Other Earth Sciences Commons^™

The Fate Of Carbonate Rocks During Hypervelocity Impacts: Case Studies From Three Impact Structures On Earth, Nicolas D. Garroni

Electronic Thesis and Dissertation Repository

Approximately 28% of all hypervelocity impact structures discovered on Earth exist in a carbonate-dominated target sequence. Despite decades of research, how carbonate rocks and minerals react to shock metamorphism is still poorly understood. In this contribution, three impact structures on Earth were studied to determine the effects of shock metamorphism on carbonate minerals: Chicxulub, Crooked Creek and Jebel Waqf as Suwwan.

At Chicxulub, carbonates from the impact-melt bearing breccia of drill core, M0077A were characterized petrographically and geochemically. Calcite was the only carbonate mineral present and is abundant throughout the impact breccia in five distinct varieties: limestone clasts …

Complex Unicellular Microfossils From The 1.9 Ga Gunflint Chert, Canada, Ana L. González Flores

Electronic Thesis and Dissertation Repository

The presence of eukaryotic life during the early Paleoproterozoic has been a matter of debate because well-preserved fossils older than 1.8 Ga rarely exhibit eukaryotic cellular microstructures. In this study, microfossils from the 1.9 Ga Gunflint Chert were studied using the extended-focal-depth imaging technique, combined with scanning electron microscopy, resulting in recognition of three types of large (10–35 μm diameter) complex unicellular bodies (CUBs) and one type of “multicellular body” (< 50 μm diameter). The CUBs show the following eukaryotic cyst-like structures: (1) radially arranged internal strands similar to those in some acritarchs and dinoflagellates; (2) regularly spaced long tubular processes, stubby pustules, and/or robust podia on the cell surface; (3) reticulate cell-wall sculpturing such as pits, ridges, and scale-like ornaments; and (4) internal bodies that may represent membrane-bounded organelles. These morphological features provide strong evidence for the presence of protists in the late Paleoproterozoic.

Among the three types of CUBs from the Gunflint microbiota, a new species, Germinosphaera gunflinta sp. nov., was recognized. This species has the diagnostic characteristics of Germinosphaera, such …

Oxygen Speciation In Potassium Silicate And Potassium Aluminosilicate Glasses: Insights From X-Ray Photoelectron Spectroscopy, Ryan Sawyer

Electronic Thesis and Dissertation Repository

In a geological context, glasses are useful analogues for silicate melts as they are more readily studied in the laboratory using a wide range of techniques that are impractical for molten liquids. Understanding the structure of binary silicate glasses can help us understand more about the magmatic processes that affect terrestrial planetary bodies.

Potassium silicate glasses ranging in composition from 10 mol% to 35 mol% K₂O were studied using X-ray Photoelectron Spectroscopy (XPS). From high resolution O 1s XPS spectra, Bridging Oxygen (BO) mole fractions were calculated and compared with those of previous ²⁹Si MAS NMR studies. …

Investigation Of Sulphide-Poor Gold Mineralization At The Deep A Zone, Kiena Complex, Québec, Stephanie A. Kobylinski

Electronic Thesis and Dissertation Repository

The Kiena Complex is located halfway between Malartic and Val d’Or in Québec, within the Abitibi Greenstone belt in the Superior Province. This study examined mineralization at the Kiena Complex using detailed core logging, geochemical analysis of wall rock, petrography, EPMA, and gold deportment studies. The analysis and interpretations indicate that the unique sulphide-poor gold-rich quartz veins of the Deep A Zone at the Kiena Complex contain 500 μm²) are located at the contact of quartz and corroded albite grains, and fine gold grains (5-500 μm²) are hosted within the corroded albite.

