Past Geology Speaker Tours 2018-09-24T14:08:52+00:00

Past Geology Speaker Tours

Science Atlantic is a co-sponsor of an annual speaker tour with the Atlantic Geoscience Society (AGS).

2017-2018 Speaker Tour

Tour coordinator: Deanne van Rooyen

Todd Ventura
Todd Ventura Saint Mary's University

Dates:

Nov. 23, StFX
Nov. 30, Dal

Does Buried Sedimentary Organic Matter Contain a Deep Biosphere Fingerprint?

Extending deep below Earth’s surface lives a microbial ecosystem referred to as the deep biosphere. When these microbes die their remains are recycled, or added to an existing pool of buried sedimentary organic matter. It is hypothesized here that over geologic time even minor additions of this cellular biomass will impact the composition of buried sedimentary organic matter.  This secondary input, however, goes mostly undetected because traditional techniques cannot differentiate ancient molecular components of buried organisms from those supplied by microbiota once living deep within the subsurface. Hydrothermal vent systems have been called “windows to the deep biosphere” because their shallow sediments are host to similar microorganisms with the same metabolic strategies for survival as what exists much deeper in the Earth.  This talk will show the strategies we are perusing to quantitatively define how cellular organic matter is transformed into highly resistant hydrocarbons and if it is possible to identify the molecular constituents added by its subsurface microbiota at the Cathedral Hill vent site in Guaymas Basin, Gulf of California.

Biography

Dr. Ventura received his PhD from the University of Illinois at Chicago in 2006. This was followed with two postdoctoral positions at Woods Hole Oceanographic Institution and the University of Oxford, England. He then worked at GNS Science, the New Zealand crown research institute for geological sciences before joining the geology department at Saint Mary’s University in 2016. Dr. Ventura research interests include organic geochemistry, isotope biogeochemistry, and petroleum geochemistry. His research has focused on the topics of lipid biomarker identification, the characterization of unresolved complex mixtures in ancient (Archean) bitumens and modern hydrothermal systems that produce petroleum, paleoenvironmental reconstruction using lipid biomarkers, oil fingerprinting techniques, and analytical techniques for assessing oil similarity.

Dr. Shannon Sterling
Dr. Shannon SterlingDalhousie University

Dates:

Nov. 17, UNB-F
Jan. 10, SMU
Feb. 7, Acadia

Global Evolution of the Water Cycle

Water: it is essential for all life on the planet, and it makes our planet habitable. Yet, we know surprisingly little about how our water cycle evolved throughout Earth’s history. In this lecture I will propose a new framework for the history of our global water cycle, using the questions; i) how has the water cycle been altered by life?; and ii) how has the water cycle evolved its capacity to support life?  As we explore the answers to these questions, we will examine major changes to the water cycle in Earth’s history, and how these changes altered the habitability of our planet.  We will use insights we learned from a better understanding of the history of the water cycle to gain a new perspective on the future of our water cycle – one in which we face grand challenges in water availability.

Biography

Dr. Sterling has channeled her love of water that began while growing up at the edge of the Capilano River in BC into her hydrology research.  After consulting for several years in watershed assessment and restoration across western North America, she focused her hydrology training at elite international institutions (McGill, UBC, Duke, Université de Paris) to tackle complex problems related to human impacts on rivers and available water.  Her first major discoveries were on how human land cover change alters the global water cycle. When arriving in the Maritimes in 2009, Dr. Sterling founded the Dalhousie Hydrology Research Group and created the Nova Scotia Watershed Assessment and Database. She has established high frequency water quality monitoring systems in several Nova Scotian watersheds. She recently has discovered that metal levels have been increasing in Nova Scotian rivers.  In this seminar she will be presenting results from her latest research that she completed during her sabbatical in Europe – on the evolution of the global water cycle.

2016-2017 Speaker Tour

Dr. James Brenan
Dr. James BrenanDalhousie University

Dates

Todd Ventura
Todd Ventura Saint Mary's University

Dates:

Dal
MUN
StFX

Does Buried Sedimentary Organic Matter Contain a Deep Biosphere Fingerprint?

