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Quantification Of Surface Roughness Of Lava Flows On Mars, Carolina Rodriguez Sanchez-Vahamonde

Electronic Thesis and Dissertation Repository

Volcanism has played a significant role throughout Mars’ geologic history. Extensive lava flows are widely spread across Mars’ equatorial region, shaping the surface in a very distinct way. In radar images (at the decimeter scale), these flows are bright, which is a typical characteristic of extremely rough, blocky lavas flows seen on Earth. Although the source of the extreme roughness of Martian lava flows is unknown, their surface roughness parameters can be constrained to 1) gain information about Mars’ interior processes, 2) find appropriate analogues on other planetary bodies, and 3) ideally infer the emplacement style of such lavas. Here, …

Numerical Simulations Of Complex Crater Formation In Layered And Mixed Targets, Ryan Hopkins

Electronic Thesis and Dissertation Repository

Numerical simulations of hypervelocity impact events provide a unique method of analyzing the mechanics that govern impact crater formation. This thesis describes modifications that were made to the impact Simplified Arbitrary Lagrangian Eulerian (iSALE) shock-physics code in order to more accurately simulate meteorite impacts into layered target sequences and details several applications that were investigated using this improved strength model.

Meteorite impacts occur frequently in layered targets but resolving thin layers in the target sequence is computationally expensive and therefore not often considered in numerical simulations. To address this limitation iSALE was modified to include an anisotropic yield criterion and …

Statistical Modeling And Characterization Of Induced Seismicity Within The Western Canada Sedimentary Basin, Sid Kothari

Electronic Thesis and Dissertation Repository

In western Canada, there has been an increase in seismic activity linked to anthropogenic energy-related operations including conventional hydrocarbon production, wastewater fluid injection and more recently hydraulic fracturing (HF). Statistical modeling and characterization of the space, time and magnitude distributions of the seismicity clusters is vital for a better understanding of induced earthquake processes and development of predictive models. In this work, a statistical analysis of the seismicity in the Western Canada Sedimentary Basin was performed across past and present time periods by utilizing a compiled earthquake catalogue for Alberta and eastern British Columbia. Specifically, the frequency-magnitude statistics were analyzed …

The Stability Of Temperate Lakes Under The Changing Climate, Aleksey Paltsev

Electronic Thesis and Dissertation Repository

There is a collective prediction among ecologists that climate change will enhance phytoplankton biomass in temperate lakes. Yet there is noteworthy variation in the structure and regulating functions of lakes to make this statement challengeable and, perhaps, inaccurate. To generate a common understanding on the trophic transition of lakes, I examined the interactive effects of climate change and landscape properties on phytoplankton biomass in 12,644 lakes located in relatively intact forested landscapes. Chlorophyll-a (Chl-a) concentration was used as a proxy for phytoplankton biomass. Chl-a concentration was obtained via analyzing Landsat satellite imagery data over a 28-year period (1984-2011) and using …

Shock Effects Recorded By The U-Pb Radiometric System In Zircons Of Apollo 17 Impact Breccias And By Raman Spectroscopy In Enstatite Meteorites, Bidong Zhang

Electronic Thesis and Dissertation Repository

Impact cratering processes and formations are ubiquitous on the rocky planets within the Solar System. The Earth-Moon system was formed by a massive planetary impact, and numerous impacts afterwards significantly reshaped the topography and lithology of the Moon surface. This dissertation focuses on studying some specific geochemical, geochronological, and geophysical signatures of impact processes preserved in lunar rocks and asteroidal meteorites.

The zircon U-Pb radiometric system is one of the most reliable geochronometers in measuring geological time. Recently, unsupported radiogenic Pb enrichment has been reported to compromise the accuracy and precision of zircon U-Pb geochronometer in terrestrial rocks. In Chapter …

Sm-Nd, Lu-Hf, And Mn-Cr Isotope Geochemistry Of Achondrite Meteorites: Implications For The Formation Reservoirs Of Differentiated Planetesimals, Zhiguo Guo

