Matching Items (25)
Description
Papago Park in Tempe, Arizona (USA) is host to several buttes composed of landslide breccias. The focus of this thesis is a butte called “Contact Hill,” which is composed of metarhyolitic debris flows, granitic debris flows, and Barnes Butte Breccia. The Barnes Butte Breccia can be broken down into several different compositional categories that can be dated based on their relative ages. The depositional timeline of these rocks is explored through their mineral and physical properties. The rhyolitic debris flow is massively bedded and dips at 26° to the southeast. The granitic debris flow is not bedded and exhibits a mixture of granite clasts of different grain sizes. In thin section analysis, five mineral types were identified: opaque inclusions, white quartz, anhedral and subhedral biotite, yellow stained K-feldspar, and gray plagioclase. It is hypothesized that regional stretching and compression of the crust, accompanied with magmatism, helped bring the metarhyolite and granite to the surface. Domino-like fault blocks caused large brecciation, and collapse of a nearby quartzite and granite mountain helped create the Barnes Butte Breccia: a combination of quartzite, metarhyolite, and granite clasts. Evidence of Papago Park’s ancient terrestrial history is seen in metarhyolite clasts containing sand grains. These geologic events, in addition to erosion, are responsible for Papago Park’s unique appearance today.
ContributorsScheller, Jessica Rose (Author) / Reynolds, Stephen (Thesis director) / Johnson, Julia (Committee member) / School of Earth and Space Exploration (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Hydraulic fracturing, or fracking, has become a common practice in United States oil fields for enhancing their productivity. Among the concerns regarding fracking, however, is the possibility that it could trigger shallow earthquakes. The brine that results from fracking is injected into the subsurface for disposal. This brine causes a pore pressure gradient that is commonly believed to trigger failure along critically stressed subsurface faults. In Timpson, a small city in eastern Texas, earthquakes have become much more common since two injection wells were installed in 2007. 16 events of M_W > 2 have been detected since 2008 and are believed to be associated with failure along a subsurface fault. Applying interferometric synthetic aperture radar, we analyzed 3 sets of SAR images from the Advanced Land Observing Satellite (ALOS) from May 2007 to December 2010. Using these data sets, XX interferograms were generated. From these interferograms, it was possible to determine the spatial and temporal evolution of the crustal deformation in the line-of-sight of the satellite. The results show strong evidence of uplift in the region adjacent to the injection wells. While previous studies have established a strong connection between fluid injection and increased seismicity, this is to our knowledge the first observed case of crustal deformation that has been observed as a result of hydraulic fracturing fluid disposal.
ContributorsSedlak, Alexander Paul Woodward (Author) / Shirzaei, Manoochehr (Thesis director) / Vivoni, Enrique (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Earth and Space Exploration (Contributor)
Created2014-05
Description
Faults found in the arid to semi-arid Basin and Range Physiographic province of the southwestern US are given broad age definitions in terms of which features appear to be the oldest. Particularly in the northwestern corner of Arizona, detailed geomorphic studies on the tectonic history and timing of faulting are not widespread. At the base of the Virgin Mountains in northwestern Arizona is a fault scarp along the Piedmont Fault line. This normal fault crosses a series of alluvial fans that are filled with sediments of ambiguous ages. Previous studies that were done in this region find a broad, Miocene age for the exhumation and uplift of these surfaces, with some indications of Laramide faulting history. However, specific fault characteristics and a time constraint of the tectonic history of the Piedmont Fault scarp has yet to be established. Here, we aim to determine the age, fault-slip rate, seismic history, and potential hazard of the fault scarp near Scenic and Littlefield, Arizona through structure from motion (SfM) modeling, which is a form of photogrammetry using a drone. In addition, we distinguish the climatic and tectonic influences on the geomorphology observed along the scarp through analysis along the fault line. With data collected from a ~500 m section of the fault, we present results from a digital elevation model (DEM) and orthophotos derived through the SfM modelling. Based on field observations and morphologic dating, we determine that the Piedmont Fault experiences an approximately continuous fault-slip and an earthquake recurrence interval in the range of 7,000 years. The approximate age of the scarp is 16.0 ka ± 5 kyr. Therefore, we conclude that the earthquake hazard posed to nearby cities is minimal but not nonexistent. Future work includes further analysis of fault profiles due to uncertainty in the present one and Terrestrial Cosmogenic Nuclide (TCN) dating of samples taken from the tops of boulders in a residual debris flow sitting on faulted and unfaulted alluvia. Determining the ages for these boulder surfaces can hopefully further inform our knowledge of the tectonic activity present in the North Virgin Mountains.
