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Magmatic evolution and porphyry–epithermal mineralization in the Taftan volcanic complex, southeastern Iran
No full textThe Taftan volcanic complex is located above the Makran subduction zone in Sistan and
Baluchestan province, southeastern Iran. The earliest volcanic activity at Taftan started in the
late Miocene (~8 Ma) with eruption of andesitic to dacitic lava onto a Cretaceous to Eocene
volcanic and sedimentary paleosurface ~20 km to the northwest of the current volcanic
edifice. Later Plio-Pleistocene volcanism consisted of voluminous andesitic and dacitic lavas
and pyroclastic flows (~3.1 to 0.4 Ma). Taftan, and the neighbouring Bazman volcano, are
the southeasternmost and youngest manifestations of arc-related volcanism in Iran, which
began with the Eocene–Miocene Urumieh-Dokhtar Magmatic Arc (UDMA) in northwest and
central Iran, and extends into western Pakistan (Chagai Arc).
Major porphyry Cu±Mo±Au deposits are associated with Miocene to Pliocene intrusive
rocks in the Kerman section of the Eocene–Neogene Urumieh-Dokhtar Magmatic Arc in
southeastern Iran (e.g., Sar Cheshmeh, Meiduk), and at Reko Diq and Saindak in the Late
Cretaceous–Quaternary Chagai Arc in western Pakistan. In a gap of ~300 km between these
two belts, several porphyry and epithermal prospects are exposed in the Miocene–Pliocene
sections of the Taftan volcanic complex, including the Kharestan (6.10 ± 0.80 Ma) and
Bidester porphyry-epithermal Cu-Au deposits (~4.3 Ma), and the Siah Jangal epithermal Au
deposit (late Miocene). In addition, several argillic to advanced argillic and fumarolic
alteration zones occur in Plio-Pleistocene volcanic rocks around the current volcanic edifice.
These deposits have received limited exploration. Electron microprobe analyses of amphibole (magnesio-hastingsite) phenocrysts and
magnetite–ilmenite mineral pairs from the Taftan and Bazman volcanic rocks indicate a
change of crystallization temperature and magmatic oxidation state from ~1000°C and
FMQ ≈ +1 in andesitic rocks, to ~900°C and FMQ ≈ +2 in dacitic rocks. Magmatic water
content was >4 wt.%, as indicated by the ubiquitous presence of amphibole phenocrysts.
Major and trace element compositions of the Taftan and Bazman volcanic rocks show
calc-alkaline to high-K calc-alkaline affinity, with relative depletions of Nb, Ta, and Ti and
enrichments of large-ion lithophile elements (LILE), Th, and U on normalized diagrams.
These trace element patterns, including listric-shaped normalized rare earth element profiles
and relatively high Sr/Y and La/Yb ratios, are similar to those of fertile Miocene igneous
rocks from the Kerman Belt and Chagai Arc, and suggest that the Taftan suite in particular
should be prospective for porphyry Cu ore formation. Regionally, there is no clear geochemical difference between the Neogene Kerman Belt
rocks, which are thought to post-date the onset of collision between the Afro-Arabian and
Eurasian plates (late Oligocene to earliest Miocene), and the subduction-related Bazman–
Taftan and Chagai Belt magmas. The porphyry deposits formed in these distinct settings are
also virtually indistinguishable. This suggests that most of the processes affecting the
geochemistry and metallogeny of the magmas in both settings take place in the lithosphere,
albeit that the ultimate source of the magmas is in the supra-subduction zone asthenospheric
mantle wedge. In collisional environments, subduction-related material previously
crystallized in the deep lithosphere is simply being remobilized
A qualitative exploration of cardiovascular health and disease messages surrounding Canadian and U.S. campaigns through Facebook and Twitter
No full textCardiovascular disease (CVD) is the leading cause of death and disability among Canadian and
U.S. women. A majority of Canadian and U.S. women are unaware of their CVD risk profiles,
symptoms of acute cardiac events, and take inadequate action to lower their risk. There is limited
understanding regarding the meanings associated with Canadian and U.S. cardiovascular health
campaign messages and user interactivity with these messages on social media. Filling in this
knowledge gap contributes to understanding how women’s beliefs and behaviours are shaped by
prevalent mass media forums, which construct certain portrayals of women’s disease, risk, and
health-related identities. Within this doctoral dissertation, four studies were conducted in order to
explore the media’s role in the social construction of CVD meanings. In the first study, a metasynthesis
was conducted of primary research findings regarding qualitative analyses of mass
media narratives surrounding women’s CVD in Canada and the U.S. Key findings included two
critical, transcendental themes: 1) the medicalized culture of women’s CVD risk, and 2) the
feminization of cardiovascular healthism. The second study was an ethnographic content analysis
of the portrayals of women’s cardiovascular risk and health identities on Facebook page
narratives of the Heart and Stroke Foundation of Canada (HSFC). An overarching theme of
philanthropy as an act of women’s health promotion was identified and three sub-themes: 1) a
culture of consumerism for women’s health promotion, 2) the cardiovascular systems of women
as sites of fear and dependence, and 3) women’s CVD risk, acute events, and treatment as
shared, community experiences. The third study used critical discourse analysis to explore the
Facebook page of U.S. women’s cardiovascular health promotion agency Women’s Heart
Alliance to investigate the discourses through which women’s CVD was portrayed, and the
implications of these discourses on the construction of subject positions for related social agents.
