Earth Sciences - Theses, Dissertations, and other Required Graduate Degree Essays

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The Murray dyke swarm and its bearing on Cretaceous magmatism and tectonics in the Canadian Cordillera

Author: 
Date created: 
2020-04-17
Abstract: 

The Murray dyke swarm fed the Spences Bridge Group, part of an Early Cretaceous continental arc overlapping the Intermontane terranes. Dykes are well-exposed in a 2x10 km area and strike to the north in a sheeted morphology, consistent with an extensional stress regime and rapid emplacement at 103.7 Ma, based on 40Ar/39Ar and U-Pb geochronology. Dyke compositions range from mafic to felsic. Dykes correspond to three petrological types unrelated through fractional crystallization, reflecting distinct mantle-derived melts that subsequently evolved to various degrees. Two types were generated by flux-melting above a steep slab; the other reflects infiltration of the arc by intraplate-composition melts generated during slab break-off. Subsequent southwest-verging contraction folded the Spences Bridge Group and inverted its forearc basin to the west, shedding detritus that lapped onto the Group with angular unconformity. This evolution is consistent with accretion of the Insular terranes by east-dipping subduction, triggering orogenesis in the mid-Cretaceous.

Document type: 
Thesis
Supervisor(s): 
Derek Thorkelson
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.

Shoreline geometry and depositional architecture of wave-dominated deltaic successions: Upper McMurray Formation, Central-C Area, Northeast Alberta, Canada

Date created: 
2019-11-18
Abstract: 

To decipher the complex juxtaposition of laterally adjacent depositional environments that occur in the upper member of the McMurray Formation to the Wabiskaw Member, detailed sedimentological and ichnological analyses were undertaken. Thirteen facies and five facies associations are identified. The study interval consists of shallow-water deltaic to embayed shoreface successions, that increase in thickness and marine influence upwards. Allogenic and autogenic flooding surfaces were distinguished based on sedimentological, ichnological, and geophysical properties. Allogenic flooding surfaces were mapped across the study area, to identify the internal stratigraphic architecture of the upper member of the McMurray Formation. The thicknesses of individual deltaic shingles were identified by mapping their bounding autogenic flooding surfaces. Allogenic flooding surfaces were assessed to identify the viability of use as localized supplemental datums. During McMurray deposition the paleoshoreline evolved from an elongated restricted embayment to a less-confined, open embayment with more normal marine processes.

Document type: 
Thesis
File(s): 
Supervisor(s): 
James MacEachern
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.

Modelling wastewater spills and mapping areas most vulnerable to groundwater quality deterioration in northeast British Columbia

Date created: 
2020-04-20
Abstract: 

This study utilized numerical modelling of spills and leaks of natural gas production wastewater into the shallow subsurface to identify areas most vulnerable to groundwater quality deterioration in Northeast British Columbia. Modelling was conducted using the flow and transport code TOUGH2. The models were designed to address three main factors identified from the DRASTIC method for vulnerability assessment: (1) Depth to water, (2) Impact of vadose zone, and (3) Conductivity of the aquifer materials. Models show that dense saline wastewater will migrate further and faster through highly permeable materials. Lower permeability materials attenuate the wastewater migration resulting in smaller plumes with locally higher brine concentrations. A sensitivity analysis reveals that the vadose zone permeability and depth to water table are significant controls on wastewater migration and footprint. Overall, the vulnerability in the region is relatively low, with some exceptions near river valleys, mountainous regions, and areas with shallow water tables.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Dirk Kirste
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.

Sequence stratigraphy and facies analysis of the viking formation in crossfield and adjacent areas, Alberta, Canada

Author: 
Date created: 
2020-03-18
Abstract: 

The Lower Cretaceous Viking Formation is a siliciclastic unit that accumulated in the Western Interior Seaway and produces hydrocarbons in the Crossfield and surrounding area. The study area encompasses Townships 24–31, Ranges 28W4 to 4W5 in Alberta, Canada. Sedimentological and ichnological observations of 54 cored wells, coupled with the analysis of 1415 geophysical well logs allowed the generation of a high-resolution sequence stratigraphic framework. The Viking Formation is subdivided into four discrete depositional sequences (Sequences 1-4), but this study focuses on Sequence 3, as it constitutes the main cored interval in the Crossfield area. Sequence 3 includes eleven sedimentary facies that are grouped into three facies associations (FA1-3). Deposits of FA1 correspond to the transgressive system tract. The overlying highstand system tract encompasses FA2 and FA3. FA3 contains the reservoir sandstone interval, and comprises sanding-upward successions interpreted to represent deposition in a mixed-process wave-dominated, fluvial-influenced symmetric delta.

Document type: 
Thesis
Supervisor(s): 
James MacEachern
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.

