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Full-Text Articles in Earth Sciences

Pore Morphometrics And Thermal Evolution Of Organic-Matter Microporosity, Colorado Group, Western Canada Foreland Basin, Peng Jiang Dec 2013

Pore Morphometrics And Thermal Evolution Of Organic-Matter Microporosity, Colorado Group, Western Canada Foreland Basin, Peng Jiang

Electronic Thesis and Dissertation Repository

Pores that develop within kerogen particles make a significant contribution to the network flow capacity and hydrocarbon storage of carbonaceous mudstone reservoirs. It has been suggested that development of Organic matter pores results from thermal degradation of kerogen. The range of thermal and subsidence histories of strata in the Western Canada Foreland Basin provide an excellent framework in which to evaluate the influence of thermal maturity on organic matter micropore morphometrics, and the opportunity to evaluate clay microfabric characteristics. Imaging and pore characterization of mudstone samples from the Upper Cretaceous (Cenomanian-Turonian) Colorado Group of the WCFB has been conducted using …


Mitigating Permafrost Degradation Due To Linear Disturbances In Sub-Arctic Peatlands, Aaron A. Mohammed Dec 2013

Mitigating Permafrost Degradation Due To Linear Disturbances In Sub-Arctic Peatlands, Aaron A. Mohammed

Electronic Thesis and Dissertation Repository

The presence or absence of permafrost significantly influences the hydrology and ecology of northern watersheds. Linear disturbances resulting from tree canopy removal have led to widespread permafrost degradation in northern peatlands. Seismic lines resulting from oil and gas exploration now account for large portions of the drainage density of sub-arctic basins, and affect the region’s water and energy balances. As these peatlands represent some of the most sensitive ecosystems to climate and human disturbances, the ability to simulate perturbations to natural systems in a controlled lab environment is particularly important. This study presents a method that is able to simulate …


Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi Nov 2013

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 …


Spatial Heterogeneities In A Simple Earthquake Fault Model, Javad Kazemian Nov 2013

Spatial Heterogeneities In A Simple Earthquake Fault Model, Javad Kazemian

Electronic Thesis and Dissertation Repository

Natural earthquake fault systems are composed of a variety of materials with different spatial configurations a complicated, inhomogeneous fault surface. The associated inhomogeneities with their physical properties can result in a variety of spatial and temporal behaviors. As a result, understanding the dynamics of seismic activity in an inhomogeneous environment is fundamental to the investigation of the earthquakes processes.

This study presents the results from an inhomogeneous earthquake fault model based on the Olami-Feder-Christensen (OFC) and Rundle-Jackson-Brown (RJB) cellular automata models with long-range interactions that incorporates a fixed percentage of stronger sites, or ‘asperity cells’, into the lattice. These asperity …


Study On The Surface Chemistry Behavior Of Pyrochlore During Froth Flotation, Saeed Chehreh Chelgani Oct 2013

Study On The Surface Chemistry Behavior Of Pyrochlore During Froth Flotation, Saeed Chehreh Chelgani

Electronic Thesis and Dissertation Repository

Separation of pyrochlore from its associated minerals is typically accomplished by froth flotation. The surface chemistry of pyrochlore is similar to many of its associated non-value minerals. Therefore, understanding the surface chemical properties of the pyrochlore for selective pyrochlore flotation will potentially aid in the design of flotation strategies for optimized recovery. In this study, pyrochlore samples were collected from various points in the flotation scheme at the Niobec plant, Quebec, Canada. The SEM-EDX analysis revealed that pyrochlore from the Niobec deposit occurs as high and low iron varieties, and that recovery favours varieties with a lower Fe content. To …


Potassium Metasomatism At The Polymetallic Nico Deposit, Northwest Territories, Canada, Gregory B. Robinson Oct 2013

Potassium Metasomatism At The Polymetallic Nico Deposit, Northwest Territories, Canada, Gregory B. Robinson

Electronic Thesis and Dissertation Repository

High temperature K-metasomatism pervasively replaced Paleoproterozoic volcanic and metasedimentary rocks at Lou Lake NWT. This replacement developed primarily at the structural interface juxtaposing non-metamorphosed Lou Lake volcanic rocks over Treasure Lake Group metasedimentary rocks. This crustal-scale fault developed coeval with the emplacement of anorogenic magmatism within a post-collision extensional setting. Emplacement of porphyry dykes into the fault breccia coincided with K-metasomatism at peak upper-greenschist to amphibolite-facies thermal conditions.