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Women’s CVD was constructed within two central discourses: a discourse of achieving health
equity and a discourse of healthism. These discourses intersected to construct the subject
positions of altruistic fighters, health activists, and compliant patients and consumerists. The
fourth study comprised a critical discourse analysis of the HSFC More Moments campaign
meanings on Twitter for men and women. CVD risk was portrayed through a discourse of
tragedy and loss, and a discourse of life and health, which constructed the subject positions of
visionary leaders, selfless humanitarians, and successful survivors. Collectively, the findings of
these four studies build upon understandings of the media’s nuanced contributions to gendered
constructions of CVD meanings and risk
Sedimentology, stratigraphy, and U-Pb detrital-zircon geochronology of the Meall Dearg Formation, Stoer Group, Torridonian succession, north-western Scotland
No full textThe Meall Dearg Formation is a c.1.2 billion year old sandstone, and represents the
uppermost unit of the Stoer Group (Torridonian succession, north-western Scotland).
Originally described as purely fluvial, the Meall Dearg Formation is here reappraised to
represent coeval fluvial-channelised, floodbasin, and aeolian erg environments by facies
analysis and petrographic methods. Evidence from palaeoclimate indicators points to
humid conditions at time of deposition — inferred from clastic rather than evaporitic
floodbasin strata. U-Pb detrital-zircon geochronology resolved provenance from the
underlying Lewisian Gneiss Complex (comprising several juxtaposed terranes). Erosion
from the Assynt, Gruinard, and Gairloch terranes provided most sediment supply. A
statistical comparison of ages from the fluvial and aeolian deposits revealed that both
underwent sediment transfer and/or were supplied from comparable terranes. The Meall
Dearg Formation, a post-rift fill, is largely comparable to the coeval, pre-Rodinian
Gardar-Rift sequence of Greenland
222Rn measurements within the water phase of the SNO+ experiment
No full textThe SNO+ experiment is a large multipurpose scintillator detector. In the first phase of the
experiment, close monitoring is done to determine radioactivity background levels, in particular the monitoring of 222Rn as its presence can obscure or mimic physics data. This thesis
focuses on a cryogenic technique used to collect and concentrate 222Rn in the water used for
the SNO+ experiment. The target level for 222Rn using this system is 3.5 × 10−14 g
238U/gH2O equivalent for the initial water phase. The radon assay technique and resulting measurements
are discussed.
Further analysis was done to determine the content and locations of areas within the detector
emitting higher than expected rate of events. This is informally known as the "hotspot" problem
Perspectives on indigenous-based programs: the Mishk-Ode-Wendam classroom
Get PDFThe Mishk-Ode-Wendam classroom program was created to assist First Nations, Métis,
and/or Inuit students who live with an addiction or mental health condition to assist them
to obtain their high school diploma. The classroom focuses on supporting their learning
by incorporating their cultural values and its connectedness to the spiritual, emotional,
mental, and physical well-being realms of knowledge. This thesis focused on a program
evaluation of the Mishk-Ode-Wendam classroom program and presents findings gathered
from three Sharing Circles and three individual interviews with a total of seven
participants participating in the Sharing Circles and three participants were individually
interviewed. Key themes emerged from the findings that were classified under strengths,
weaknesses, opportunities and threats
Mercury cycling in a remote boreal drainage basin
Get PDFThe consumption of freshwater fish and seafood is the main source of mercury
(Hg), a widespread neurotoxic pollutant, in humans, a fact which has sparked decades of
research on Hg cycling in aquatic systems. More specifically, the formation and
bioaccumulation of methylmercury (MeHg) is of particular importance because it
biomagnifies through aquatic food webs, resulting in relatively high levels in predatory
fish despite typically low concentrations in the surrounding water.