Implications of early halo type veins at the IKE copper-molybdenum-silver porphyry deposit, British Columbia, Canada: alteration studies as a guide to ore grade

Author: 
Date created: 
2020-01-17
Abstract: 

The IKE deposit is a Cu-Mo-Ag porphyry deposit located in the southern portion of the Canadian Cordillera in British Columbia, Canada. Significant amounts of early halo type (EHT) veins are found throughout the deposit, which are typically associated with deep-seated porphyry deposits. This project investigates the geochemical properties of EHT veins and how they relate to mineralization. Petrographic studies were carried out on EHT veins to identify the mineral and fluid inclusion assemblages in the EHT veins, and how IKE compares to other deposits. Cathodoluminescence studies confirm a large overprint of potassic alteration, with a limited expression of alteration zoning typically seen in porphyry deposits. Shortwave infrared spectroscopy was used to identify subtle geochemical changes in the alteration minerals. The primary mineral picks, white mica and chlorite absorption features, and illite crystallinity values were examined to qualitatively determine fluid composition and pathways in the deposit and aid in future exploration.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Dan Marshall
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.

Integrated ichnological, sedimentological, and geochronological analysis of the Late Cretaceous Upper Nanaimo Group, Saltspring Island, B.C., Canada

Author: 
Date created: 
2020-04-08
Abstract: 

Integrated ichnological, sedimentological, and geochronological investigation of the Late Cretaceous Nanaimo Group, Saltspring Island, B.C., Canada was undertaken to examine the existing lithostratigraphic mapping and facies characteristics of deep-water slope deposits. Maximum depositional ages from U-Pb dating of detrital zircon grains (N=3744) provide a geochronologic framework for facies relationships studied at a cm-scale over ~1500 m of stratigraphic thickness. Passive gamma-ray emissions (K, U and Th spectra) were collected using a hand-held gamma-ray scintillometer. The results of this integrated analysis suggests that: (1) almost all of the Cretaceous-aged strata in the study area belongs to the upper Nanaimo Group; (2) the youngest zircon grains in the earliest Nanaimo Basin are Middle Jurassic in age, indicating that further study of basin evolution is needed; and (3) integrated facies analysis of thin-bedded slope deposits provides improved criteria for recognizing their different subenvironments compared to employing sedimentological observations alone.

Document type: 
Thesis
File(s): 
Supervisor(s): 
James MacEachern
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.

Magmatic sources to volcanic gas emissions: Insight from the Garibaldi Volcanic Belt, western Canada

Author: 
Date created: 
2019-10-18
Abstract: 

Volcanoes are the surficial representation of the complex interplay of magmatic, crustal, and hydrothermal processes operating below the Earth’s surface. Studying volcanic deposits provides a unique snapshot into the composition of the deep mantle source. Melt inclusions, which are small pockets of magma trapped inside growing crystals, preserve multi-faceted records of magma petrogenesis. Additionally, the magma at depth contains a significant proportion of dissolved magmatic gases. Once these gases become saturated in the magma, they exsolve into a separate vapour phase and ascend quickly to the surface, where they are released as volcanic gases. The composition of gases at the surface can provide valuable insight into the composition of the magma at depth, as well as the shallow-level hydrothermal system. Volcanic gases are an important factor controlling whether an eruption is gentle and effusive, or violent and explosive. A greater amount of gas that separates at depth can trigger large, explosive eruptions (Devine et al., 1998; Shinohara, 2008). Therefore, gas detection at the surface is an essential monitoring tool for eruption forecasting. In this thesis, I begin with an in-depth look inside glassy and crystallized olivine-hosted melt inclusions and assess the nature of micron-scale solid phases occupying the vapour bubble. From here, major, volatile and trace element compositions of olivine-hosted melt inclusions from every centre along the Garibaldi Volcanic Belt (GVB) reveals a north to south transition from an enriched mantle signature, to a subduction-modified depleted mantle source. Finally, the recent re-discovery of fumaroles beneath the summit glacier of Mount Meager has prompted the first MultiGAS survey in the GVB. The plumes are H2S, CO2 and H2O rich, and hot enough to melt through the overlying ice. Can the basaltic magma, represented by melt inclusions, produce the volcanic gases currently emitted at the surface? To test this, two different gas modelling software (SolEx and MagmaSat) are used, along with original and recalculated (with the bubble components) as input parameters. The resulting molar ratios are compared with MultiGAS ratios of fumaroles. Overall, SolEx closed-system degassing using recalculated melt inclusions yields the best approximation to MultiGAS ratios. This thesis addresses a compositional knowledge gap within the GVB. By understanding both the distinct magmatic sources underlying the arc, as well as the composition of volcanic gases emanating from summit fumaroles, we gain a broad and comprehensive geochemical overview of the Garibaldi Volcanic Belt.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Glyn Williams-Jones
Severine Moune
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) Ph.D.