Electronic Thesis and Dissertation Repository

Accretion and differentiation of planetesimals are critical steps of planetary formation. By studying achondrite meteorites, we can bring further geochemical and chronological constraints on the source and composition of materials and their evolution throughout the protoplanetary disk. Major and trace element analyses for mineral and whole-rock compositions and high-precision isotopic compositions for the short- and long-lived radiochronometers ⁵³Mn-⁵³Cr, ^147,146Sm-^143,142Nd and ¹⁷⁶Lu-¹⁷⁶Hf are reported for two eucrites, two diogenites, and three ungrouped achondrites. Of these, NWA 12338 is a newly classified ungrouped achondrite with an anomalously higher Δ¹⁷O than mean …

Ni And Fe Isotope Fractionation During Weathering And The Formation Of Ni Laterite Ore Deposits In The Philippines, Congxi Zhu

Electronic Thesis and Dissertation Repository

Weathering processes on Ni-rich ultramafic rocks in tropical areas produce laterites that become exploitable for Ni mining. To better understand these processes, samples were collected stratigraphically with water samples from several Ni mines in the Philippines and studied for Ni and Fe isotope compositions. This study found that Ni isotope fractionation takes place during the formation of Ni-enriched minerals (goethite), when light Ni isotopes are preferentially incorporated into new minerals formed, leaving heavy Ni isotopes in groundwater. The Δ⁶⁰Ni_{Limonite-Bedrock} is up to -0.19 ± 0.32‰. Even though Fe is partitioned with redox state change during these reactions, …

The Effect Of Stiffness Anisotropy Of A Glacial Clay On The Behaviour Of A Shallow Wind Turbine Foundation, Jesús A. González-Hurtado

Electronic Thesis and Dissertation Repository

Shallow wind turbine foundations are designed based on investigations of the ultimate, serviceability and fatigue limit states. The serviceability limit state design approaches in particular are based on simple isotropic elastic half-space analyses that ignore coupling between loading directions, and soil non-linearity and elastic anisotropy. Many of the wind farms in Ontario are constructed around the Great Lakes basin and a number of these areas are characterized as stiff clayey glacial tills. It is recognized that many of these glacial materials exhibit some degree of strength, stiffness and fabric anisotropy. This research aimed to characterize the anisotropic geotechnical properties of …

Creating Calibration Curves Using In Situ X-Ray Diffraction To Determine The Shock Pressure Experienced By Clinopyroxene, Laura Jenkins

Electronic Thesis and Dissertation Repository

This work extends on two quantitative methods for evaluating shock metamorphism to include clinopyroxene using X-ray diffraction (XRD). Clinopyroxene samples experimentally shocked to known shock pressures were studied with XRD. Lattice strain (ε) and strain-related mosaicity (SRM) were measured for each sample and plotted against their known shock pressures, creating a ε versus shock pressure calibration curve and an SRM versus shock pressure calibration curve. These calibration curves were applied to three meteorites: Nakhla, Zagami, and ALHA 77005. The SRM calibration curve gave peak shock pressures of 12±8 GPa for Nakhla, 44±8 GPa for Zagami, and 68±8 GPa for ALHA …

Using Stable Isotopes To Understand Survival Versus Extinction Of Late Pleistocene Muskoxen, Stephanie Mabee

Electronic Thesis and Dissertation Repository

This thesis uses stable isotopes to investigate the adaptive advantages of Ovibos moschatus, a muskox, relative to now-extinct Pleistocene megafauna in eastern Beringia (Yukon Territory and Alaska), including another muskox Bootherium bombifrons. Ecological niches were defined for Ovibos and Bootherium using stable carbon and nitrogen isotope compositions of bone collagen. Plant remains trapped in modern Ovibos molars were used to determine the carbon and nitrogen isotope collagen-diet discrimination factors, which were then applied to ancient specimens. Ovibos possessed larger isotopic – and hence ecological – niches than Bootherium across eastern Beringian sites. The larger niche suggests that Ovibos …

Calcium Isotopes In The Saint Agatha Kettle Lake Deposits Of Southern Ontario, Emma-Dawn Ferguson

