Colloquium Series Speakers

Upcoming

Date: Tuesday, November 29, 2022
Time: 3:30 PM
Location: BGSB 1069

Dr. Erin Adlakha (Department of Geology, St. Mary's UniversityUranium, 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.

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Passed 

Date: Tuesday, October 25, 2022
Time: 1:30 PM
Location: BGSB 1053

Dr. Rachel Newrick (CSEG Distinguised Speaker 2022, P.Geoph., P.Geol.Exploration Geophysicist and InstructorGeophysics …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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Date: Tuesday, September 27, 2022
Time: 1:30 PM
Location: BGSB 1053

Dr. Yongsong Huang (Professor of Earth, Environmental and Planetary Sciences, Brown University) New quantitative paleo-proxies for temperature, sea ice and salinity based on alkenones produced by phylogenetically distinct Isochrysidales species 

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

 

 

There will not be a colloquium event in December 2022.

 

January - TBA

 

Ananya Mallik (Dept. Geoscience, University of Arizona, AZMSA

Date: February
Time:
TBA
Location:
TBA

 

March - TBA