Stochastic Source Modelling And Tsunami Analysis Of The 2012 Mw 7.8 Haida Gwaii Earthquake, Karina Martinez Alcala

Electronic Thesis and Dissertation Repository

The Mw 7.8 2012 Haida Gwaii Earthquake triggered a tsunami that highlighted the importance of tsunami hazard assessment on Canada’s Pacific coast. Stochastic source modelling serves as a valuable method to assess future tsunami hazard and has not been performed for this region. The source models characterize the uncertainty of earthquake ruptures by considering variability in fault geometry and slip heterogeneity, which, in turn, allows the consideration of a wide range of tsunami scenarios in the Haida Gwaii region. The model predictions are constrained by observational data and past source inversion studies. One hundred twenty-eight stochastic tsunami scenarios are generated …

The Physical Properties Of Volcanic And Impact Melt, Gavin Douglas Tolometti

Electronic Thesis and Dissertation Repository

The emplacement mechanisms of lunar impact melt flows, that form from hypervelocity impact events, have been a subject of debate in the lunar science community, because of their unique physical properties that separate them from other geologic features. Understanding how lunar impact melt flows were emplaced on the surface of the Moon will not only grant us new information about the flow dynamics of impact melt but provide insight into the production and distribution of impact melt and how it built and modified the surfaces of planetary surfaces.

Lunar impact melt flows exhibit surface roughness textures and morphologies that are …

An Investigation Of The Adsorption Mechanism Of An Aliphatic Nitrile (Tecflote S11) On Sulphide Mineral Surfaces., Trevor Holness

Electronic Thesis and Dissertation Repository

As grades of new base metal deposits decline and environmental restrictions on their extraction, increase, the mining industry is looking for new methods of processing minerals. This thesis, investigates the manner in which an aliphatic nitrile (TECFLOTE S11) is adsorbed onto the surface of sulphide mineral surfaces, to understand how TECFLOTE S11 can improve the extraction of base metals from their ores.

Bench tests, including micro-flotation, were conducted and their products examined by Time of Flight – Secondary Ion Mass Spectrometry (ToF-SIMS) to establish where the TECFLOTE S11 was adsorbed onto the mineral surface. The tests showed that the adsorption …

Hargraves Crater Ejecta And Implications For Impact Processes, Leah E. Sacks

Electronic Thesis and Dissertation Repository

Impact craters and their ejecta deposits offer insights into the structure and composition of planet crusts. Hargraves Crater, Mars, demonstrates an unusual balance of exposure and preservation in its ejecta. Analysing its morphologic, morphometric, thermophysical, and stratigraphic characteristics, we interpret two predominant units: an underlying ballistic lithic breccia and an overlying impact melt-bearing deposit. The lower unit is a lithic breccia composed of sub-angular, unsorted clasts (~10-12 m mean diameter), while the overlying unit is a smooth, dark toned, smaller clast-bearing (~1 m diameter at image resolution) impact melt-bearing unit with polygonal fracturing. There appears to be a sharp contact …

Physical Dispersions Of Meteor Showers Through High Precision Optical Observations, Denis Vida

Electronic Thesis and Dissertation Repository

Meteoroids ejected from comets form meteoroid streams which disperse over time due to gravitational perturbations and non-gravitational forces. When stream meteoroids collide with the Earth's atmosphere, they are visible as meteors emanating from a common point-like area (radiant) in the sky. Measuring the size of meteor shower radiant areas can provide insight into stream formation and age. The tight radiant dispersion of young streams are difficult to determine due to measurement error, but if successfully measured, the dispersion could be used to constrain meteoroid ejection velocities from their parent comets. The estimated ejection velocity is an uncertain, model-dependent value with …

Characterization Of Impactite Clay Minerals With Implications For Mars Geologic Context And Mars Sample Return, Christy M. Caudill

Electronic Thesis and Dissertation Repository

Geological processes, including impact cratering, are fundamental throughout rocky bodies in the solar system. Studies of terrestrial impact structures, like the Ries impact structure, Germany, have informed on impact cratering processes – e.g., early hot, hydrous degassing, autometamorphism, and recrystallization/devitrification of impact glass – and products – e.g., impact melt rocks and breccias comprised of clay minerals. Yet, clay minerals of authigenic impact origin remain understudied and their formation processes poorly-understood. This thesis details the characterization of impact-generated clay minerals at Ries, showing that compositionally diverse, abundant Al/Fe/Mg smectite clays formed through these processes in thin melt-bearing breccia deposits of …