Extending deep below Earth’s surface lives a microbial ecosystem referred to as the deep biosphere. When these microbes die their remains are recycled, or added to an existing pool of buried sedimentary organic matter. It is hypothesized here that over geologic time even minor additions of this cellular biomass will impact the composition of buried sedimentary organic matter.  This secondary input, however, goes mostly undetected because traditional techniques cannot differentiate ancient molecular components of buried organisms from those supplied by microbiota once living deep within the subsurface. Hydrothermal vent systems have been called “windows to the deep biosphere” because their shallow sediments are host to similar microorganisms with the same metabolic strategies for survival as what exists much deeper in the Earth.  This talk will show the strategies we are perusing to quantitatively define how cellular organic matter is transformed into highly resistant hydrocarbons and if it is possible to identify the molecular constituents added by its subsurface microbiota at the Cathedral Hill vent site in Guaymas Basin, Gulf of California.

Biography

Dr. Ventura received his PhD from the University of Illinois at Chicago in 2006. This was followed with two postdoctoral positions at Woods Hole Oceanographic Institution and the University of Oxford, England. He then worked at GNS Science, the New Zealand crown research institute for geological sciences before joining the geology department at Saint Mary’s University in 2016. Dr. Ventura research interests include organic geochemistry, isotope biogeochemistry, and petroleum geochemistry. His research has focused on the topics of lipid biomarker identification, the characterization of unresolved complex mixtures in ancient (Archean) bitumens and modern hydrothermal systems that produce petroleum, paleoenvironmental reconstruction using lipid biomarkers, oil fingerprinting techniques, and analytical techniques for assessing oil similarity.

2015-2016 Speaker Tour

Dr. Alison Malcolm
Dr. Alison MalcolmMemorial University

Dates:

  • Nov. 17, SMU
  • Nov. 18, Acadia
  • Nov. 19, UNB-F

What do we really know? Uncertainty in reservoir monitoring

It is now normal to monitor the chances in oil and gas reservoirs during production through a combination of 4D seismic data sets and microseismic monitoring. 4D seismic data sets are simply repeated (typically) controlled-source surveys done over the same region at different times; they are used to monitor fluid movement to optimize various aspects of reservoir production. Microseismic monitoring involves recording and analyzing the signals from tiny earthquakes generated by the changes in the stress field that are caused by production. Most processing of these data sets give us an answer, but not an idea of how confident we can be in that answer. The work I will present in this talk aims to assess and characterize this uncertainty through two examples. The first is an example from 4D processing in which we use two data sets in an alternating fashion to obtain both a model of changes in the reservoir and a confidence measure on those changes. The second is an example from microseismic monitoring in which we reduce the uncertainty on event locations by locating multiple events together, rather than separately. To do this, we must first agree on a measure of uncertainty, which I will also introduce and describe.

Biography

Alison Malcolm is an Associate Professor in the Earth Sciences Department at Memorial University of Newfoundland. She earned her Bachelor’s degree in geophysics from UBC in 1996 and her PhD in 2005 from the Colorado School of Mines. After some time as a postdoc she spent six years as an Assistant Professor of Geophysics at the Massachusetts Institute of Technology before moving to Memorial in 2014. She has supervised a dozen graduate and undergraduate students and published more than 30 papers and another 30 Expanded Abstracts. In 2012, she was awarded the J. Clarence Karcher Award by the Society of Exploration Geophysicists for promising young researchers. Her research interests include seismic imaging, reservoir monitoring, nonlinear elasticity, and uncertainty quantification.

Erin Adlakha
Erin Adlakha University of Ottawa

Dates:

Sep. 29, Dal
TBA, StFX

Alteration of Uranium Deposits in Atlantic Canada

2014-2015 Speaker Tour

Dr. Deanne Van Rooyen
Dr. Deanne Van RooyenCape Breton University

Dates:

Feb. 9, UNB-F
Feb. 10, SMU
Feb. 11, Acadia

Uncluttering and reactivating and the western Laurentian basement: lessons from the margins of the Thor-Odin dome in southeastern British Columbia

