Colloquium Series Speakers

Dr. David Abbott (AAPG Distinguished Lecturer for Ethics & Consulting Geologist LLC)

"Fundamentals of Geoscience Ethics"

Date: Friday, March 8, 2019
Time: 1:30 pm – 2:30 pm
Location: BGS 0153 

Abstract

This talk examines the principles of common morality that underlie written ethics codes including the difference between statements of rules that must be complied with and aspirational statements, the procedure for determining if a violation of a rule is justified, and case histories of common ethical issues in geoscience practice.

2019 C. Gordon Winder Memorial SCUGOG Public Lecture

Dr. Barbara Sherwood Lollar: Canadian Research Chair in Isotopes of the Earth and Environment, University of Toronto: 

"Exploration for Deep Subsurface Life - What Captain Nemo got right and wrong - "

  • Date: Thursday February 7th, 2019 at 7:00PM
  • Location: Middlesex College MC 110
  • Reception to Follow. Free Admission.

About the Speaker:

Dr. Barbara Sherwood Lollar, Companion of the Order of Canada and Fellow of the Royal Society of Canada, is a University Professor in Earth Sciences at the University of Toronto. She is a Canada Research Chair in Isotopes of the Earth and Environment, Director of the Stable Isotope Laboratory, and Past-President of the Geochemical Society. In 2015 she was named a Fellow of the American Geophysical Union. Sherwood Lollar has published extensively in research on stable isotope geochemistry and hydrogeology, the fate of carbon-bearing fluids and gases such as CO2, CH4 and H2 in ancient fracture waters in the Earth’s crust, and the role of deep subsurface microbial populations in carbon cycling. She has been a recipient of many academic awards and most recently the 2012 Eni Award for Protection of the Environment, 2012 Geological Society of America Geomicrobiology and Geobiology Prize, 2014 International Helmholtz Fellowship, 2016 NSERC John Polanyi Award, 2016 Bancroft Award for the Royal Society of Canada and 2018 Logan Medal of the Geological Association of Canada.

Abstract for the Public Lecture:

From Jules Verne’s Captain Nemo, to Astronaut Mark Watney stranded on Mars, we remain fascinated by the theme of Exploration. Fact can be stranger than fiction however as we discover that even here on Earth, there are parts of the planet we have only begun to probe for new habitable domains and microbial ecosystems. Today we will journey with explorers past, present and future as we descend into some of the places on Earth where life ekes out an existence far from the energy of sunlight. We will discuss microorganisms that draw their energy for life not from the sun but from the power of chemistry in the deep dark places of the Earth - in subsurface habitats ranging from the black smoker vents of the ocean’s hydrothermal fields, to deep fracture waters bubbling up 3 km below the surface of northern Canada and in the gold mines of South Africa. What does exploration of Earth’s subsurface habitats tell us about the search for habitability (and life) on Mars or on the moons of Saturn and Jupiter?

Dr. Fred Longstaffe (Distinguished University Professor & Canada Research Chair, Western University)

Light Stable Isotopy of Clay Minerals - Mysteries in the Sheets

Date: Friday, January 25, 2019
Time: 1:30 pm – 2:30 pm
Location: BGS 0153 

Abstract

I will introduce you to the wacky world of sheet silicate isotope science, including what we measure, why we do it, who cares, and whether we know what we are doing. The principles defining the O and H isotope geochemistry of clay minerals were first described in the 1960s and 1970s by Sam Savin, Simon Sheppard, Jim Lawrence, and their colleagues. This framework has been used successfully to trace long-distance fluid flow, to understand weathering, hydrothermal alteration, rock-water interaction and mineralization, to infer climate change, and even to drive some “Mission to Mars” research. It is part of every geochemist’s tool box. But as Peggy Lee and others have belted out over the years, “Is that all there is, is that all there is, if that's all there is my friends, then let's keep dancing …“. As with all things that seem too good to be true, some fundamental but largely ignored problems remain. Among many complexities we don’t like to contemplate are: (1) Isotopic inheritance from a precursor – some clays get their isotopic DNA from their parents, which is a “no-no” in most isotopic thinking. (2) Not all clays retain their isotopic signals of their birth. Some reset their hydrogen isotope composition to new circumstances arising later in the life of the clay, others reset their oxygen isotopes, and still others acquire new isotopic identities quite different from those when they came into being. All this and more, we will explore in a quest to reveal clay isotope crystal chemistry and the mysteries in the sheets.