The K-metasomatism resulted from co-mingling of descending crustal fluids and ascending potassic magmatic fluids along the decollement surface. Pervasive K-metasomatism resulted in complete replacement of precursor rocks by potassium feldspar. The pronounced …


Impact Craters As Habitats For Life: Endolithic Colonization Of Shocked Gneiss From The Haughton Impact Structure, Devon Island, Canada, Alexandra Janine Pontefract Sep 2013

Impact Craters As Habitats For Life: Endolithic Colonization Of Shocked Gneiss From The Haughton Impact Structure, Devon Island, Canada, Alexandra Janine Pontefract

Electronic Thesis and Dissertation Repository

Meteorite impacts are ubiquitous throughout our solar system and are a fundamental geological process on rocky and icy planetary bodies. Though initially detrimental to biology, an impact event can favourably change the availability and habitability of a substrate for endolithic organisms, which are then able to (re)colonize micro-fractures and pore spaces created during the impact. The colonization of rocks by endolithic communities is an advantageous trait, especially in environments such as hot or cold deserts, where temperature shifts, low water availability and high UV indices pose a significant problem. On Mars, similar conditions – albeit, more extreme – prevail. In …


Application Of Differential And Polarimetric Synthetic Aperture Radar (Sar) Interferometry For Studying Natural Hazards, Samira Alipour Sep 2013

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 (Mw=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 …


Stable Isotope Ecology And Human-Animal Interactions In Northern Peru, Paul Szpak Sep 2013

Stable Isotope Ecology And Human-Animal Interactions In Northern Peru, Paul Szpak

Electronic Thesis and Dissertation Repository

This dissertation addresses several issues related to isotopic ecology in northern Peru. The first portion of the dissertation focuses on baseline carbon and nitrogen isotopic variability in plants for comparison with paleodietary data. The second portion applies these data to assess animal management practices (camelids) in the Virú Valley on the north coast of Peru using isotopic analysis of bone collagen and serially sampled hair. A detailed survey of plants from the Moche River Valley region demonstrates significant east-west variation in plant carbon and nitrogen isotopic compositions, following changes in altitude from the Pacific coast to the highlands. A growth …


Allostratigraphy, Sedimentology And Paleogeography Of The Cretaceous Upper Fort St. John Group (Upper Albian-Lower Cenomanian) In Northeastern British Columbia, Piotr Jan Angiel Aug 2013

Allostratigraphy, Sedimentology And Paleogeography Of The Cretaceous Upper Fort St. John Group (Upper Albian-Lower Cenomanian) In Northeastern British Columbia, Piotr Jan Angiel

Electronic Thesis and Dissertation Repository

The upper Albian to lower Cenomanian succession in northeastern British Columbia was deposited in the proximal foredeep and is greatly vertically expanded relative to the more eastern part of the basin. The study interval has a wedge-shaped geometry, and is ~780 m thick in the west and thins dramatically to ~280 metres over a distance of ~170 km. Rapid facies changes result in lithostratigraphic units being strongly diachronous. In order to determine depositional history, the present study subdivided the Upper Fort St. John Group into 16 genetically-related allomembers. The new allostratigraphic correlations established in this thesis combined with previous studies, …


Stochastic Simulation Of Multiple-Station Ground Motions And Its Applications, Taojun Liu Aug 2013

Stochastic Simulation Of Multiple-Station Ground Motions And Its Applications, Taojun Liu