Engineering geological characterization of the 2014 Jure Nepal Landslide: An Integrated Field, Remote Sensing-Virtual/Mixed Reality Approach

Author: 
Date created: 
2019-12-16
Abstract: 

Characterization of unstable rock slopes can pose a high level of risk toward the geoscientist/engineer in the field due to inaccessibility and safety issues. During recent decades, rapidly developing remote sensing (RS) techniques, including Terrestrial Laser Scanning (TLS), Terrestrial Digital Photogrammetry (TDP), and Unmanned Aerial Vehicle Structure-from-Motion (UAV-SfM) are being progressively employed for landslide investigation and risk assessment. These methods allow acquisition of three-dimensional (3D) data sets from previously inaccessible terrain with sub-centimeter accuracy. This research describes an innovative approach to investigate the preliminary engineering geological characterization of a large (~5.5 Mm3), destructive landslide that occurred on August 2nd, 2014 near Jure in Sindhupalchok, ~70 km northeast of Kathmandu, Nepal. Various methods have been employed including traditional field surveys, RS techniques and preliminary 2D/3D numerical modelling with the objective of understanding conditioning factors, slope failure mechanisms, and identifying/mitigating future hazards at the site. With four years of RS data, analysis of strength degradation and progressive weakening of the rock mass is investigated by linking process of erosion and deposition using 3D change detection algorithms. The slope is still potentially in an unstable state, undergoing progressive rockfalls/slides with the most recent major event (~20,000 m3) in August 2017. Results throughout this thesis, including 2D/3D rock engineering mapping and modelling have been integrated into an interactive 3D Virtual/Mixed Reality (VR/MR) Jure Landslide geodatabase model, enabling an immersive and enhanced engineering 3D geovisualization experience. A comparative 2D/3D, and VR/MR rockfall simulations has been undertaken and developed within an augmented reality Microsoft HoloLens. Moreover, this thesis concludes on how VR/MR techniques can be employed to conduct discontinuity mapping on virtual outcrops and provide a game-changing way that geoscientists can communicate landslide investigation and risk assessment in all stages of rock engineering.

Document type: 
Thesis
Supervisor(s): 
Douglas Stead
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.

Paleoproterozoic tectonometamorphic evolution of the southeastern Rae craton margin

Author: 
Date created: 
2019-12-10
Abstract: 

One of the largest but poorly understood tectonic boundaries in North America is the Snowbird Tectonic Zone (STZ), which separates the Rae and Hearne cratons. Significant tectonothermal reworking of Neoarchean protoliths in the STZ occurred at ca. 2.55 Ga and 1.9 Ga, however, substantial uncertainty persists with regard to the nature and extent of that metamorphism. This thesis focuses on a poorly studied portion of the STZ and adjacent crustal domains within Northwest Territories in order to better understand the nature of 1.9 Ga tectonometamorphism. New mapping revealed a 300 km long and up to 20 km wide crustal-scale shear zone, the Wholdaia Lake shear zone (WLsz). Analysis of hanging wall metasedimentary units returned a new depositional age of 1.98-1.94 Ga. These metasedimentary units, and much of the STZ in the south Rae, were buried and partially melted by ca. 1.92 Ga and began to exhume 7-10 kbar, granulite-facies rocks between 1.92 and 1.90 Ga. Continued amphibolite-facies exhumation of crustal domains was accommodated by the WLsz and other localized extensional shear zones between 1.90 and 1.86 Ga. Much of this high-grade margin was at the surface by 1.83 Ga when new volcanic supracrustal material was deposited. Petrological investigation and Lu-Hf garnet dating of multiple metamorphic assemblages in a mafic granulite from the WLsz has revealed high-grade age components at 2.11 and 1.87 Ga, whereas zircon U-Pb age components are 2.6 and 1.89 Ga. These results highlight a high-grade event at 2.11 Ga not recorded by U-Pb zircon analysis during a poorly understood time of possible extension in the Rae craton. Mapping, U-Pb zircon and titanite geochronology along the STZ at Kasba Lake demonstrates continuity of rock types, isotopic ages and overall shear zone character for >200 km of strike length. Pervasive high-strain occurred between 1.9 and 1.84 Ga within a panel between the Rae and Hearne cratons without obvious coeval metamorphism; however, Archean metamorphism and deformation are also preserved in this region. This panel may be a sliver of Rae crust that was highly strained but never reached high-grade conditions at 1.9-1.8 Ga but likely contributed to exhumation of the STZ region.

Document type: 
Thesis
Supervisor(s): 
H. Daniel Gibson
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) Ph.D.

Merging earth science with environmental education for teachers through inquiry, constructivist and place-based learning

Author: 
Date created: 
2019-12-04
Abstract: 

Recognizing the importance of interdisciplinarity and effective pedagogical implementation, Earth science is incorporated into three of the six modules of an Environmental Education course (EDU452) at Simon Fraser University for teachers, through inquiry, constructivist and place-based learning. The case study research encompasses two pilots with 52 participants in summer 2018 and 2019. Field observations, interviews and pre- and post-course surveys (MESEES) were employed to evaluate the course effectiveness and pedagogies. EDU452 increased students’ recognition of Earth Science being fundamental and relevant. Inquiry learning promoted engagement, yet careful design of overarching questions and guidance adjusted according to individual’s pre-existing knowledge and the conceptual difficulty are recommended. Constructivist and place-based learning are widely accepted by the participants for offering personal ownership of learning, engaging experiences, impactful visuals, and local relevance of knowledge. Conceptual and experiential learners have different understandings of the role of Earth Science. An integrated teaching strategy is believed to enhance the congruency across subjects.

Document type: 
Thesis
Supervisor(s): 
Eileen van der Flier Keller
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.