Rare-Metal Alkaline Granite From The Arabian Shield, Saudi Arabia, Abdullah A. Aseri

Electronic Thesis and Dissertation Repository

Mineral deposits of high field strength elements (HFSE) and rare earth elements (REE) are commonly within granites that have experienced strong post-magmatic alterations. There has been a long debate on whether the mineralization is due to magmatic and/or hydrothermal processes. The Arabian Shield hosts several economical rare-metal alkaline granites that are poorly understood. This work aims to evaluate the nature of the mineralization in three rare-metal granites from the Arabian Shield, showing distinct mineralization styles ranging between disseminated mineralization at Al-Ghurayyah, pegmatite and hematized granite at Jabal Sayid, and quartz veins at Dyaheen.

The granites from all three areas are …

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, …

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 …

Understanding New Trends On Gold Mineralization At The Yellowknife City Gold Project, Northwest Territories, Using Synchrotron X-Ray Spectroscopy, Ramjay Jude L. Botor

Electronic Thesis and Dissertation Repository

The Yellowknife City Gold Project (YCGP) currently encompasses 780 sq. km of contiguous land north, south and east of the city of Yellowknife. The project lies in the prolific Archean north-south trending Yellowknife Greenstone Belt, a suite of mafic and felsic volcanics and greywacke turbidites overlying a gneissic basement. Exploration and drilling efforts have been focused along 70 km of strike length on the southern and northern extensions of the mineralized shear zones and quartz veins associated with the past-producing high-grade Con (6.1 Moz @ 16.1 g/t Au) and Giant (8.1 Moz @ 16.0 g/t Au) gold mines.

Synchrotron X-ray …

The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, Arya Bina

Electronic Thesis and Dissertation Repository

Currently, Mars appears to be in a ‘frozen’ and ‘dry’ state, with the clear majority of the planet’s surface maintaining year-round sub-zero temperatures. However, the discovery of features consistent with landforms found in periglacial environments on Earth, suggests a climate history for Mars that may have involved freeze and thaw cycles. Such landforms include hummocky, polygonised, scalloped, and pitted terrains, as well as ice-rich deposits and gullies, along the mid- to high-latitude bands, typically with no lower than 20o N/S. The detection of near-surface and surface ice via the Phoenix lander, excavation of ice via recent impact cratering activity as …

Characterization Of Kelyphite Rims: Relevance To Diamond Exploration, Mallory N.G. Metcalf

Electronic Thesis and Dissertation Repository

A detailed investigation into the mineralogy and chemistry of kelyphitic rims/veins on garnets was conducted using µXRD, EPMA and Raman spectroscopy for a suite of samples from economic and non-economic kimberlites in Canada and South Africa. Mineralogy demonstrates the influence of metasomatic fluids during the reactions which produced kelyphite in all localities and was used to propose P-T regions where kelyphite could have formed. Using chemical analyses of host garnets and the mineralogy obtained for kelyphite, modified chemical reactions representing Types 1 and 2 kelyphite are provided to describe kelyphite reactions in open systems. Elastically-strained secondary garnet is common in …

Ordovician Continental Paleogeography And Paleoenvironment For The Michigan Basin From Paleomagnetic Analysis, Michelle Macrae

Electronic Thesis and Dissertation Repository

This study investigates the paleomagnetic record of Paleozoic rocks from two Michigan basin localities in southwestern Ontario to help close the 40 myr gap in Paleozoic paleomagnetic data. Paleomagnetic data from the Queenston (Upper Ordovician) formation consistently exhibits easily removed viscous remanence, an intermediate and a high temperature component consistent with the unblocking temperatures of magnetite and hematite respectively. Alternating-field and thermal demagnetization in 16–20 steps up to 670º C typically reveal a southeastern, shallow up direction removed from magnetite, and a southwestern, steep up direction removed from hematite. A Late Paleozoic overprint was preserved in the magnetite and a …