Electronic Thesis and Dissertation Repository

Approaches to simulate single- and multiple-component multiple-station ground motion records with target spatial coherency and spatial correlation structures are developed for scenario events in this study. To develop the approaches, spatial correlation of the Fourier amplitude spectrum for a random orientation and for two orthogonal directions is assessed, and empirical equations are suggested. Moreover, spatial coherency of ground motions for two orthogonal horizontal directions is estimated using actual records from seven seismic events. Empirical coherency function is suggested for the components of records in two orthogonal horizontal directions at single and multiple recording stations. It was also found that the …


New Mineralogical And Geochemical Characterization Of Martian Meteorites: Implications For Habitability And Astrobiological Exploration Of Mars, Jared N. Shivak Aug 2013

New Mineralogical And Geochemical Characterization Of Martian Meteorites: Implications For Habitability And Astrobiological Exploration Of Mars, Jared N. Shivak

Electronic Thesis and Dissertation Repository

Mars is thought to have shared many similarities with the Earth during its history, leading to extensive research into the potential for life to arise on Mars. Here, a thorough mineralogical and geochemical characterization of primary and secondary phases in Martian meteorites Los Angeles, Zagami, and Nakhla was performed. This novel approach assesses their potential to host life and build on previous studies that focused on either astrobiological or geological factors. These meteorites were found to contain abundant iron-rich phases that can act as microbial substrates. Investigation of alteration phases in Nakhla allowed for the identification of a new secondary …


Microbially Induced Magnesium Carbonation Reactions As A Strategy For Carbon Sequestration In Ultramafic Mine Tailings, Jenine Mccutcheon Jun 2013

Microbially Induced Magnesium Carbonation Reactions As A Strategy For Carbon Sequestration In Ultramafic Mine Tailings, Jenine Mccutcheon

Electronic Thesis and Dissertation Repository

The atmospheric carbon dioxide (CO2) concentration has increased due to anthropogenic fossil fuel combustion, causing higher global temperatures and other negative environmental effects. CO2 sequestration through carbonate mineralisation provides a stable, long term carbon sink. A natural hydromagnesite playa (Atlin, British Columbia, Canada) demonstrates the ability of phototrophic microorganisms to accelerate magnesium carbonate mineralisation. The site’s biogeochemistry was modeled in a 10 m flow-through bioreactor carbonation experiment, allowing for hydromagnesite precipitation conditions to be refined. Ultramafic mine tailings are a target substrate for carbonation reactions due to their high magnesium content. A synthetic mine leach water, designed …


The Biogeochemical Cycling Of Gold Under Surface And Near-Surface Environmental Conditions, Jeremiah P. Shuster Jun 2013

The Biogeochemical Cycling Of Gold Under Surface And Near-Surface Environmental Conditions, Jeremiah P. Shuster

Electronic Thesis and Dissertation Repository

The mobility of gold at near-surface environmental conditions, e.g., supergene weathering environments, lateritic weathering systems, saline to hypersaline systems and placer gold environments, takes place as oxidised, soluble gold complexes and as reduced elemental gold. The transformation between aqueous and solid states of gold is attributed to the varying geochemical conditions that occur in dynamic environments that are catalysed in part by the biosphere. The primary focus of this research is the investigation of biogeochemical processes that contribute to the cycling of gold using laboratory models to represent various natural systems including chemolithotrophic bacteria, e.g., iron-oxidising bacteria, and heterotrophic sulphate-reducing …


Origins Of Stable Isotopic Variations In Late Pleistocene Horse Enamel And Bone From Alberta, Nicolle S. Bellissimo May 2013

Origins Of Stable Isotopic Variations In Late Pleistocene Horse Enamel And Bone From Alberta, Nicolle S. Bellissimo