Over the last half century, the southeastern Canadian Cordillera has been a test case for a number of hypotheses regarding the involvement of basement rocks in compressional phases of orogens, and their subsequent exhumation. When high-grade metamorphic rocks were recognized in the core of the Cordilleran orogen, they were seen as mostly passive participants in the orogenic cycle, exposed through erosion or faulting after the orogen had collapsed. Basement rocks were generally thought to preserve pre-orogenic structures and events, and not considered to be major drivers in the orogenic cycle. This changed with the proposal of the core-complex model to explain the crustal architecture of the Cordillera. At this time, crustal scale extension was recognized as an important mechanism for exhuming basement, and this insight lead to a number of new interpretations of the nature and origin of exposed high-grade rocks.

Mechanisms to account for extension-related exhumation of mid-crustal rocks in the Canadian Cordillera can be divided into two broad categories. The first involves exhumation during post-convergent gravitational collapse and includes: (i) core complex models where exhumation post-dates convergence and buoyant crustal material rises in the footwall of low-angle outward dipping shear zones; (ii) large-scale extension models where large tracts of mid-crustal rocks are exhumed in the footwalls of extensional faults; (iii) and vertical flow models in which diapiric ascent of partial melts play a large role. The second broad category of extrusion mechanisms involves ductile extrusion and channel flow in which mid-crustal rocks flow (and sometimes extrude) in a channel during compression in the orogen.

Recent work in the Monashee Complex and other tectonothermal culminations in southeastern BC has highlighted a number of different ways that basement rocks are involved in the Cordilleran orogen, and how inherited crustal architecture contributes to orogenic evolution. This talk will examine some of the important historical interpretations of Cordilleran tectonics, and discuss how the views and interpretations of the so-called “basement” of the Cordilleran orogen have evolved, using examples from the Thor-Odin dome in southeastern BC.

Dr. Chris McFarlane
Dr. Chris McFarlane University of New Brunswick

Dates:

Mar.9, StFX
Mar. 23, MUN
TBA, Dal

Talk 1: Hydrothermal alteration: the role and record of coupled dissolution-reprecipitation
Talk 2: From grain scale to mountain scale: timing and timescales of evolving orogenic processes

2013-2014 Speaker Tour

Dr. Danika Van Proosdij
Dr. Danika Van Proosdij Saint Mary’s University

Dates:

Mar. 7, StFX
Mar. 14, MUN
TBA, Dal

Complexities of space and time: challenges to effective modelling of intertidal ecomorphodynamics

Interpretation of past landscapes and sedimentary sequences within the coastal zone requires an appreciation of the spatial and temporal variability in transport and depositional processes as well as an understanding of feedbacks and interactions with biological agents in the surrounding environment. This understanding is further complicated in the contemporary environment by anthropogenic activities (e.g. tidal power development, dyking, coastal engineering) that influence or constrain natural coastal ecosystem function.  Modelling future behaviour of coastal systems to a changing climate or human activities then needs to distinguish between natural (including episodic events) versus anthropogenic drivers of change. Ecomorphodynamics is the study of the interaction between sediment dynamics, geomorphology and biota across a range of spatial and temporal scales. This presentation will examine the influence of scale in modelling ecomorphodynamics within intertidal ecosystems in the Bay of Fundy as well as the influence of episodic events (e.g. hurricanes, ice) and human activities (e.g. coastal engineering, dyking and salt marsh restoration). The use of geomatics technologies, hydrodynamic modelling, empirical data collection and disaggregated grain size analysis will be explored.

Dr. Hugo Beltrami
Dr. Hugo BeltramiSaint Francis Xavier University

Dates:

Mar. 5, Acadia
Mar. 10, SMU
TBA, UNB

Continental heat gain in a warming climate: Inferences from geothermal data

2013-2013 Speaker Tour

Trevor McHattie
Trevor McHattieNova Scotia DNR Geological Resources Branch

Dates:

Nov. 26, StFX
Nov. 27, Dal
Nov. 29, MUN

Mantle plume dynamics and the chemical and thermal structure of the Archean mantle: Evidence from mafic-ultramafic volcanic successions within the ca. 2.7 Ga Prince Albert Group, Nunavut, Canada

