid groups in AMPS can coordinate with trivalent chromium ions, enabling dual ionic crosslinking and the formation of a robust gel network. While organic crosslinked AMPS-HPAM gels have been widely studied, the behavior of chromium-crosslinked AMPS-containing systems, particularly their gelation kinetics under …

Solubility And Dissolution Mechanism Of Novel Multi-Ester Headgroup Surfactants In Supercritical Co2, Ning Xu, Yan Ling Wang, Baojun Bai, Shi Zhang Cui, Yu Zhang, Wen Jing Shi, Zhao Nian Zhang, Wen Hui Ding, Pei Xu Ma, Zan Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To address the limited solubility and applicability of conventional hydrocarbon surfactants in supercritical CO₂, a series of multi-ester headgroup surfactants were designed and synthesized by leveraging the CO₂-philic properties of ester groups. The molecular structures were characterized using Fourier transform infrared (FT-IR) spectroscopy and ¹H NMR. A custom-designed laser-based apparatus was developed to quantify surfactant solubility and systematically investigate phase behavior in CO2. Molecular dynamics (MD) simulations were employed to elucidate structure–solubility relationships across multiple scales, including solubility parameters, interaction energies, radial distribution functions (RDFs), and free volume fractions. Results indicate that, at 323.15 K, …

Evaluation Of A Novel Re-Crosslinkable Preformed Particle Gel For Conformance Control In Ultra-High Temperature Reservoirs, Yanbo Liu, Tao Song, Caleb Kwasi Darko, Thomas P. Schuman, Mingzhen Wei, Baojun Bai

Chemistry Faculty Research & Creative Works

Preferential fluid flow remains a major challenge in subsurface energy production and gas storage operations, resulting in excessive water production in mature oil fields, reduced heat extraction in geothermal reservoirs, and low sweep and storage efficiency in CO₂-EOR projects. Polymer gels are widely used to mitigate high-permeability channels; however, conventional systems exhibit limited plugging efficiency and short lifetimes in ultra-high-temperature reservoirs due to poor thermal stability. This study presents a novel ultra-high-temperature-resistant preformed particle gel (UHT-PPG) developed for conformance control in reservoirs with temperatures of 150–275 °C and severe super-K or channeling problems. The material was evaluated in …

Testing The Limits Of Provenance Analysis From Basaltic Fluvial Sediment Near Sandvatn, Iceland, As A Mars Analog, Audrey R. Putnam, Kirsten L. Siebach, Michael T. Thorpe, Valerie M. Tu, Elizabeth B. Rampe, Candice C. Bedford, Gelu Costin, Joseph J. Tamborski

OES Faculty Publications

Detrital sediments that accumulate downstream and are preserved in sedimentary rocks can allow characterization of geologic formations that are inaccessible for spatial or temporal reasons. However, mixing, sorting, and alteration of sediment during transport may complicate reconstruction of protolith characteristics. We test the preservation of three key provenance signals in coarse fluvial sand at a Mars analog watershed in Iceland to determine whether detrital sediments capture (a) watershed magmatic chemical variation, (b) textural indicators of lava-water interaction during eruption and cooling, and (c) hydrothermal alteration. Specifically, we tested whether diagnostic variations in rock mineralogy, chemistry, and texture can be recovered …

The Effects Of A Microplate On Plume-Ridge Interactions: Constraints From Comparing Easter And Juan Fernandez Microplates In The Eastern Pacific Ocean, Katherine Ames, Jennifer Georgen

OES Faculty Publications

This study investigates the nature of plume-ridge interactions near a tectonic microplate using mantle Bouguer anomaly (MBA) gravity calculations. The focus of this investigation is a comparison of the Easter and Juan Fernandez microplates, which are located in the eastern Pacific Ocean along the Pacific, Nazca, and Antarctic plate boundaries. The microplates have several similar characteristics, including general size, time of formation, and clockwise rotation within the larger bounding mid-ocean ridge systems. Unlike the Juan Fernandez microplate, however, the Easter microplate is located near a mantle plume (Easter/Salas y Gomez). Previously published geochemical data suggest that material from this plume …

Fulbright Project In Iceland In The Summer Of 2026, Irina Filina

Nebraska Academy of Sciences: Programs and Proceedings

This upcoming Fulbright project is inspired by an ongoing debate in the scientific community about the tectonic origin of Iceland. A long-standing theory of Iceland’s formation by excessive magmatism at the Mid-Atlantic spreading center over the well-known hot spot (i.e., oceanic crustal affinity) was recently challenged by the alternative hypothesis that the Icelandic crust is continental in nature and is being stretched and gradually modified by magmatic processes. Based on this hypothesis, a new sunken continent, Icelandia, has been proposed. One of the foundations for the proposed Icelandia is the presence of felsic lavas (indicative of continental flavor in the …

Supplemental Bibliographic Details. From 2001 Mars Odyssey To Earth’S Climate Crisis: Integrating Gamma Spectroscopy, Martian Soil Simulants, And Plant Genomes For Agroecology, Anchored In Sri Lanka’S Mars-Context Serpentinites, Suniti Karunatillake, Maheshi Dassanayake, Carlos Gary Bicas

Planetary Science Lab

Bibliographic details follow to supplement hyperlinked citations in the multinational GANGOTRI-supporting project conceived by Karunatillake, Dassanayake, and Gary-Bicas

Last Glacial Maximum And Late Glacial Aeolian Sand Activity, South-Central Indiana, Usa, H. M. Loope, J. L. Antinao, P.R. Hanson, P. M. Jacobs, D. A. Grimley

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.