ContributorsApel, Emily Virginia (Author) / Heimsath, Arjun (Thesis director) / Arrowsmith, Ramon (Committee member) / Whipple, Kelin (Committee member) / School of Molecular Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
The mountains of western North America are spectacular and diverse, from sheer walls of crumbling black limestone in the Canadian Rockies, to smooth glacially polished granite in the Wind River Range, to gargantuan ice-clad volcanoes in the Cascades. These great bastions of rock, snow, and ice, still very much wild and untamed, provide an incredible arena for adventure, exploration, and challenge. Over the past three years, I have devoted thousands of hours to exploring these vast wild places, climbing high peaks, steep cliffs, and frozen waterfalls. In doing so, I studied the rich geologic history of the mountains. This thesis project is a compilation of stories and images from those adventures, along with the stories of the mountains themselves: how the rocks were formed, thrust skyward, and sculpted over the ages into their present, glorious form. The photographic and detailed narrative of the geology and adventures is on a new website called Cloud Piercers, which currently features three geologically diverse mountain massifs: (1) Mount Rainier, an active volcano in the Cascade Range of Washington; (2) Mount Robson, the highest peak in the Canadian Rockies, within a terrain of folded Paleozoic sedimentary rocks; and (3) the Wind River Range of Wyoming, composed mostly of Archean metamorphic and granitic rocks. This website will be expanded in the future as the geologic studies and adventures continue.
ContributorsSteadman, Dane Kyle (Author) / Reynolds, Stephen (Thesis director) / Johnson, Julia (Committee member) / Heimsath, Arjun (Committee member) / School of Earth and Space Exploration (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Located in the Sunbelt of the Southwestern United States, Phoenix Arizona finds itself in one of the hottest, driest places in the world. Thankfully, Phoenix has the Salt River, Gila River, Verde River, and a vast aquifer to meet the water demands of the municipal, industrial, and agricultural sectors. However, rampant groundwater pumping and over-allocation of these water supplies based on unprecedented, high flows of the Colorado River have created challenges for water managers to ensure adequate water supply for the future. Combined with the current 17-year drought and the warming and drying projections of climate change, the future of water availability in Phoenix will depend on the strength of water management laws, educating the public, developing a strong sense of community, and using development to manage population and support sustainability. As the prevalence of agriculture declines in and around Phoenix, a substantial amount of water is saved. Instead of storing this saved water, Phoenix is using it to support further development. Despite uncertainty regarding the abundant and continuous availability of Phoenix's water resources, development has hardly slowed and barely shifted directions to support sustainability. Phoenix was made to grow until it legally cannot expand anymore. In order to develop solutions, we must first understand the push for development in water-stressed Phoenix, Arizona.
ContributorsVasquez, Brianna Nicole (Author) / Heimsath, Arjun (Thesis director) / Whipple, Kelin (Committee member) / School of Earth and Space Exploration (Contributor) / School of Art (Contributor) / School of Community Resources and Development (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The tectonism, volcanism, and sedimentation along the East African Rift System (EARS) produced a series of rift basins with a rich paleoanthropological record, including a Late Miocene–present record of hominin evolution. To better understand the relationship between Earth system history and human evolution within the EARS, the Hominin Sites and Paleolakes Drilling Project (HSPDP) collected paleolake sediments near key paleoanthropological sites in Ethiopia and Kenya, compiling a multi-proxy, high-resolution geological and environmental record. As part of the HSPDP, I studied the detrital mineral record of the basins and evaluated tectonic and climatic controls on East African landscapes during the Plio-Pleistocene using samples from three of the drill sites, Chew Bahir: (CHB, ~620–present; Ethiopia), Northern Awash (NA, ~3.3–2.9 Ma; Ethiopia,), and West Turkana (WTK, ~1.9–1.4 Ma; Kenya). I employed laser ablation U/Pb and (U-Th)/He double dating (LADD) of detrital zircons, which yields paired U/Pb and (U-Th)/He dates, and (U-Th)/He dating of detrital apatites to evaluate sediment provenance and the cooling history of the source rocks. In addition, I used in situ 10Be cosmogenic radionuclide analyses to determine paleoerosion rates. Two chapters of this dissertation focus on results from the NA and WTK drill sites. Source units for the NA and WTK drill sites are largely Cenozoic volcanic rocks, and the detrital zircon record yields an extensive record of the timing of various phases of volcanism within the EARS. Exceptionally young zircon (U-Th)/He dates reflect partial resetting associated with late mafic volcanism and/or hydrothermal activity. Erosion rates are consistent and relatively low across the Plio-Pleistocene, despite significant tectonic and geomorphic shifts in the landscape. Two other chapters of this dissertation cover results from the CHB drill site. The Chew Bahir basin has significant exposures of Neoproterozoic and Early Paleozoic crystalline basement units, and the detrital zircon record yields one singular phase of volcanism in the EARS. The CHB erosion rates show an overall decreasing trend over time, consistent with an aridifying climate, and increased environmental variability after ~200 ka.
