Colloquium Series Speakers
2022 - 2023
uPCOMING TALKSwINTER 2023 |
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| Date/Time |
Speaker |
Title | |||
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Tuesday, January 17 |
Speaker: Robert Hearst |
The economics of looking deep with geophysics - Why look deep when I'm only interested in the first XXXm? |
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| Friday, February 3 2:30 p.m. BGS 0153 |
Speaker: Dr. Gerhard Pratt |
Perspectives on the Seismic Inverse Problem: Lessons Learned from the 1980's to the Present | |||
| Wednesday, February 15 1:30 p.m. BGS 1056 |
Speaker: Dr. Ananya Mallik |
How hot and wet is the Moon: insights and challenges | |||
| March |
TBA |
TBA | |||
Previous TALKSfall 2022 |
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| Tuesday, November 29 1:30 p.m. ZOOM |
Speaker: Dr. Erin Adlakha |
Uranium, a Metal on the Move: Examples of Crustal Uranium Cycling in the Churchill Province |
| Tuesday, October 25 1:30 p.m. BGS 1053 |
Speaker: Dr. Rachel Newrick |
Geophysics …the future is so bright, we have to wear shades |
| Tuesday, September 27 |
Speaker: Dr. Yongsong Huang |
New quantitative paleo-proxies for temperature, sea ice and salinity based on alkenones produced by phylogenetically distinct Isochrysidales species |
Upcoming
Time: 2:30 PM
Location: BGSB 0153
Passed
Date: Tuesday, January 17, 2023
Time: 1:30 PM
Location: BGSB 1053
Robert Hearst (KEGS Past President and current member of Board of Directors, Consulting Geophysicist - Americas, Southern Geoscience Consultants) The economics of looking deep with geophysics - Why look deep when I'm only interested in the first XXXm?
Abstract
The growing acceptance of the mineral systems approach to ore deposit generation and fertile areas in the near surface (the infamous "Hand of God" example of Olympic Dam) is forcing many companies to rethink how they conduct their exploration programs. However, often this approach is overridden by the economics of what can be brought into production the quickest and at the lowest cost, hence "I am only interested in an extractable resource that is within 200m or 300m of the surface". A resource, if of sufficient size and grade, within 200 to 300m of surface is essentially considered to be open pitable and hence can often be brought into production in a short timeframe. As a result, in many mining camps the majority of the geophysical exploration that has been completed is restricted to at best 200m or 300m of surface. An understanding of the overall mineralising system is therefore absent and the possibility of higher grade resource at greater depth is unknown. Read more
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Dr. Erin Adlakha (Department of Geology, St. Mary's University) Uranium, a Metal on the Move: Examples of Crustal Uranium Cycling in the Churchill Province
Abstract
Uranium is a “critical mineral” of Canada as an essential metal for Canada’s economic security and a low-carbon source of energy through nuclear power. In 2019, Canada was ranked second in global uranium production and the fourth major exporter, supplying 13% and exporting 12% of the world’s uranium. The largest high-grade uranium resources in the world are in Saskatchewan occurring as unconformity-type uranium deposits, hosted near the contact of the Paleoproterozoic Athabasca Basin with crystalline basement rocks of the Churchill Province. Similar, but lower grade, styles of mineralization are recognized in and below the Paleoproterozoic Thelon, Hornby,
and Nonacho basins, located to the north and northwest of the Athabasca Basin in the Churchill
Province.
Date: Tuesday, October 25, 2022
Dr. Rachel Newrick (CSEG Distinguised Speaker 2022, P.Geoph., P.Geol.Exploration Geophysicist and Instructor) Geophysics …the future is so bright, we have to wear shades
Abstract
The world is facing many global challenges: poverty, insufficient clean water supply, hunger and a lack of energy security amongst others. To tackle them, the world needs critical thinkers, who are curious and inventive. Utilizing a variety of skills and technologies, geophysicists play a significant role in helping the world meet the 2030 UN sustainable development goals. Geophysicists interrogate the subsurface to locate oil, gas, minerals, water, brine, subsurface reservoirs for carbon sequestration, and to improve our understanding of hazards, earthquakes etc. The thought process that we use in exploration can be used as we look forward to the future, progressing oddities to leads and prospects. The future is bright for geophysicists, and for the world because geophysicists are helping address many global challenges.
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Abstract
Long chain alkenones are arguably the most accurate paleotemperature thermometers ever developed. In contrast to isoprenoidal and branched GDGTs, alkenones have much better defined producing organisms (order Isochrysidales of Haptophye algae) and well demonstrated linear temperature correlations based on laboratory growth and global ocean coretop sediment transects. Alkenones are diagenetically highly stable biomarkers hence well suited for paleo-reconstructions. Unsaturation indices of alkenones have been widely and successfully applied for paleotemperature reconstructions for ~ 40 years. Recent studies, however, demonstrate that Isochrysidales are also well adapted to grow in different salinity, stretching all the way from freshwater to hypersaline waters. Salinity (as well as dynamics of salinity during the growth season) is the predominant control on the Isochrysidales speciation. Genomic analyses on seasonal water and sediment samples reveal well defined salinity niches when specific Isochrysidales species flourish. While Isochrysidales respond to temperature changes primarily by adjusting the number of double bonds in alkenones, salinity induced changes in alkenones (and alkenoates) are also reflected by systematic changes in double bond positions, chain length characteristics, resulting from transitions among different Isochrysidales species. Such salinity-induced response is markedly different from the physiological response of alkenone unsaturation ratios of individual Isochrysidales species to temperature. In this presentation, I will review our discovery of freshwater Isochrysidales and associated alkenones, phylogenetic classifications of different groups and sub-groups of Isochrysidales, improvement of alkenone analytical methods and efforts to calibrate alkenone and alkenoate chemotaxonomical changes to salinity, temperature changes. The refined chemotaxonomy has been carried out using laboratory culture experiments, natural surface sediment transects, and estuaries and lakes of wide range of salinity from fresh to hypersaline. I will also discuss a series of paleosalinity and paleohydrological reconstructions from lacustrine and ocean environments, including the Balck Sea salinity reconstruction during deglacial and sea ice reconstruction from LGM to present in Nordic Seas.
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Upcoming
Ananya Mallik (Dept. Geoscience, University of Arizona, AZ) MSA
Date: February
Time: TBA
Location: TBA
March - TBA
