Among the deadliest of explosive volcanic hazards are pyroclastic surges – fast-moving, hot, dilute ground-hugging currents that overtop topography and leave complex deposits. Understanding the link between surge dynamics and their deposits is crucial for forecasting the impacts of future eruptions. To investigate surges, two sets of scaled laboratory experiments were conducted. Set 1 released fluid pulses into less-dense ambient water (3-m flume). Pulse fluids were saline solutions with and without particles, and alcohol-water-particle mixtures. Non-dimensional numbers are calculated using both input parameters and measured outcomes. Inputs - fluid density, particle size and concentration, and volume of fluid released - were varied to explore a range of conditions. Key output parameters obtained by video analysis are flow thickness and propagation velocity. Propagation velocity, Re, and Ri increased with increasing pulse density, while Pn decreased. Lab Re values indicate fully turbulent flows, consistent with natural flows. Lab Ri closely matched nature and flow propagation was largely controlled by negative buoyancy, with entrainment playing a minor role. All flows began as subcritical (Fr<1). Alcohol-water-particle runs exhibited buoyancy reversals caused by particle sedimentation, characterized by gradual deceleration and late-stage formation of buoyant plumes. Saline runs maintained nearly constant velocities. In the second set of experiments, alcohol-water-particle mixtures were pulsed over particle bed. Various substrate topographies were tested (flat, mound-trough sequences, steps, wedges). Deposits thickened in troughs and thinned on peaks. Progressive climbing dunes formed on the lee side of the second peak of double peaks and peak-trough combinations, and in step-up topographies. Regressive climbing dunes formed on the stoss side of the first peak of peak-trough combinations and step-down topographies, and on the stoss side of mounds. Climb angles were 16 to 36°, consistent with those documented in pyroclastic surge deposits. The occurrence of both regressive and progressive climbing dunes suggests localized transitions between subcritical and supercritical flow. No cross-beds formed on flat substrates, suggesting that complex substrate topography is required for bedforms to occur in nature. A code benchmarking effort is underway in which targeted model runs will be compared to both sets of experiments in order to develop comprehensive hazards prediction tool.

Space weathering of planetary surfaces is a complex process involving many mechanisms that work independently over different timescales. This research aims to address outstanding questions related to solar wind rim formation on space weathered regolith and tests a new hypothesis that dielectric breakdown plays an important role in the optical maturation of lunar regolith. The purpose of this work is to highlight the limitations imposed by laboratory equipment to accurately simulate the solar wind’s effects on regolith and to provide physical context for the possible contributions of dielectric breakdown to space weathering. Terrestrial and lunar samples were experimentally irradiated and damage was characterized using electron microscopy techniques. Low-fluence proton irradiation produced differential weathering in a lunar mare basalt, with radiation damage on some phases being inconsistent with that found in the natural lunar environment. Dielectric breakdown of silicates revealed two electrical processes that produce characteristic surface and subsurface damage, in addition to amorphous rims. The results of this research highlight experimental parameters that if ignored, can significantly affect the results and interpretations of simulated solar wind weathering, and provides a framework for advancing space weathering research through experimental studies.

This combined research provides in-depth insights into both the tectonic evolution of the Bradshaw Mountain region in Arizona and the effective use of Structure-from-Motion (SfM) photogrammetry in remote geological education. The first study focuses on deciphering paleostress fields in the Bradshaw Mountains region, which helps unravel Earth's past tectonic activities and lithospheric evolution. By examining fractures in plutonic stocks, ranging in age from 73 to 64 million years, crucial insights into the area's tectonic history were obtained. Fracture properties such as size, frequency, orientation, and location were diligently recorded. Further examination in a regional context revealed a complex stress regime during the Laramide orogeny, underpinned by diverse fracture and aplite dike orientations. The findings hint at potential influences of stress reversal during Laramide pluton emplacement and crystallization on regional principal stress, which deviated from previous regional tectonic studies. Factors like crustal dilation, local uplift, tensile stress cycle, and topographic stress could explain the lack of predicted mineralized orientations. The implications of these findings are vital for reconstructing Laramide tectonic and magmatic activities in the region, although further research is required to fully understand the causative mechanisms. The second study centers on the use of SfM photogrammetry in geological education, with a focus on remote learning environments. This involves creating 3D models of hand samples and outcrops with exceptional resolution for detail recognition. Detailed guidance on hardware and software specifications, image capture conditions, file management, and 3D model creation using Metashape is provided. The study emphasizes the dual-masking technique for optimum texture quality and the role of SketchFab in the analysis and viewing of the final product. This integration of SfM photogrammetry into geological education supplements traditional hands-on learning and enhances students' grasp of geological concepts. The technique provides an immersive, interactive experience, especially beneficial for students unable to physically access geological samples, and fosters critical thinking through a hands-on digital interface.