Electronic Thesis and Dissertation Repository

The St. Agatha kettle lake deposits, ON, Canada, contain a thick section of endogenic marl and coeval shelly fauna. Marl accumulation occurred from ~13,500 to ~8,200 cal yrs BP. This study examines controls on marl and shell δ^44/42Ca, element ratios (Mg, Fe, and Ba), δ¹⁸O, δ¹³C, and ⁸⁷Sr/⁸⁶Sr ratios of marl calcite, shell aragonite, groundwater, and bedrock as proxies for paleolacustrine conditions. Results for Interval A (532.0 to 475.0cm) indicates a cooler, wetter climate, lower primary lake productivity and higher lake levels. Interval B (475.0 to 345.0cm) marks the onset of …

Bed Particle Displacement In A Wandering Gravel-Bed River, Ryan Mcqueen

Electronic Thesis and Dissertation Repository

The primary goal of this thesis was to investigate the influence of channel morphology on individual bed particle path lengths in a wandering gravel bed river, the San Juan River, BC. This was achieved through tracking the transport of sedimentary particles using PIT tags and also capturing changes in channel morphology through repeat topographic surveys over the same three year time period as the tracer tracking. Particle transport tended to remain within the riffle-pool-bar sequence in which they were seeded, with modal path lengths related to areas of deposition along bar margins, especially at the bar apex region. This aligned …

Evaluating Zircon Strain Chronometry Of A Grenville Front Deformation Fabric Through Microstructural Analysis And Quartz Piezometry, Kaitlyn Petkau

Electronic Thesis and Dissertation Repository

Zircon strain chronometry can allow correlation of isotopic ages with microstructural fabrics to place an absolute age on the timing of deformation. However, the general applicability of zircon strain chronometry to problems in regional continental tectonics is still being tested and this study is the first effort to apply the approach to the ~1 Ga (billion year old) Grenville Province of the Precambrian Canadian Shield. Samples were analyzed from the 1747 +6/-5 Ma Wanapitei Complex, a poly-deformed mafic metaplutonic body that preserves fabric evidence for several stages in the tectonic history of the Grenville Front. This study is the first …

Allostratigraphy And Sedimentology Of The Muskiki And Marshybank Members Of The Wapiabi Formation (Upper Cretaceous, Coniacian) In Southwestern Alberta, Canada, Elizabeth Hooper

Electronic Thesis and Dissertation Repository

The marine mudstone-dominated, Muskiki and Marshybank members of the Wapiabi Formation occupy the central foredeep of the Western Canada Foreland Basin. These Coniacian (86.3-89.8 Ma) rocks form a ~100 m thick, overall shallowing-upward depositional succession that records a basin-scale transgressive-regressive event following an early Coniacian lowstand. The strata, deposited on a low-gradient storm- dominated marine ramp, contain numerous well-preserved molluscan fossils and comprise many upward-coarsening successions (5-15 m thick). Detailed correlation integrates biostratigraphic and lithologic data from 14 cores and 13 outcrops into a regional (~45,000 km2) allostratigraphic framework constructed from 1020 wireline logs. This integrated stratigraphy provides a basis …

Microfacies Analysis Of Mudstone In A Freshwater To Marine Transect: Upper Cretaceous Dunvegan And Kaskapau Formations, Western Canada Foreland Basin, Katharin Pavan

Electronic Thesis and Dissertation Repository

In the Cenomanian-Turonian Dunvegan and Kaskapau formations in Alberta and British Columbia, terrestrial, and nearshore to offshore environments can be related temporally and spatially using a well-established allostratigraphic framework. In these varied environments, ten mudstone microfacies were identified, using optical and scanning electron microscopy. Microfacies 1 through 3 were deposited in a freshwater lacustrine environment by hyperpycnal flows, and consist of rippled, structureless, and inverse-to-normally graded thin beds that record turbulent, laminar, and waxing and waning flow. Microfacies 4 and 5 were deposited from turbulent flow in a fluvial environment. Microfacies 6 represents a paleosol that underlies a maximum flooding …

Impact Cratering Processes On The Earth And Moon: Meteorites, Complex Craters, And The Origin Of The Moon, Patrick Hill

Electronic Thesis and Dissertation Repository

This thesis seeks to understand the mechanism of hypervelocity impacts, lunar origin and geology, and stable isotope techniques and its application to lunar material. Three lunar regolith breccias, Dhofar 1673, Dhofar 1983, and Dhofar 1984, were examined. The petrography, mineralogy, isotope chemistry, and bulk chemistry of these meteorites were quantified to investigate their origin. The chemistry of the impact melt rock and bulk chemical analysis suggests sourcing from either the Feldspathic or Outer Feldspathic Highland Terranes. Given the similarities in the meteorites, and the proximal location of each find (within 500 m), this thesis proposes strong evidence for their pairing. …