ContributorsZawacki, Emily Elizabeth (Author) / Arrowsmith, J Ramon (Thesis advisor) / Campisano, Christopher (Thesis advisor) / Heimsath, Arjun (Committee member) / Hodges, Kip (Committee member) / Whipple, Kelin (Committee member) / Arizona State University (Publisher)
Created2021
Description
Mountain landscapes reflect competition between tectonic processes acting to build topography and erosive processes acting to wear it down. In temperate mountain landscapes, bedrock rivers are the primary erosional agent, setting both the pace of landscape evolution and form of the surrounding topography. Theory predicts that river steepness is sensitive to climatic, tectonic, and lithologic factors, which dictate the rates and mechanics of erosional processes. Thus, encoded into topography is an archive of information about forces driving landscape evolution. Decoding this archive, however, is fraught and climate presents a particularly challenging conundrum: despite decades of research describing theoretically how climate should affect topography, unambiguous natural examples from tectonically active landscapes where variations in climate demonstrably influence topography are elusive. In this dissertation, I first present a theoretical framework describing how the spatially varied nature of orographic rainfall patterns, which are ubiquitous features of mountain climates, complicate expectations about how climate should influence river steepness and erosion. I then apply some of these ideas to the northern-central Andes. By analyzing river profiles spanning more than 1500 km across Peru and Bolivia, I show that the regional orographic rainfall pattern this landscape experiences systematically influences fluvial erosional efficiency and thus topography. I also show how common simplifying assumptions built into conventional topographic analysis techniques may introduce biases that undermine detection of climatic signatures in landscapes where climate, tectonics, and lithology all covary – a common condition in mountain landscapes where these techniques are often used. I continue by coupling this analysis with published erosion rates and a new dataset of 25 cosmogenic 10Be catchment average erosion rates. Once the influence of climate is accounted for, functional relationships emerge among channel steepness, erosion rate, and lithology. I then use these functional relationships to produce a calibrated erosion rate map that spans over 300 km of the southern Peruvian Andes. These results demonstrate that accounting for the effects of climate significantly enhances the ability to decode channel steepness patterns. Along with this comes the potential to better understand rates and patterns of tectonic processes, and identify seismic hazards associated with tectonic activity using topography.
ContributorsLeonard, Joel Scott (Author) / Whipple, Kelin (Thesis advisor) / Arrowsmith, Ramon (Committee member) / Christensen, Philip (Committee member) / Forte, Adam (Committee member) / Heimsath, Arjun (Committee member) / Hodges, Kip (Committee member) / Arizona State University (Publisher)
Created2022
Description
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.
