Wed
10 Jul 2024Laurentian University professor shares 4th national medal with PhD graduate
(SUDBURY, ON) Dr. Andrew McDonald, a professor at the Harquail School of Earth Sciences at Laurentian University, is celebrating his fourth Hawley Medal, this time co-authoring with Laurentian alumnus Dr. Christopher Beckett-Brown, and Dr. Beth McClenaghan from the Geological Survey of Canada. The Hawley Medal is awarded to the authors of the best paper to appear in The Canadian Journal of Mineralogy and Petrology in a given year.
The paper, “Trace Element Characteristics of Tourmaline in Porphyry Cu Systems: Development and Application to Discrimination,” was published in March 2023. The Mineralogical Association of Canada presented the Hawley Medal at the 2024 GAC-MAC Annual Conference in Brandon, Manitoba.
Although Dr. McDonald previously received three Hawley medals, when he got a call from the Mineralogical Association of Canada, he was not expecting it to be about an award. “There are so many great papers out there in any given year,” McDonald explained. “But every time I’ve won a Hawley, I’ve shared it with an excellent student. It’s the students that deserve the most credit. When I look back on my career and wonder if I made a difference, I guess this is a sign,” he said.
Dr. Chris Beckett-Brown started graduate studies under McDonald after completing his BSc in Earth Sciences at Laurentian. As a grad student, he dedicated himself to understanding tourmaline. The mineral group is commonly known as a beautiful and collectable crystalline gemstone found in various locations worldwide, but it’s more accurately described as a group of related mineral species.
Beckett-Brown was curious about tourmaline’s importance in porphyry systems as a potential indicator for the presence of copper (Cu), molybdenum (Mo), and gold (Au) deposits. In his PhD thesis, he explains that mineral exploration for porphyry Cu-Mo-Au deposits is challenging and that locating deposits buried in the Earth’s crust is necessary (to meet future demand).
“One of the big drivers for this research was how little work had been done on tourmaline in porphyry Cu-Mo-Au deposits,” Beckett-Brown explained. “Tourmaline is very common in these systems, but studying it is complicated. It’s called ‘the garbage can mineral’ because it can accommodate everything. It also has a complex chemical formula, so tourmaline is incredibly challenging to analyze and understand the results, making it exciting to work on!”
Investigating all known porphyry deposits worldwide, Beckett-Brown examined the scientific literature and analyzed samples to determine tourmaline’s potential as a mineral supergroup whose presence could indicate porphyry Cu-Mo-Au systems. This included a detailed mapping of the world's porphyry systems, emphasizing ones that included tourmaline. He analyzed samples from mineralized porphyry systems (Cu, ±Au, ±Mo) including Casino (Yukon Territory, Canada), Coxheath (Nova Scotia, Canada), Donoso Breccia-Los Bronces (Chile), Highland Valley Copper (British Columbia, Canada), New Afton (British Columbia, Canada), Schaft Creek (British Columbia, Canada), and Woodjam (British Columbia, Canada).
The award-winning paper is one of two that examine the occurrence, textures, and chemistry of tourmaline in mineralized porphyry systems. McDonald explained that “the primary goal of the research was to test whether key features of tourmaline could be used in exploring for undiscovered porphyry systems and, secondarily, to gain insights into how these systems originate and evolve through time. The key paper for which the Hawley medal was awarded demonstrates that the trace-element chemistry of tourmaline (i.e., those elements occurring in parts-per-million concentrations), combined with an understanding of how these elements are incorporated into the mineral, can differentiate between mineralized and unmineralized porphyry systems. This furthers our understanding of earth systems and provides industry with a powerful tool in their exploration quiver."
Contributions from many sources helped to bring this valuable research to the world. Primary research funding was led through the Geological Survey of Canada’s Targeted Geoscience Initiative 5. Scholarships, bursaries, fellowships, grants, and prizes from organizations such as the Society of Economic Geologists, the Mineralogical Association of Canada, the Walker Mineralogical Club, the Natural Sciences and Engineering Research Council, and the Ontario government also supported Beckett-Brown and his project.
Finally, Western Copper and Gold and Woodjam Consolidated Copper (now Vizla Copper) allowed access to their properties and contributed sample donations. Numerous individuals helped with analytical and sample preparation, including Willard Desjardins (petrography lab at Harquail School of Earth Sciences), Dr. William Zhe (microanalytical facilities), Dr. Joe Petrus (laser lab), and Dr. Jeffrey Marsh (laser lab).
Beckett-Brown is currently a Surficial Geochemist at the Ontario Geological Survey, where he restarted the lake sediment sampling program, which has been dormant for ten years and is conducting surficial geochemical studies over top of future deposits. McDonald continues to conduct research, write papers, and challenge his students to investigate big questions with careful observation and a critical lens.
Photos and captions are available upon request.
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Media Contact:
Lynn Bulloch
Communications Manager
Harquail School of Earth Sciences, Laurentian University
705-929-8650
