Pacific Centre for Isotopic and Geochemical Research
Department of Earth, Ocean and Atmospheric Sciences,
The University of British Columbia
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PCIGR’s Matthijs Smit and Universität Bern Researcher Discover Possible Link Between the Evolution of Earth’s Curst and the Emergence of the Oxygen Cycle

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Matthijs Smit examines ancient rocks from the deep crust in Norway during the summer of 2017.

Researchers Matthijs A. Smit (PCIGR, UBC EOAS) and Klaus Mezger (Universität Bern, Switzerland) have discovered a possible link between the long-term evolution of Earth’s crust and the emergence of Earth’s oxygen cycle 3.0 billion years ago. Their findings have been published in Nature Geoscience.

Cyanobacteria may have produced O2 as early as 3.7 billion years ago. Still, it took almost a billion years for that O2 to start accumulating in the shallow oceans and, subsequently, the atmosphere during a period commonly called the Great Oxidation Event (2.4-2.2 Gyr ago). The slow and stepwise rise of O2 in Earth’s atmosphere has always been somewhat of a mystery. Links to the changing composition of continents at the time have been proposed. However, with clear constraints on the average composition of the continents lacking, these links have been difficult to elucidate.

Smit and Mezger decided to approach this problem by letting nature do the sampling. They analyzed the Cr/U chemistry of land-sourced sediments, working from the idea that these rocks sample large areas of the exposed continents and thus may provide a good representation of their average composition.

Their research revealed a staggering change in continental composition between 3.0-2.4 billion years ago. Before this period, the continents were much more rich in Mg and poorer in Si than today, and contained Mg-rich minerals such as olivine. Present-day analogues show that hydration of such mafic crust causes local surface waters to have extremely high pH and high concentrations of O2 scavengers such as methane and dihydrogen. Although rare today, such reducing waters must have been common before 3.0 Gyr ago. Ultimately, it may have been the removal of Earth’s primitive proto-continents and the cleansing of the environment from O2 scavengers, which set System Earth on track towards having an oxygenated and habitable environment conducive to the evolution of higher life forms.

The findings are among the first reported from a new interdisciplinary research program on the formation and evolution of Earth’s earliest continents. In this program, lead-PI Smit and his students use the world-leading analytical facilities at PCIGR to analyze relics of Archean continental crust found in Canada, Greenland, India, South Africa and elsewhere.

For more info, please see the Nature Geoscience article and the UBC News release.

Canada’s Minister of Defence Visits PCIGR

PCIGR was pleased to host the Canadian Minister of National Defence, Harjit Sajjan, for a tour of our nUBC facility on September 8, 2017. The Minister was on campus on behalf of the Minister of Science, Kirsty Duncan, to announce more than $42 million in funding to support fundamental research at UBC through the NSERC 2017 competition for the Discovery Grants program, scholarships, and fellowships. CFI and BC-KDF grants supported the construction of the PCIGR laboratory facilities and a recent NSERC RTI grant contributes to its ongoing operations.

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The Minister with the PCIGR team. Front row (left to right): M. Amini, E. Megyeri-Lawless, A. Fourny, H. Sajjan, D. Weis, G. Murphy, M. Li. Back row: K. Smith, B. Kieffer, R. McMillan, J. Cutts, K. Gordon, V. Lai (photo credit: Paul Joseph)

The nUBC laboratory is classified as a clean room, a very specialized environment designed to reduce contamination. Because contamination can be brought in by people and their clothing, everyone entering the lab was required follow a strict gowning protocol.

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Professor Dominique Weis describes the instruments at nUBC (photo credit: Paul Joseph)

The tour was led by PCIGR Director, Professor Dominique Weis, with assistance from her unique team of research staff and graduate students. The Honourable Minister was accompanied by Professor Gail Murphy, UBC Vice-President Research, and Enikö Megyeri-Lawless, NSERC Director of Research Grants, Engineering and Life Sciences. Many of the features and instruments in the lab were showcased, with a focus on the Nu1700 high-resolution multi-collector ICP-MS. The first of its kind in Canada, this instrument is particularly special due to its large size and specialized components, including a >4-tonne magnet. Of particular interest to the Minister, it is the same type of instrument used in the military to analyze sources of uranium (depleted or enriched).

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The Nu1700 high-resolution multi-collector ICP-MS (photo credit: Paul Joseph)

Another highlight of the tour was the RESOlution M-50-LR, operated by PCIGR research associate, Dr. Marghaleray Amini. The instrument is a laser ablation system, coupled to an ICP-MS, which can ablate a wide range of geological and environmental materials at high resolution and low absorbance. Near the end of the tour, PCIGR graduate students Rhy McMillan, Kate Smith, Jamie Cutts, and Anais Fourny, and postdoctoral fellow Miling Li, had the opportunity to briefly explain their research to the Minister. Their projects speak to the great diversity of research that is enabled by PCIGR’s instruments and staff.