ContributorsHurst, Joseph Gregory (Author) / Reynolds, Stephen (Thesis advisor) / Semken, Steven (Committee member) / Johnson, Julia (Committee member) / Arizona State University (Publisher)
Created2023
Description
In-person field education through exploration is fundamental in geoscience, but equal access is limited by time, cost, safety, distance, physical ability, and instructor variability. Technology advances allow students to explore pedagogically rich but inaccessible places through virtual field trips (VFTs). Studies show that VFTs result in significant learning gains and are an effective learning modality. Most research has focused on instructor-generated VFTs disseminated through a top-down model, whereas technological innovations are making user-generated VFTs more practical. This longitudinal, mixed-methods study decentralized the production of VFTs by teaching students and educators to build their own VFTs for place-based education via the proposed Virtual Field Trip Production Process for Place-Based Education. Students and educators produced seven place-based VFTs reviewed by subject-matter experts that are currently being used as digital learning experiences in high school and college settings. Place-based education (PBE) traditionally occurs in actual places, while VFTs convey an actual place virtually and can share the same learning objectives as their in-person counterparts. Sense of place, the combination of meanings and attachments an individual or group ascribes to a given place, is a measurable learning outcome of PBE with cognitive, affective, and behavioral components. Participants were administered the Positive and Negative Affect Schedule (PANAS), Place Attachment Inventory (PAI), and Young’s Place Meaning Survey (YPMS). Regression analysis showed statistically significant increases in positive affect (PA) and statistically significant decreases in negative affect (NA) as well as statistically significant gains in sense of place and content knowledge. In both geology and PBE, drawing is an important tool for learning, teaching, and assessing. Current VFT software environments do not allow users to digitally draw within the platform. This study examined differences in learning outcomes and final grades between students submitting mechanical versus digital drawings, geologic maps, and concept sketches. Regression analysis of the drawing, geologic map, and concept sketch exercises revealed no statistically significant differences between mechanical and digital drawing modalities in both learning outcomes and final grades. Geoscience educators can confidently allow students to submit digital drawings while software programmers and learning designers should consider adding this capability to their VFT platforms.
ContributorsRuberto, Thomas (Author) / Semken, Steve (Thesis advisor) / Anbar, Ariel (Committee member) / Reynolds, Steve (Committee member) / Johnson, Julia (Committee member) / DeVecchio, Duane (Committee member) / Arizona State University (Publisher)
Created2023
Description
Aquifers host the largest accessible freshwater resource in the world. However, groundwater reserves are declining in many places. Often coincident with drought, high extraction rates and inadequate replenishment result in groundwater overdraft and permanent land subsidence. Land subsidence is the cause of aquifer storage capacity reduction, altered topographic gradients which can exacerbate floods, and differential displacement that can lead to earth fissures and infrastructure damage. Improving understanding of the sources and mechanisms driving aquifer deformation is important for resource management planning and hazard mitigation.
Poroelastic theory describes the coupling of differential stress, strain, and pore pressure, which are modulated by material properties. To model these relationships, displacement time series are estimated via satellite interferometry and hydraulic head levels from observation wells provide an in-situ dataset. In combination, the deconstruction and isolation of selected time-frequency components allow for estimating aquifer parameters, including the elastic and inelastic storage coefficients, compaction time constants, and vertical hydraulic conductivity. Together these parameters describe the storage response of an aquifer system to changes in hydraulic head and surface elevation. Understanding aquifer parameters is useful for the ongoing management of groundwater resources.
Case studies in Phoenix and Tucson, Arizona, focus on land subsidence from groundwater withdrawal as well as distinct responses to artificial recharge efforts. In Christchurch, New Zealand, possible changes to aquifer properties due to earthquakes are investigated. In Houston, Texas, flood severity during Hurricane Harvey is linked to subsidence, which modifies base flood elevations and topographic gradients.
Poroelastic theory describes the coupling of differential stress, strain, and pore pressure, which are modulated by material properties. To model these relationships, displacement time series are estimated via satellite interferometry and hydraulic head levels from observation wells provide an in-situ dataset. In combination, the deconstruction and isolation of selected time-frequency components allow for estimating aquifer parameters, including the elastic and inelastic storage coefficients, compaction time constants, and vertical hydraulic conductivity. Together these parameters describe the storage response of an aquifer system to changes in hydraulic head and surface elevation. Understanding aquifer parameters is useful for the ongoing management of groundwater resources.
Case studies in Phoenix and Tucson, Arizona, focus on land subsidence from groundwater withdrawal as well as distinct responses to artificial recharge efforts. In Christchurch, New Zealand, possible changes to aquifer properties due to earthquakes are investigated. In Houston, Texas, flood severity during Hurricane Harvey is linked to subsidence, which modifies base flood elevations and topographic gradients.
ContributorsMiller, Megan Marie (Author) / Shirzaei, Manoochehr (Thesis advisor) / Reynolds, Stephen (Committee member) / Tyburczy, James (Committee member) / Semken, Steven (Committee member) / Werth, Susanna (Committee member) / Arizona State University (Publisher)
Created2018