Geology Commons^™

Mgrre_Thinsections_Mgrre-138_88, Mgrre

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Mgrre_Thinsections_Mgrre-139_2, Mgrre

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Mgrre_Thinsections_Mgrre-139_29, Mgrre

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Mgrre_Thinsections_Mgrre-139_64, Mgrre

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Mgrre_Thinsections_Mgrre-139_69, Mgrre

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Mgrre_Thinsections_Mgrre-139_57, Mgrre

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Mgrre_Thinsections_Mgrre-139_74, Mgrre

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Response Of Botovskaya Cave To Local And Regional Environmental Dynamics, Jade Margerum, Oksana Gutareva, Franziska Lechleitner, Maria Box, Stuart Umbo, Anton Vaks, Hanno Meyer, Aleksandr Kononov, Aleksander Osintsev, Dimitri Sokol'nikov, Norbert Marwan, Ola Kwiecien, Sebastian Breitenbach

International Journal of Speleology

Speleothems from caves in near-permafrost regions can provide unique insights into the climatic history of temperature-sensitive environments. These regions are often remote and only seasonally accessible, which makes cave monitoring – a requirement for speleothem-based proxy interpretation – challenging. We document ventilation, the infiltration regime, and the isotopic composition of dripwater in Botovskaya Cave in southern Siberia, a host to speleothems previously used to reconstruct Quaternary permafrost dynamics in continental Eurasia. We explore surface and cave temperature records, cave air CO₂ concentration data and stable isotopes in precipitation and dripwater and evaluate infiltration conditions and the sensitivity of speleothems …

Pedagogy On Teaching A Totally Blind Student Physical & Historical Geology & Labs, Kenneth R. Neuhauser

SACAD: Scholarly Activities

Teaching the salient points of both physical and historical geology and labs to a totally blind student was accomplished through pre-planning, extra staff, daily preparation, low-cost supplies, teamwork, and at times ‘on-the-spot’ creativity.

Exceptional Variety Of Baryte-Celestine-Series Speleothems In Lechuguilla Cave (New Mexico, Usa), Max Wisshak, Johannes Birkenstock, Andrea Schröder-Ritzrau, Norbert Frank, Hazel A. Barton, Harvey R. Duchene

International Journal of Speleology

An inventory of speleothems primarily composed of the closely related sulfate minerals baryte (BaSO₄) and celestine (SrSO₄) in Lechuguilla Cave (New Mexico, USA) has revealed an extraordinary variety. This includes subaerial stalactites, stalagmites, flowstone, coralloids, wall crusts, floor crystals, snow, frostwork, and subaqueous pool crystals. Large baryte and celestine crystals have also been documented in hydrothermal veins in the host rock, predating the cave and truncated when intersected by it. The respective carbonate mineral phases witherite (BaCO₃) and strontianite (SrCO₃), in contrast, were found to be rare in the studied speleothem samples, …

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 …

Pitfalls Of Multiplied 3d Landforms Projection: Mapping Deep Multilevel Cave Systems In The Alps (Gamssteig Cave System, Göll Massif), Mateusz Golicz, Jacek Szczygieł

International Journal of Speleology

Cave mapping represents one of the most complex challenges in geomorphological cartography, as it must convey the true three-dimensional geometry of subterranean spaces such as overlapping passages, irregular cross-sections, and variable ceiling and floor morphologies, within a two-dimensional framework. This study examines the methodological and interpretive challenges of cave mapping, utilizing the Gamssteighöhle cave in the Austrian Alps as a case study. During the 11 years of exploration, over 10 km of passages were surveyed using the DistoX vector survey method. Yet, the complex morphological forms necessitated deviations from the standard symbology recommended by the International Union of Speleology. Several …

Ureilite Meteorite Petrofabrics: Evolution And Formation Deformational Conditions, Benjamin Botwe Agyemang

Dissertations and Theses

This thesis examines the origin and development of crystallographic fabrics in ureilites, which are primitive achondritic meteorites interpreted as residues of partial melting from a differentiated parent body. In this study, we evaluate three fabric-forming mechanisms: gravitational cumulate crystallization, shock-induced deformation, and flow alignment associated with melt extraction and convective stirring. A quantitative Electron Backscatter Diffraction (EBSD) analysis was conducted on six ureilitic meteorites to assess olivine Lattice Preferred Orientation (LPO), Shape Preferred Orientation (SPO), the connection between SPO and LPO, and other deformation metrics, including Grain Orientation Spread (GOS), and Crystal Rotation Axis (CRA). Our results suggest that most …

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 …

Exploring Mesoproterozoic Marine Redox States In A Young Banded Iron Formation From The Needle Mountains, Jaya Sharma, Brenhin Keller

Wetterhahn Science Symposium Posters

Banded iron formations (BIF), as redox-dependent chemical sedimentary rocks, have served as proxies for marine and atmospheric oxygen and iron conditions throughout Earth history. While abundant in the Archean and early Proterozoic, the widespread deposition of BIFs declined following the Great Oxidation Event, as oxygenated surface waters prevented the accumulation of ferrous iron. However, the Needle Mountains, located in southwestern Colorado, houses an anomalously young BIFs deposited between 1.786±10 - 1.801±6 Ga given existing geochronology. Here, we use rare earth element (REE) systematics, bulk chemistry, and petrographic analysis to determine the depositional conditions under which this BIF was formed. We …

Timing, Orbital Pacing, And Provenance Of Late Paleogene Loess In The Western United States, Xiangwei Guo

Earth & Environmental Sciences Dissertations - Archive

This project examines the timing of loess emergence, the nature of the fluvial–eolian transition, orbital forcing on dust accumulation, and sediment recycling in the late Paleogene White River Formation (Group) of Wyoming and Nebraska, western United States. By integrating traditional sedimentology with machine learning–enhanced grain-size analysis, this research shows that loess accumulation at Flagstaff Rim in central Wyoming began during active fluvial deposition at approximately 35.8 Ma, indicating a gradual transition from fluvial to eolian conditions. Machine learning complements field sedimentology and granulometric interpretation while enabling the development of new, testable hypotheses. Extending this framework eastward to Toadstool Geologic Park …

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 …

Empirical-Based Model Of Spatio-Temporal Errors, Godwin Naaba Ndaa

Masters Theses

This research develops an empirical model to characterize spatial-temporal InSAR errors and improve the accuracy of deformation time-series analysis. Using standardized Sentinel-1 HyP3 products and MintPy, the study quantifies how correlated noise affects velocity precision and validates the results against continuous GNSS velocities.

Residual velocities are near-Gaussian, with σ ~0.92–2.04 cm/yr and ~1 cm/yr on average. Variograms show power-law spatial structure with a non-zero nugget implicating troposphere and decorrelation while errors drop exponentially with more acquisitions; spatial uncertainty is strongly affected by unwrapping errors, coherence, and tropospheric noise, not simply troposphere.

A comparative assessment of on-demand cloud processing with other …

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 …