The Sudbury Impact Structure - New Insights Into The Origin And Emplacement Of The Basal Onaping Intrusion And The Parkin, Trill And Foy Offset Dykes Of The North Range, Denise Anders

Electronic Thesis and Dissertation Repository

The 1.85 Ga Sudbury impact structure is considered a remnant of a multi-ring basin with an estimated original diameter of 150-200 km. The so-called “Basal Onaping Intrusion” form discontinuous sheets between the Granophyre of the Sudbury Igneous Complex (SIC) and the Sandcherry Member of the Onaping Formation and had been considered part of the complex breccia series of the Onaping Formation. Based on the investigation of core and field samples from the North Range we conclude that the Basal Onaping Intrusion, in fact, are the roof rocks of the SIC and, thus, may represent the initial bulk composition of the …

Emplacement Of The Foy, Hess And Pele Offset Dykes At The Sudbury Impact Structure, Canada, Eric A. Pilles

Electronic Thesis and Dissertation Repository

The 1.85 Ga Sudbury impact structure is the remnant of what is generally considered to have been an ~150–200 km diameter impact basin in central Ontario, Canada. The so-called Offset Dykes are impact melt dykes that are found concentrically around – and extending radially outward from – the Sudbury Igneous Complex (SIC), a ~3 km thick differentiated impact melt sheet. The dykes are typically composed of two main phases of granodiorite: an inclusion- and sulfide-rich granodiorite in the centre of the dyke, and an inclusion- and sulfide-poor granodiorite along the margins of the dyke. This study uses a combination of …

Inter- And Intra-Annual C And N Isotopic Variability Of C3 And C4 Grasses In A Temperate-Humid Dune Environment, Roshni R. Patel

Electronic Thesis and Dissertation Repository

Seasonal and annual variations in foliar δ¹³C and δ¹⁵N of a C₃ grass Ammophila breviligulata and a C₄ grass Calamovilfa longifolia from the sand dunes of Pinery Provincial Park in southern Ontario, Canada were investigated to assess isotopic variability at a single site within a temperate-humid climatic zone. This work quantifies seasonal δ¹³C and δ¹⁵N variation, tests for correlation of δ¹³C and δ¹⁵N with weather parameters, and evaluates the isotopic responses of these grasses to location within the dune system. Throughout the 2014 growing season, there …

Exploration Of Spatial And Temporal Changes In Trophic Status Of Lakes In The Northern Temporal Forest Biome Using Remote Sensing, Aleksey Paltsev

Electronic Thesis and Dissertation Repository

There is a critical need for detailed surveys of lakes covering large spatial (>100 km²) and temporal scales (decades) to determine if there is an increase in the magnitude and frequency of phytoplankton blooms. Remote sensing was used to: (1) develop a regression model that relates chlorophyll a (chl-a) as a proxy of lake phytoplankton biomass to Landsat TM and ETM+ optical reflectance (r²=0.85, p

Morphological And Structural Mapping Of The Oudemans Impact Crater Layered Central Uplift, Mars, Bahareh Kasmai

Electronic Thesis and Dissertation Repository

Central uplifts in large meteorite impact craters provide valuable information about the subsurface geology of planetary bodies. Compared to impact craters on Earth, Martian central uplifts can be well exposed and can be mapped in detail by using satellite imagery. Central uplifts preserve morphological and structural features formed as result of the combination of emplacement during the impact process, post impact modification, and erosion over time. In this study, the Oudemans Crater central uplift (the largest central uplift with layers on Mars) was investigated. Oudemans (9.89 S, 268.1 E) is 124 km in diameter and is located in the Sinai …

Automated Image Interpretation For Science Autonomy In Robotic Planetary Exploration, Raymond Francis

Electronic Thesis and Dissertation Repository

Advances in the capabilities of robotic planetary exploration missions have increased the wealth of scientific data they produce, presenting challenges for mission science and operations imposed by the limits of interplanetary radio communications. These data budget pressures can be relieved by increased robotic autonomy, both for onboard operations tasks and for decision- making in response to science data.