The Pennsylvanian and Permian sedimentary units of the American Southwest hold valuable records of a significant major tectonic event that formed the Ancestral Rocky Mountains and associated basins, such as the Paradox and Pedregosa Basins. These mountains exposed Precambrian crystalline rocks, contributing debris into the basins, forming predominantly reddish sedimentary sequences, such as the Supai Group of Grand Canyon, and the Abo Formation and Yeso Group of New Mexico. Previous studies have indicated that components of these sedimentary sequences were derived from regions outside the Southwest, such as the Appalachian Mountains of that time.Central New Mexico contains well-exposed sequences of Pennsylvanian and Permian sedimentary units with extensively studied biostratigraphy. Tight palaeontologic age constraints from these sequences provide an opportunity to examine variations over time of the relative contribution of sediment derived from the nearby Ancestral Rocky Mountains versus sediment of more distal origins. This study utilizes the laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) approach to U-Pb dating of detrital zircons found within the Pennsylvanian and Permian sequences of central New Mexico, to evaluate changes in potential source regions and sediment transport over time, and to contribute insights to the existing tectonic and sedimentary record of the area during the Pennsylvanian and Permian periods. The findings reveal the Pennsylvanian units were dominated by locally derived sediment, characterized by zircon ages ranging from 1400 to 1800 Ma, whereas Permian units record a substantial influx of distally derived grains with zircon ages ranging from approximately ~270 Ma to 1300 Ma. This indicates that the Ancestral Rockies were the dominant sedimentary sources during the Pennsylvanian but became subdued enough in the Permian to allow the sedimentary basins to capture exotic grains derived from distant regions in North America. These findings contribute valuable insights to the tectonic and sedimentary history of central New Mexico during the Pennsylvanian and Permian periods, shedding light on the evolution of the Ancestral Rockies and the influences of distant sediment sources on the region's depositional patterns.

Identifying space resources is essential to establish an off-Earth human presence on the Moon, Mars, and beyond. One method for determining the composition and mineralogy of planetary surfaces is thermal infrared emission spectroscopy. I investigated this technique as a potential tool to explore for magmatic Ni-Cu±PGE sulfide deposits by producing and measuring a 100% sulfide (pyrrhotite) sample derived from the Stillwater Complex. Pyrrhotite violates key assumptions used to calibrate thermal infrared emission data, making extraterrestrial sulfides “appear colder” than their actual physical temperature, and their spectra will contain a negative slope. To derive the absolute emissivity of graybody minerals more accurately, I developed a new measurement technique, which demonstrates that pyrrhotite is spectrally featureless in the mid-infrared and has a maximum emissivity of ~0.7. Magmatic sulfide deposits are commonly associated with silicates. Thus, emissivity spectra of sulfide/silicate mixtures were acquired to further understand how sulfide prospecting would be conducted on rocky bodies such as Mars. I demonstrate that as sulfide increases, the apparent brightness temperature decreases linearly and, if left unaccounted for, will contribute a negative spectral slope in their emissivity spectra. The presence of sulfide also reduces the magnitude of all the silicate’s diagnostic spectral features, which is linear as sulfide increases. A linear retrieval algorithm was also applied to the mixture spectra, demonstrating that sulfide could be detected at abundances of ≥10 modal %. The main resource being targeted for mining on the Moon is water ice. Thus, a mining map tool of the Lunar South Pole that incorporates temperature, illumination, Earth visibility, and slope data was developed to identify the most suitable locations for water ice mining and establishing bases for operations. The map is also used to assess the mining potential of the Artemis III candidate landing regions. Finally, space mining must be governed, but no framework has yet to be established. I propose a governance structure, notification system, contract system, best mining practices, and area-based environmental regulations to manage water ice mining activities. The Lunar Mining Map Tool’s block system is used as a spatial planning tool to administer the governance framework and facilitate management.

Lithium (Li) is a trace element in kerogen, but the content and isotopic distribution (δ7Li) in kerogen has not previously been quantified. Furthermore, kerogen has been overlooked as a potential source of Li to sedimentary porefluids and buried sediments. Thus, knowing the content and isotopic composition of Li derived from kerogen may have implications for research focused on the Li-isotopes of buried sediments (e.g., evaluating paleoclimate variations using marine carbonates).The objective of this work is to better understand the role of kerogen in the Li geochemical cycle. The research approach consisted of 1) developing reference materials and methodologies to measure the Li-contents and δ7Li of kerogen in-situ by Secondary Ion Mass Spectrometry, 2) surveying the Li-contents and δ7Li of kerogen bearing rocks from different depositional and diagenetic environments and 3) quantifying the Li-content and δ7Li variations in kerogen empirically in a field study and 4) experimentally through hydrous pyrolysis. A survey of δ7Li of coals from depositional basins across the USA showed that thermally immature coals have light δ7Li values (–20 to – 10‰) compared to typical terrestrial materials (> –10‰) and the δ7Li of coal increases with burial temperature suggesting that 6Li is preferentially released from kerogen to porefluids during hydrocarbon generation. A field study was conducted on two Cretaceous coal seams in Colorado (USA) intruded by dikes (mafic and felsic) creating a temperature gradient from the intrusives into the country rock. Results showed that δ7Li values of the unmetamorphosed vitrinite macerals were up to 37‰ lighter than vitrinite macerals and coke within the contact metamorphosed coal. To understand the significance of Li derived from kerogen during burial diagenesis, hydrous pyrolysis experiments of three coals were conducted. Results showed that Li is released from kerogen during hydrocarbon generation and could increase sedimentary porefluid Li-contents up to ~100 mg/L. The δ7Li of coals becomes heavier with increased temperature except where authigenic silicates may compete for the released Li. These results indicate that kerogen is a significant source of isotopically light Li to diagenetic fluids and is an important contributor to the global geochemical cycle.