Dr. Chris Yakymchuk (Assistant Professor, Department of Earth and Environmental Sciences, University of Waterloo)

Recent advances and future challenges in metamorphic petrology

Date: Friday, January 18, 2019
Time: 1:30 pm – 2:30 pm
Location: BGS 0153 

Abstract
Metamorphic geology has evolved substantially over the past few decades. Recent advances in internally consistent thermodynamic datasets and phase equilibrium modelling have provided new insights into the pressure–temperature evolution, density and rheology of the lithosphere. A new generation of geochronology has emerged that now allows rapid and precise in situ dating of accessory minerals that, when coupled with trace element chemistries, can be linked to the growth and consumption of major rock-forming minerals. This information is essential for constructing tectonic models of orogenesis and understanding the long-term thermochemical evolution of the continents. Future challenges include integrating phase equilibria modelling into genetic models of mineral deposits and associated hydrothermal alteration, evaluating the growth and consumption of accessory minerals during metamorphism, and combining thermodynamic calculations of mineral assemblages with geophysical data and geodynamic modelling to understand modern and ancient tectonic processes.

 

Dr. Alan J. Wilson from the Society of Economic Geologists

Life as an Exploration Geologist: what you need to know!

Date: Friday, January 11, 2019
Time: 1:30 pm – 2:30 pm
Location: BGS 0153

Abstract
Alan has worked in the business of mineral exploration for over 25 years, during which time he has built up a wealth of not only technical experience, but also hands-on experiences of some of the challenges a career in mineral exploration brings. In this talk, he reflects on these challenges, but also underscores the beauties of the natural world that serve as a reminder of why accepting such challenges is worthwhile.

 

Dr. Murray Journeay (Natural Resources Canada, Vancouver)

A Profile of Catastrophic Earthquake Risk in Canada

Date: Friday, November 30 2018  

Time: 1:30 pm – 2:30 pm
Location: BGS 0153

Abstract

We present a catastrophic earthquake risk model for Canada that establishes a base of evidence to both inform and empower disaster resilience planning in accordance with policy and technical implementation guidelines established as part of the Sendai Framework for Disaster Risk Reduction (SFDRR). The model is implemented using GEM’s OpenQuake Engine and available public domain information from Canada’s National Census. It extends the scope of probabilistic seismic hazard models currently used to inform Canada’s National Building Code (NBCC) by introducing a structured framework of indicators that profile the physical, social and economic dimensions of earthquake risk at the neighborhood scale (Census DA). Indicators are aligned with the SFDRR monitoring framework and are used to both analyze existing baseline conditions of earthquake risk, and to evaluate opportunities for risk reduction through proactive investments in seismic mitigation. Hotspot areas of concern include densely settled urban centers and rural-remote coastal communities along the active plate boundary of western Canada, including the Cascadia, Queen Charlotte and Yakutat regions; and concentrated urban and rural settlements along reactivated zones of crustal weakness in central and eastern Canada, including the St. Lawrence Valley, northern Appalachians and Atlantic coastal margin. Incentives for risk reduction in these regions are evaluated in terms of both expected return on seismic retrofit investments (RoI) and the ancillary co-benefits of increased building performance with respect to public safety and disaster recoverability. Utility of the model is evaluated in the context of ongoing local and regional planning initiatives in western Canada, and broader efforts to implement UNISDR’s Global Risk Assessment Framework (GRAF) in support of Canada’s National Platform for Disaster Risk Reduction.

Dr. Christopher Weisener (Professor, University of Windsor)

Unravelling Complexity in Environmental Microbial Geochemistry: Making sense out of Chaos?

Date: Friday, November 23 2018  

Time: 1:30 pm – 2:30 pm
Location: BGS 0153

Abstract

Over the course of this century it will be important to identify cost effective/low maintenance solutions for treating contaminants in receiving sediment watersheds. This involves a better understanding of what defines a “natural” environment compared to compromised sites because of increased contaminant loads. Confounding this is the realization that microorganisms within these systems, represent a vast diversity of organisms with unique functional traits essentially a staggering 1 trillion (1012) species based on conservative estimates. Most often we have limited understanding of what defines good bacteria (facilitators) vs. bad bacteria (poisoners) in watersheds under stress. From a temporal and spatial perspective tracking the taxonomic and functional diversity in different settings (e.g. historically impacted vs. none impacted sites) could lead to better understanding of their function. This becomes more apparent if we consider the future impacts of climate change and its influence on the environmental microbiome. These mechanisms are especially evident in sediments receiving historical anthropogenic inputs from N, P, metals (As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, and Zn), and organic pollutants. Questions arise such as what are the baselines targets that can be used and hopefully applied to support remedial action. Conventional geochemical testing and microbial community analyses are limited with respect to their ability to infer real-time, active processes. Thus, many studies have relied on extracting DNA information from either the water column or rely on comprehensive laboratory studies using representative enrichment cultures procured from active sites. In this presentation, case studies involving single mineral & complex sediments will be discussed with the focus on linking physicochemical processes to microbial community function using emerging omics and geochemical applications. This approach can be used to ultimately define and characterize baseline systems and/or optimize or monitor a chosen applied technology from a failure or functional aspect in sediment environments.