Electronic Thesis and Dissertation Repository

Oxygen and carbon isotopic measurements of coevally formed bone and tooth enamel bioapatite from a modern equid show that these tissues record drinking water and diet isotopic signals in an identical fashion. Hence, data for both tissues can be combined to track movement, dietary changes, and seasonal variability over the animal’s lifetime, and climatic variability over longer time periods. This tool was tested for horses using ten paired tooth and bone samples to reconstruct conditions in Alberta during the Late Pleistocene. While post-mortem isotopic alteration confounded interpretation of the results, two key findings emerged: (i) pre- and post-Last Glacial Maximum …


Mapping And Zircon Geochronology Of The Lyon Inlet Boundary Zone, Nunavut; A Crustal Scale Break In The Churchill Province, Nikolas B. Ganderton Apr 2013

Mapping And Zircon Geochronology Of The Lyon Inlet Boundary Zone, Nunavut; A Crustal Scale Break In The Churchill Province, Nikolas B. Ganderton

Electronic Thesis and Dissertation Repository

An important aspect of geology is the understanding of processes that created and modified continents and their resources. Knowledge of the age of formation and metamorphism of crystalline crust is thus important, and has been pursued in a recently discovered crustal-scale boundary on the southern Melville Peninsula (Nunavut, Canada) through field mapping, U-Pb zircon geochronology and electron beam analysis. This >250km-long crustal feature is termed here the Lyon Inlet Boundary Zone (LIBZ). Three samples from a 15 by 20 km map area reveal a complex Archean history with the dominant granitoid unit crystallizing at 2770±38 Ma and metamorphosed at 2670±36 …


The Trentonian (Late Ordovician) Brachiopod Fauna Of Ontario: Evolution Through A Global Warming Event, Akbar Sohrabi Hashjin Apr 2013

The Trentonian (Late Ordovician) Brachiopod Fauna Of Ontario: Evolution Through A Global Warming Event, Akbar Sohrabi Hashjin

Electronic Thesis and Dissertation Repository

This thesis, which examines the evolution of the Late Ordovician (early Katian) brachiopod fauna of Ontario, consists of two main parts: 1) a case study of the Late Ordovician RhynchotremaHiscobeccus lineage of North America to investigate the morphological variations and evolutionary trends of brachiopod fauna in time and space, 2) the paleobiogeography of early Katian brachiopod fauna to explore their distribution patterns at a global scale and controlling factors.

During the Katian, the North American craton experienced a first-order marine transgression. The early stage of this event in the early Katian (Trentonian, Chatfieldian) was marked by the development …


A Multispectral Assessment Of Complex Impact Craters On The Lunar Farside, Bhairavi Shankar Feb 2013

A Multispectral Assessment Of Complex Impact Craters On The Lunar Farside, Bhairavi Shankar

Electronic Thesis and Dissertation Repository

Hypervelocity collisions of asteroids onto planetary bodies have catastrophic effects on the target rocks through the process of shock metamorphism. The resulting features, impact craters, are circular depressions with a sharp rim surrounded by an ejecta blanket of variably shocked rocks. With increasing impact energy, the inner crater cavity can preserve complex morphologies including terraced walls, central uplifts, and melted rocks. The lack of erosion due to the absence of water or an atmosphere makes the Moon the perfect target to study impact crater processes, in particular the distribution of highly shocked materials within impact craters of different sizes. …


The Periglacial Landscape Of Utopia Planitia; Geologic Evidence For Recent Climate Change On Mars., Mary C. Kerrigan Jan 2013

The Periglacial Landscape Of Utopia Planitia; Geologic Evidence For Recent Climate Change On Mars., Mary C. Kerrigan

Electronic Thesis and Dissertation Repository

The northern plains of Utopia Planitia, Mars, hosts an abundance of potential periglacial landforms including scalloped depressions, gullies, and polygon networks. This research was undertaken to investigate the distribution and stratigraphy of scalloped depressions in Utopia Planitia and to reconstruct the past environment in which this periglacial landscape formed. To that end, a revised geologic map of the region has been produced. We define, for the first time, a new Periglacial Unit, the youngest geologic unit in Utopia Planitia. We have also developed a model for the formation and evolution of the periglacial landscape examined by assessing the use of …