Penny Morrill
Penny MorrillMemorial University

TBA

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2011-2012 Speaker Tour

Dr. Cliff Shaw
Dr. Cliff ShawUniversity of New Brunswick

Dates:

Mar. 13, MUN
Mar. 15, StFX
Mar. 16, Dal

When Magmas Attack

Dr. Fraser Keppie
Dr. Fraser KeppieNS Department of Natural Resources

Dates:

Acadia
UNB
SMU

How do supercontinents breakup? Evaluating the type example of Pangea in Middle America

The periodic formation and breakup of supercontinents through geologic time is a notable characteristic of the plate tectonic evolution of Earth. Are supercontinents simply a statistical consequence of an arbitrary system of plate boundaries, or do they correspond to fundamental changes in the patterns of mantle convection? Once formed, what are the forces which lead to the breakup of supercontinents? In order to answer these questions,  obtaining plate kinematic constraints for key examples is prerequisite. The most recent and best known example of a supercontinent is Pangea, an assembly of continental blocks inferred to be together during the late Carboniferous and early Mesozoic. Inspection of tectonic models reveals that the kinematic constraints on the breakup of Pangea are uncertain, however. For example, whether South America was off the southern United States (Pangea A), or east of Florida (Pangea B), is an unresolved issue. Also, the Gulf of Mexico is believed to have opened in a counter-clockwise fashion during the Jurassic, but candidate mechanisms that could have caused such extension have been speculatively identified at best. I show here how the Gulf of Mexico may have opened initially during the Jurassic as a pull-apart basin between the Mojave-Sonora and West Florida Megashears. Further, I show how pirate mode or pull-up tectonics provides a mechanism for counter-clockwise extension in the western Gulf of Mexico during the late Cretaceous and Cenozoic. If either or both of these processes operated in Middle America, during and after the breakup of Pangea, established tectonic models require revision. Regardless, this analysis suggests that the breakup of Pangea and earlier supercontinents may have been facilitated by shear zones connecting deformation at their exterior margins to deformation within their interiors.

 

2010-2011 Speaker Tour

Tour Coordinator: Ian Spooner, Acadia University

Dr. Peir Pufahl
Dr. Peir PufahlAcadia University

Dates:

Jan. 25: StFX
Mar. 8: Dal
Mar. 25: MUN

Precambrian carbonates and the evolution of the atmosphere

Bioelemental sediments, a new term that encompasses iron formation, chert, and phosphorite, provide the framework for understanding early Earth evolution. Because bioelemental sediments are composed of the nutrient elements, Fe, Si, and P, their precipitation is intimately linked to biological processes that modify ocean-atmosphere chemistry. This talk highlights how sedimentology and the use of modern stratigraphic principles are used to interpret the microbial ecology and geochemistry of Precambrian bioelemental depositional systems.

Dr. Yana Fedortchouk
Dr. Yana FedortchoukDalhousie University

Dates:

  • Jan. 12, Acadia
  • Jan.26, SMU
  • Feb. 10 or 11, UNB-F

A Window into the Mantle

Diamonds store an incredible record of Earth’s history due to their Archean ages and the residence at great depths as deep as the lower mantle. Diamonds come to the surface by entrainment in kimberlites — the deepest mantle-derived magmas. Kimberlites are also famous for their extremely complex composition, poorly understood origin, presumably explosive eruptions indicating very volatile-rich nature, and the absence of the modern examples. In my talk I will show how we can use diamonds to constrain conditions in kimberlite magmas and in various diamond-bearing reservoirs in the mantle. Diamonds undergo partial dissolution during transportation in kimberlites and during residence in the mantle. The morphology of dissolution features strongly depends on the composition and the conditions of the diamond-destructive fluids. Combination of high-pressure-temperature experiments with morphological studies of the natural diamond parcels demonstrated a strong link between diamond dissolution features and the geology of kimberlite pipes. Surface features are different on diamonds recovered from volcaniclastic and hypabyssal kimberlites reflecting presence or absence of the free fluid phase and the mechanism of kimberlite eruption. Further I will show how diamond morphology can help us to constrain the fluid history in various mantle reservoirs and to learn more about the complex evolution of subcratonic mantle.