Characteristics Of Impactites In The Central Uplift Of The Mistastin Lake Impact Structure, Canada, Alaura Singleton

Electronic Thesis and Dissertation Repository

This thesis investigated the nature of parautochthonous and allochthonous impactites found in the erosional remnant of the central uplift of the Mistastin Lake impact structure, central Labrador. This was carried out with the goal of discovering details about the composition and formation conditions of these complex materials. This study involved fieldwork and a range of laboratory techniques. As part of this work, a geological map of Horseshoe Island has been created, and is the most detailed to date. The shock metamorphic features found in the uplifted target rocks have been assessed, and indicate a peak shock level of 5a (35-45 …

Considering A Seismically Active Leech River Valley Fault Zone In Southwestern British Columbia, Jacob J. Kukovica

Electronic Thesis and Dissertation Repository

The transpressional reverse Leech River fault (LRF) extends across the southern tip of Vancouver Island and beneath the city of Victoria, British Columbia, Canada. New paleoseismic studies suggest at least three surface-rupturing earthquakes have exceeded a moment magnitude (M) of 6 within a proposed Leech River Valley Fault Zone (LRVFZ) within the last 9,000 years. We examine the impact of an active LRVFZ to predicted earthquake ground motions for Victoria. In a probabilistic formulation considering the likelihood of all earthquake sources, LRVFZ earthquakes will contribute the most to high-frequency ground motions (≥ 10 Hz) in Victoria. The Canadian …

Sedimentology, Lithostratigraphy And Geochronology Of The Paleoproterozoic Gordon Lake Formation, Huronian Supergroup, Ontario, Canada, Carolyn M. Hill

Electronic Thesis and Dissertation Repository

The Gordon Lake Formation of the Paleoproterozoic Huronian Supergroup is a primarily-siliciclastic succession ranging from 300 to 1100 m thick. Lithostratigraphic and sedimentological analysis of the formation in the Bruce Mines and Flack Lake areas, and Killarney and Lady Evelyn-Smoothwater provincial parks revealed 7 lithofacies, which comprise 3 distinct lithofacies associations. The lithofacies associations are subtidal nearshore, subtidal to shallow shelf, and mixed intertidal flat. Microbially-induced sedimentary structures (MISS) related to microbial mat destruction and decay were recognized in the Flack Lake area. The preserved MISS include sand cracks, mat chips, remnant gas domes, and pyrite patches, and iron laminae. …

The Impact-Generated Hydrothermal System Of The East Clearwater Lake Impact Structure, Quebec, Canada, Derek King

Electronic Thesis and Dissertation Repository

Alteration mineralization at impact craters gives insight into the hydrothermal system generated post-impact. This is the first work to document the alteration mineralization to characterize the East Clearwater impact-generated hydrothermal system. The East Clearwater hydrothermal system in the impact melt rocks and melt-bearing breccias transitions from zeolite-smectite assemblages to chlorite-dominant assemblages with depth. pH evolution of the East Clearwater impact-generated hydrothermal system reflects magmatic-driven hydrothermal systems in granitic rocks. West Clearwater has a different alteration style. Given an impact forms a hydrothermal system, the style of alteration will not only vary dependent on target lithologies (i.e., crystalline, sedimentary, mixed target), …

Thermal Performance And Sustainability Of Borehole Heat Exchangers Within Building Clusters, Ronan Drysdale

Electronic Thesis and Dissertation Repository

Geothermal energy has greatly increased in prevalence over the last 20 years. With many new installations, the desire to introduce geothermal energy into unused urban environments has increased. However the urban environment has a great effect on the subsurface thermal profile, which may significantly influence geothermal systems. To test the effectiveness and efficiency of different geothermal systems in tight building clusters, as well as the effects of the system on the subsurface, a three dimensional finite element model was developed. The model is based on an area of University of Western Ontario campus that has a geothermal system utilizing borehole …