Dr. Gail Atkinson (Professor and Industrial Research Chair Department of Earth Sciences, University of Western Ontario)

Unnatural Tremors: The science of fracking and earthquakes, and why it matters

Date: Friday, November 16 2018  
Time: 1:30 pm – 2:30 pm
Location: BGS 0153

Abstract

There has been a significant increase in the rate of felt earthquakes in western Alberta and eastern British Columbia, which has been associated with hydraulic fracturing and wastewater disposal. The increased rate of seismicity and the potential for localized strong ground motions from very shallow events poses an increased hazard to critical infrastructure such as major dams – particularly for older high-consequence structures. I discuss the factors that affect the likelihood of damaging ground motions and examine their implications for hazard assessment and mitigation. A proposed strategy to achieve safety requirements for critical facilities contains elements of both avoidance and mitigation: (i) a "no-go" zone having a radius of ~5 km; and (ii) a monitoring-and-response protocol to track the rate of events at the M>2 level within 25 km, and adjust operational practices if required.

Dr. Paul Durkin (Assistant Professor, Department of Geological Sciences, University of Manitoba)

Revisiting fluvial meander-belt deposits with implications for interpretations of McMurray Formation

Date: Friday, November 9 2018  
Time: 1:30 pm – 2:30 pm
Location: BGS 0153

Abstract

Over the last decade, a series of insightful studies have highlighted fluvial meander-belt features in strata of the Cretaceous McMurray Formation, northeastern Alberta. High-quality 3-D seismic and image-log data reveal immense point bars, while detrital zircon studies have linked these features to a continental scale drainage system. These observations have prompted further investigation into meander-belt deposits, aimed at better understanding complex facies distributions, stratigraphic architecture, and paleoenvironmental interpretations to inform our understanding of bitumen-bearing units. This study utilizes data from the lower Mississippi River and outcropping fluvial deposits of the Western Canada Sedimentary Basin to inform characterization of the McMurray Formation at Surmont, Alberta. An unprecedented dataset consisting of 600 km2 of 3-D seismic and over 1000 well penetrations form the Cretaceous McMurray Formation in northeastern Alberta, Canada, provides a unique opportunity to characterize an ancient continental-scale river system. Paleochannels ranged from 475 to 1180 m wide and from 35 to 50 m deep, with meander-belt width-to-thickness ratios between 100:1 and 400:1. Reconstructed paleochannel migration patterns reveal the evolutionary history of seventeen individual meander-belt elements, including point-bar, counter-point bar, and their associated abandoned channel fill deposits, which have been mapped using core, microresistivity image logs, and seismic data. Results of the study show that intra-point-bar erosion surfaces bound accretion packages characterized by unique accretion directions, internal stratigraphic architecture, and lithologic properties. We provide evidence for channel-belt-edge confinement and development of a counter-point bar, as well as the deposition of side bars and preservation of a mid-channel bar during meander-bend abandonment. Analysis of changes in meander-belt morphology over time reveal a decrease in channel-belt width-to-thickness ratio and sinuosity, which we compare with observations from the lower Mississippi River and attribute to the landward migration of the paleo-backwater limit due to transgression of the Cretaceous Boreal Sea into the Alberta foreland basin.

Dr. Desmond Moser (Professor, Department of Earth Sciences, Department of Geography, University of Western Ontario)