This thesis presents new techniques in automated image interpretation for natural scenes of relevance to planetary science and exploration, and elaborates autonomy scenarios under which they could be used to extend the reach and performance of exploration missions on planetary surfaces.

Two …

Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi

Electronic Thesis and Dissertation Repository

Assessment of the current approach taken by guidelines and design methods of vertical closed loop heat exchangers shows that often groundwater flow is either disregarded or is not methodically incorporated. The state of scientific research in this arena reveals that overlooking the groundwater flow in the design procedure may not always be a correct assumption. The significance of advective heat transport compared to conduction is defined by the groundwater flux or Darcy velocity which heavily depends on the hydraulic conductivity of the ground, followed by the hydraulic gradient which has a relatively limited range. A sensitivity analysis on ground and …

Application Of Differential And Polarimetric Synthetic Aperture Radar (Sar) Interferometry For Studying Natural Hazards, Samira Alipour

Electronic Thesis and Dissertation Repository

In the following work, I address the problem of coherence loss in standard Differential Interferometric SAR (DInSAR) processing, which can result in incomplete or poor quality deformation measurements in some areas. I incorporate polarimetric information with DInSAR in a technique called Polarimetric SAR Interferometry (PolInSAR) in order to acquire more accurate and detailed maps of surface deformation.

In Chapter 2, I present a standard DInSAR study of the Ahar double earthquakes (M_w=6.4 and 6.2) which occurred in northwest Iran, August 11, 2012. The DInSAR coseismic deformation map was affected by decorrelation noise. Despite this, I employed an advanced …

Crystal Structure And Al/Si Cation Ordering In "Fassaite": A Combined Single Crystal, 27al And 29si Nmr Study, Monika M. Haring

Electronic Thesis and Dissertation Repository

Al-,Ti-rich diopside, referred to herein as fassaite, occurs in both terrestrial and extraterrestrial environments. The composition of fassaite, Ca(Mg,Al)(Si,Al)₂O₆, makes it ideal for Al/Si cation ordering studies. In this study, crystal XRD, ²⁷Al and 29Si MAS NMR as well as ²⁷Al 3QMAS NMR is used to study cation ordering in extraterrestrial fassaite from Allende CAIs and a terrestrial analogue from Fassa Valley Italy. From ²⁷Al and ²⁹Si spectroscopy, fassaite from Allende CAIs is found to have more local Al/Si cation ordering than terrestrial Fassaite. Both terrestrial and extraterrestrial have C2/c …

Metallogenic Setting Of High-Grade Iron Ores, Mary River District, North Baffin Island, Nunavut, Meghan E. Macleod

Electronic Thesis and Dissertation Repository

Supracrustals of the 2.76-2.71 Ga Mary River Group form the northeastern segment of the Committee Bay Belt. Field mapping has determined that this succession is preserved in structural keels marginal to high-grade gneiss domes and is characterized by lower metasedimentary rocks and an upper BIF-komatiite-quartzite succession. Algoma-type BIF sited at the dome/keel boundary is host to bodies of high-grade iron ore, the largest being Deposit 1 which has an estimated reserve of 500 mt averaging 64 wt % Fe.

Field mapping, petrography, and EMPA indicates 3 main stages of ore formation. Stage 1 was characterized by the formation of the …

Impact Of Geomagnetically Induced Currents On Power Transformers, Jonathan E. Berge

Electronic Thesis and Dissertation Repository

This thesis deals with the impact of Geomagnetically Induced Current (GIC) on power transformers in electrical power systems. A simulator to calculate the flows of GIC in an electrical power network, based on an assumed or measured induced geoelectric potential is proposed. This simulator includes all needed mapping techniques to handle a system that cover a large geographical area.

A correlation between GIC and the reactive power absorbed in the core of the saturated transformer is proposed. That correlation is used to estimate GIC in a transformer utilizing existing reactive power measuring infrastructure within the electrical grid without the need …