The main goal of this thesis was to assess how various watershed-level processes
affect Hg bioaccumulation and biomagnification through freshwater food webs across the
relatively pristine Attawapiskat Drainage Basin (ADB) in the remote Far North of
Ontario. This watershed overlaps with the mineral-rich region known as the “Ring of
Fire” which is expected to be heavily developed in the coming decades, likely altering the
physico-chemical environments of surrounding lakes and rivers. In total, 58 lakes and
river sites across the ADB were sampled for surface water quality, aquatic
macroinvertebrates, and fish from 2014 to 2016. Water samples were analyzed for 39
chemical parameters including total Hg (THg; the sum of all Hg species) and MeHg
concentrations ([MeHg]). Biotic samples were analyzed for [THg] and/or [MeHg], as
well as carbon and nitrogen stable isotope ratios, which are indicative of an animal’s food
web position.
In Chapter 1 of this thesis, I provide an overview of our current knowledge on Hg
cycling in aquatic systems of the boreal region. In Chapter 2, I present an extensive
assessment of the chemical, physical, and ecological gradients across the ADB, and an
analysis of the relationships between Hg and these environmental gradients. I determined
that less productive systems with higher concentrations of dissolved organic matter
(DOM) had higher aqueous and biotic [Hg]. In Chapter 3, I examined how changes in the
quality of DOM across the ADB relate to [Hg] in water and biota. Findings from this
study suggest that more labile DOM complexes enhance MeHg bioaccumulation into
food webs, while systems with more humic and aromatic DOM had higher aqueous total
[Hg]. The fourth chapter critically examined the speciation of Hg in fish from across the
ADB and showed substantially lower percentages of MeHg (relative to total Hg) in
muscle of smaller-sized fish, particularly those which feed on littoral-based food webs
and had higher lipid content in their tissue. These novel findings challenge the general
assumption, used in many biomagnification studies and consumption guidelines, that all
fish muscle tissue has > 95% MeHg. Finally, in Chapter 5, I discuss the implications of
my research for subsistence fishers, specifically those from remote communities, where
freshwater fish are important for both culture and sustenance. Here I developed some
preliminary approaches to better communicating the risks and benefits of consuming fish
when presenting fish tissue contaminant results in remote northern communities,
including those in and around the ADB.
Understanding the major influences on MeHg cycling is vital to properly
monitoring the effects of industrial development (e.g., the Ring of Fire development) and
climate change, which can greatly alter the physico-chemical environment of surrounding
lakes and rivers. The results from my thesis indicate significant physical and chemical
differences between waters in the two ecozones (i.e., the Boreal Shield and Hudson Bay
Lowlands) across the ADB, presumably due to changes in bedrock geology and riparian
characteristics. No other study, to my knowledge, has explored the effects of landscape
position and the associated changes in physico-chemical characteristics on Hg
bioaccumulation, speciation, and biomagnification on such a large scale. My findings
demonstrate that monitoring programs will need to effectively track changing nutrient
concentrations, DOM characteristics, and Hg bioaccumulation patterns that vary across
large spatial gradients
The mediating role of mindfulness, attention and situational awareness on driving performance in a virtual reality underground mine
No full textLoad-haul-dumps (LHDs) are used to transport materials in underground mining. Due to the
design of LHDs and the design of the mine drifts, these vehicles are implicated in accidents
involving other mining equipment, the mining environment and pedestrians. In 2015, the Ontario
Ministry of Labour published the Mining Health, Safety and Prevention Review, which
recommended that mobile equipment operators need to have a strong situational awareness.
Mindfulness training can be used to improve an individual’s situational awareness and attention.
Mindfulness is a trait that naturally varies amongst individuals. However, it is a technique that
can be taught and with training and practice, a person’s mindfulness levels can improve over
time. There has been limited research conducted in the area of mindfulness and workplace health
and safety; however, there is evidence to suggest that mindfulness training may be a method to
improve workplace safety.
This study measured a person’s inherent mindfulness, attention and situational awareness and
correlated them against driver’s performance measured from within a computer-based virtual
reality underground mine simulator. The simulator, or the Situational Awareness Mining
Simulator (SAMS), provided the virtual reality experience of operating an LHD in an
underground mine. Perception-response time and collisions frequency were measured within the
simulator and used as the measures of driver performance. Situational awareness was measured
within the simulator by questioning the participants about physical aspects of the virtual mine,
such as signage and colour of various objects. Mindfulness was measured using the Mindfulness
Attention Awareness Scale (MAAS) and attention was measured using the Attention-Related
Driving Errors Scale (ARDES-US). Participants (n = 21) operated a load-haul-dump in the simulator for two trials, each
approximately 15-20 minutes in length. Spearman’s correlations showed a relationship between
frequency of collisions and perception-response time (r = .449, p = .05); situational awareness
and collision frequency (r = .507, p < .05); and situational awareness and mindfulness (r = .434,
p < .05). These correlations were present in either Trial 1 or Trial 2, not both trials and thus,
should be interpreted with caution. There was also a significant negative correlation between
MAAS and ARDES-US scores (r = -.516, p = <.05). There were no other correlations present
between ARDES-US scores and any other variables.