Atomic Worlds; 3D Maps of Time in Minerals from Planetary Crusts

Date: Friday, November 2nd 2018  
Time: 1:30 pm – 2:30 pm
Location: BGS 0153

Abstract

Nano-scale techniques are revealing vestiges of the past once thought lost to geologic time.
Among these techniques is atom probe tomography (APT) - a relatively new method in
geoscience that is advancing the field of geochronology in several ways. APT requires the
fabrication of a needle hundreds of nanometres in length using a focused ion beam SEM. The
surface of the needle is then ionized and evaporated with a pulsed laser, layer by layer, in a
time-of-flight mass spectrometer with a positional ion detection system that allows atomic and
sometimes isotope identification as well as the reconstruction of the original positions of
atoms. The result is a three-dimensional atom-scale map that, when derived from U-Pb
accessory minerals, allows the simultaneous measurement of isotopic ratios and imaging of
chemical nanostructures, sometimes defined by the geochronology isotopes themselves. I’ll
show some of the phenomena that are being revealed with this technique using our group’s
results for ancient zircon and baddeleyite from the Earth and Mars. When combined with
correlative microscopy techniques such as electron backscaLer diffraction (EBSD), we can use
this “Microstructural Geochronology” to identify diffusion processes that signal otherwise
hidden tectonic, impact and fluid events in planetary history. Potential applications to
environmental research and resource analysis will also be presented.

Dr. Carl Mitchell (Associate Professor, Department of Physical and Environmental Sciences, University of Toronto Scarborough)

Monitoring gaseous mercury with a precise, accurate and inexpensive sampler and potential applications to the Menimata Convention on Mercury

Date: Friday, October 26th 
Time: 1:30 pm – 2:30 pm
Location: BGS 0153

Abstract
The Minimata Convention on Mercury is a relatively new global treaty for protecting both human health and the environment from the adverse effects of mercury. Implementing and evaluating the effectiveness of the Minamata Convention requires (1) the identification and characterization of mercury sources to the atmosphere, (2) the long term monitoring of mercury in the vicinity of identified sources to assess effectiveness of local efforts to reduce emission to the atmosphere, and (3) long term monitoring at background sites to assess effectiveness of regional and global efforts to reduce emissions. This talk will describe our group’s recent invention and rigorous testing of a precise, accurate and inexpensive passive air sampler for gaseous mercury that can play an important role in meeting all of these Convention effectiveness goals. The talk will include results from a global-scale calibration exercise, from laboratory experiments (including at Western’s Biotron facility) to quantify the effects of meteorological parameters on sampler performance, and urban and mining site case studies outlining the sampler’s potential for identifying fugitive sources and estimating emissions. Future and ongoing work to better measure surface emissions and to use the samplers for stable isotope-based source attribution will also be discussed.

Dr. Katsu Goda (Associate Professor & Canada Research Chair in Multi-Hazard Risk Assessment, Western University)

"Stochastic Representation of Earthquake Rupture: Applications in Earthquake and Tsunami Research"

Date: Friday, September 28th 
Time: 1:30 pm – 2:30 pm
Location: BGS 0153

Abstract
Earthquake rupture due to mega-thrust subduction events is a complex phenomenon and uncertainties associated with such rupture processes have paramount influence on ground shaking and tsunami. Representation of earthquake sources in seismic-tsunami hazard-risk analysis has major implications on seismic hazard and tsunami hazard maps, and thus risk mitigation and management measures against catastrophic earthquake events critically depend on how such hazard and risk analyses are performed.

The talk introduces a new stochastic modelling technique for earthquake rupture and presents a few applications to earthquake and tsunami research. The method combines stochastic synthesis of earthquake slip and probabilistic earthquake source scaling relationships. The new method is implemented to carry out novel earthquake-tsunami multi-hazard impact assessments and to characterize earthquake-triggered ground deformation probabilistically. The research tools provide innovative means to evaluate the cascading multi-hazards and compounding multi-risks.

 

Dr. Merrin Macrae (Assistant Professor, Department of Geography & Environmental Management, University of Waterloo)

"The Effects of Hydoclimatic Conditions on Biogeochemical Processes in Natural and Disturbed Landscapes"

Date: Friday, September 21st 

Time: 1:30 pm – 2:30 pm

Location: BGS 0153 

Abstract:
The mobilization of contaminants in the environment is driven by the combination of supply and transport mechanisms, both of which vary in space and time, and are impacted by climatic variability and anthropogenic disturbance. The successful management of sustainable water resources and ecosystems requires the use of an ecohydrological approach, where both ecological and hydrological processes are considered, as well as their interactions. This seminar will provide an overview of my research group’s recent progress in this field.  My lab group seeks to (1) quantify nutrient biogeochemical processes in a range of environments; and, (2) characterize how nutrient dynamics in the environment and ecosystem function are affected by hydrology and hydroclimatic change (natural or disturbance). Our recent progress in three areas will be highlighted: (1) Spatio-temporal patterns in hydrologic and biogeochemical export from agricultural areas; (2) Effects of hydrologic change and disturbance on nutrient transformations and mobility in wetlands; and (3) Effects of climate change on the hydrology and biogeochemistry of ponds at high latitudes.