In conclusion, the tour was a great opportunity to showcase why PCIGR is a world-class geochemical facility. Thank you to the Minister and to everyone who joined us! For a detailed photographic report of the event from UBC photographer Paul Joseph, see the UBC Public Affairs album.

Spring 2017 Research Internships at PCIGR

Spring 2017 Research Internships – High School Students at PCIGR

For the second year in a row, PCIGR partnered with STEM Fellowship, a federal non-profit organization that facilitates mentorship and learning in students across Canada, to take part in their Spring Research Internship Program. The program offers grade 11/12 students the unique opportunity to participate in cutting edge research and be mentored by graduate students and postdoctoral fellows over the course of 5 days. This year the program received 60 applications, and PCIGR hosted 8 students from secondary schools across Vancouver. The students were exposed to exciting geochemistry projects, and were mentored by PCIGR graduate students and MAGNET trainees Evelyn Freres, Rhy McMillan, Nichole Moerhuis, Nicole Williamson, and PCIGR postdoctoral fellow and MAGNET trainee, Laura Bilenker. More information about each of the projects is below:

Evelyn’s project – isotopic analysis using MC-ICP-MS

Unknown-1The students were introduced to isotopic analysis using multi collector inductively coupled plasma mass spectrometry (MC-ICP-MS). They were taught how the instrument works, learned how to operate it, and how correction for instrumental mass bias is performed. They also analyzed the solid deposits formed on MC-ICP-MS sampler and skimmer cones using SEM-EDS, and helped to solubilize the deposits in a solution that will be later analyzed using ICP-OES and/or ICP-MS.

Rhy’s project  – sedimentology, stratigraphy, mineralogy, and archaeology

The interns IMG_1602that worked with Rhy were introduced to sedimentology, stratigraphy, mineralogy, and archaeology by working together on their own small project associated with Rhy’s MAGNET Research Award. Their project focused on the mineralogy of sediments from different layers in Scladina Cave, Belgium, and compliments the geochemical analyses of bones from the same layers. The interns prepared 36 smear mounts for X-ray diffraction analyses of sediments, successfully identified the minerals in the sediments, then wrote a draft report of their findings, which were very interesting and unexpected (in a good way).

Nichole’s project – constraining the temporal evolution of the Coast Plutonic Complex

20170313_150028[2]The students helped constrain the temporal evolution of the Coast Plutonic Complex exposed in Vancouver’s mountains. During the week, they experienced every stage of processing and analysis required to turn a rock hand sample into a concentrated mineral separate, and then established the crystallization age for this magmatic rock. Highlights included hands-on use of the LA-ICP-MS to spatially resolve trace element and U-Pb age distribution in zircon, a thorough tour of the nUBC facility by Research Associate, Marg Amini, and succeeding to make a zircon ‘puck’ without losing any zircon! The students were fantastic to work with and Nichole wishes them the very best in their future endeavours.

Nicole’s project – characterizing the bulk mineralogy of paleosol from Hawaii

The studNWilliamson menteesents’ project aimed to characterize the bulk mineralogy of an ancient, 4.5 million year-old, soil (paleosol) from the island of Kauai, Hawaii. The students started by doing research on Hawaii, paleosols, and the XRD method. They then separated the sample into four natural size fractions to test whether there is a mineralogical difference between them. The students then crushed the entire sample, and took two sub-samples per size fraction for hand powdering. Once the sub-samples were powdered, the students prepared smear mounts for the XRD analysis, loaded the instrument, and set up the analysis parameters. Following the analyses, we matched mineral peaks to the XRD spectra and discussed our results. At the end of the five-week period the students prepared a presentation that they will present to the rest of their class about their mentorship and research experience.

Laura’s project – analyzing the Fe isotope composition of pyrrhotite

Cecilia and Eden1The students helped with an ambitious week-long project to analye the Fe isotope composition of the mineral pyrrhotite. They characterized, photographed, sampled, and dissolved 21 pyrrhotite samples before chemically extracting its Fe in the clean lab. Individual masses of Fe were measured by using a multi-collector inductively coupled plasma mass spectrometer. The data they obtained is helping to improve our understanding of how Fe behaves in magma chamber, which eventually solidifies to form a potentially economically important deposit.

 

 

 

Both the interns and mentors benefitted from their experiences in the program:

“Thank you so much for a rewarding experience! Internships that are as immersive as these ones are difficult to find for high school students, and everyone involved was super friendly.” – Intern

“I just want to say thank you to everyone that worked hard on allowing the students to get an insight into the lab environment and what working in a lab setting feels like.” – Intern

“Hosting the STEM interns has been a great experience from start to finish. It’s been a pleasure to provide them with valuable experience and share my passion for research with enthusiastic people!” – Mentor

“I was impressed by the enthusiasm and quality of work from each of my interns, and I sincerely enjoyed hosting and teaching them at PCIGR! I look forward to remaining in touch as our work moves toward publication.” – Mentor

Supporting the training and mentorship of young scientists in geochemistry is an important part of PCIGR’s philosophy, so we were pleased to once again be able to participate in the Spring Research Internship Program. Until next year!