The American Southwest is one of the most rapidly growing regions of the United States, as are similar arid regions globally. Across these landscapes where surface water is intermittent and variable, groundwater aquifers recharged by surface waters become a keystone resource for communities and are consumed at rates disproportional to recharge. In this study, I focus on the controls of runoff generation and connectivity at both hillslope and watershed scales along a piedmont slope. I also investigate the effects of plant phenology on hydrologic connectivity and runoff response at the hillslope scale during the summer monsoon season. To carry out this work, I combine existing hydrologic instrumentation, a new set of runoff plots with high-resolution monitoring, near-field remote sensing techniques, and historical datasets. Key analyses show that a rainfall intensity (I30) of 10 mm/hr yields runoff production at three scales (8, 12700, and 46700 m2). Rainfall, runoff, and soil moisture observations indicate a Hortonian (infiltration-excess) dominated system with little control imposed by antecedent wetness. Hydrologic connectivity analyses revealed that <15% of total rainfall events generate runoff at the hillslope scale. Of the hillslope events, only 20% of the runoff production leads to discharge at the outlet. Vegetation was observed to effect individual plot runoff response to rainfall. The results of this study show that 1) rainfall intensity is a large control on runoff production at all three scales (8, 12700, and 46700 m2), 2) proportions between bare and vegetated space effect runoff production at the hillslope scale, and 3) runoff connectivity decreases, and channel losses increase as you move downstream on an individual storm basis and across a 30-year historical record. These findings indicate that connectivity from the hillslope to outlet scale can be an evolving process over thehistorical record, reliant on both rainfall intensity, plant and bare soil mosaics, and available channel storage.

The goal of the first study was to characterize the Miocene arkosic conglomerate in the Goldfield Mountains to determine the paleocurrent direction and source of the cobbles. This conglomerate is tilted to the northeast and unconformably overlies Proterozoic basement. Imbrication measurements are scattered but suggest the direction of paleoflow was toward the northwest and northeast, which suggests the cobbles were sourced from the southeast and southwest. The abundance of Dripping Spring Quartzite and the presence of Barnes Conglomerate in the cobbles, suggests an Apache Group source. In addition, south-southeast of the map area, there are several rock units composed of the same material as cobbles within the arkosic conglomerate. The arkosic conglomerate was likely deposited during onset of mid-Cenozoic extension, where the resulting highlands could provide a nearby source for the cobbles. This nearby source is interpreted to be south-southeast of the study area. A second study examined the effectiveness of course reform conducted on an introductory undergraduate course sequence. Questions of this study included: (1) How does the curriculum cater to a student population with diverse goals? (2) How do reformed courses add educational value as perceived by the student? (3) How does the redesigned curriculum and the instructional strategies, as implemented, address the goals of the reform? The curriculum addressed the goals of the reform by (1) creating more opportunities for students to gain the skills relevant to their future goals, (2) having students utilize big data to make observations, interpretations, and predictions, (3) engaging students in scientific collaboration through group work and discussion, (4) giving students the opportunity to utilize computer programs that apply across various subjects and fields (i.e. Excel, MS Word, ArcGIS), and (5) requiring students to conduct original research to solve a problem and present their results orally and in written form. These redesign efforts were successful in meeting the objectives, and majority of the student participants reported one or more of the reformed experiences were valuable to their education and future goals. An understanding of teaching methods and educational values held by undergraduate students within the School of Earth and Space Exploration can be adapted and applied across subjects.

This project produced a dual-medium (traditional screen & virtual reality) virtual environment of Barnhardt Canyon, in Payson, Arizona. The project showcases two different approaches to developing a virtual environment with both being centered by 360 degree content. The virtual environment allows a user to explore the area in a much more immersive way than offered by traditional media. Future uses of the project could include research on the educational efficacy of virtual reality content, or the project could be used as a teaching tool in geoscience classes.