This study provides evidence that by cueing individuals to aspects of their surroundings, Level 1
situational awareness (SA) can be increased and further, the relationship between SA and
mindfulness becomes more apparent. No evidence was able to suggest a relationship between
attention levels, as measured by ARDES-US and driving performance, or situational awareness.
The learning curve of adapting to the simulator was substantial, and clouded some of the results,
especially pertaining to collision frequency, and situational awareness
Semi-automation of a rockbreaker system: dynamic modeling and optimal collision-free trajectory planning
No full textIn light of technological advancements, the mining industry is seeing an increase in equipment
automation. A hydraulic rockbreaker is a machine that would bene t from automation. The goal of
this research is to develop some of the necessary algorithms to render a rockbreaker semi-autonomous.
Semi-automation of such systems would allow for improved ease of use, increased productivity and
e ciency of rock breaking operations, reduced maintenance costs while also removing the operator
from harm's way. Several components are necessary to make semi-automation feasible, including a
dynamic model as well as trajectory planning algorithms which generate collision-free trajectories
to be used by a controller. The development of a complete dynamic model for such a system would
allow for better control when using model-based controllers. However, such a model is di cult to
develop in practice, has added complexity and may be computationally expensive. In this work,
simpli ed dynamic models are developed and compared with respect to a complete dynamic model
of the rockbreaker. One of the resulting simpli ed dynamic models, which only considers the inertial
and gravitational e ects of the rockbreaker's mechanical links as well as the gravitational e ects of
its hydraulic actuators, is shown to provide adequate representation of the system so as to be used in
a model-based controller. The work also develops a set of o ine trajectory planning algorithms that
generate time-optimal trajectories which ensure smooth motions and hydraulic valve actuation while
satisfying the system's ow rate constraints. With the addition of a collision avoidance strategy and
collision detection algorithm, the generated trajectories within the system's work environment can
be expected to be collision-free
The volcanic and deformation history, geodynamic setting, and metallogenesis of the Chisel Sequence, Snow Lake, Manitoba, Canada
No full textThe largest Paleoproterozoic VMS district in the world is hosted in the Flin-Flon Glennie
Domain of the Trans-Hudson Orogen. Most of the VMS deposits occur within the Flin Flon and
Snow Lake arc assemblages of the Flin Flon belt. The Chisel sequence of the ca. 1.89 Ga Snow
Lake assemblage is host to six economic VMS deposits; however, its deformation history prior
to ca. 1.86 Ga and its ore-forming volcanic environment are poorly constrained. The Photo Lake
deposit occurs within the Chisel sequence and exhibits anomalous Au and Cu enrichment when
compared to the other Chisel sequence deposits, but the source of this metal enrichment and its
stratigraphic position are unknown.
Detailed field mapping, including lithofacies and structural mapping, was completed at 1:2,000
scale, with local detailed areas at 1:100 or 1:200 scale. Core from 20 Hudson Bay Exploration
and Development (HBED) drill holes were re-logged and an additional 39 drill holes were
examined using whole-rock geochemistry and drill logs provided by HBED to trace the extent of
units. Eighty-two outcrop samples and 65 drill core samples, including 32 sulfide samples, were
analyzed for whole rock major and trace element geochemistry. Eight of the outcrop samples
were also analyzed for whole rock Nd, Hf, and Pb isotopes. Scanning electron microscopy
provided the semi-quantitative compositions of mineral phases in least altered and altered
samples, and quantitative mineral chemical data for pyrite and pyrrhotite were acquired using an
electron microprobe. Trace element maps were produced by laser ablation inductively coupled
plasma mass spectrometry (LA-ICP-MS) for individual pyrite grains in four of the sulfide
samples.
Detailed field mapping, re-logging of selected drill holes, and whole rock geochemistry
completed in this study indicate: 1) the volcanic rocks of the Snow Lake assemblage underwent a
folding and thrusting event prior to 1.86 Ga due to intraoceanic accretion or early accretion to the
Amisk collage; 2) with the exception of the Threehouse unit, the entire Upper Chisel sequence
represents folded and thrust-repeated Lower Chisel sequence strata; 3) the Chisel sequence VMS
deposits, including the Photo Lake deposit, formed within a single time-stratigraphic ore interval
during a protracted arc-rifting event; 4) Au enrichment in the Photo Lake deposits is syngenetic
and can be attributed to a magmatic input; 5) the Anderson VMS deposits formed during
widespread arc rifting, whereas the Chisel VMS deposits formed during localized extension
above a magma chamber in the extended arc