Issue link: http://resourceworld.uberflip.com/i/832998
J U N E / J U L Y 2 0 1 7 www.resourceworld.com 45 T he Geo-mapping for Energy and Minerals (GEM) program is Canada's largest geo-mapping undertaking since the 1960-70s. Renewed in 2013 under the Harper government, the 12-year, $200 million program is enter- ing its second phase. The program aims to upgrade the geoscience knowledge of Canada's north to inform onshore and off- shore land use decision making, and to support increased exploration for natural resources. I had the opportunity to speak with Sally Pehrsson, leader of the South Rae GEM sub-project. Pehrsson is also one of the originators of Operation GEM, which identified major knowledge gaps to frame second phase GEM projects. For GEM, 'Canada's north' includes the territories and parts of the northern-most provinces. At this scale, the geology is highly varied, and covers 4 billion years of earth's history. As a result, almost every geoscience discipline is involved, with Geological Survey of Canada researchers partnered with provincial and territorial surveys and university researchers. According to Pehrsson, "You have to go back to the big reconnaissance programs in the 1950s and 1960s for something simi- lar in scope, scale and funding (to GEM) ....These were big cross-country map- ping projects that effectively opened up the north to study, and gave industry the confidence to follow. There was a rush of exploration afterwards." The GEM program is similarly making industry waves: "We have found some- thing new and exciting that industry has picked up on in every GEM research area." Projects have identified showings and occurrences of nickel-copper-PGEs, gold, rare earths, and kimberlite disper- sal trains, to name a few. In the NWT Rae craton, VMS and copper-gold anomalies were found within a previously undiscov- ered, low-grade, greenstone belt in an area that was thought to be all granulite facies. As put by Pehrsson, it was a "complete surprise". The South Rae is the most poorly mapped part of the Canadian Shield. Pehrsson's team of ~15 geoscientists are in the process of developing four 250,000 scale regional maps (totalling ~80,000 km 2 ) to upgrade the understanding of the geology and the mineral potential in an area that is virtually unexplored. Pehrsson explains, "The area was last mapped in the 1950s during the first helicoptered reconnaissance geological survey of the arctic...In those helicopters, you couldn't get a lot of lift in light wind conditions, and so they landed at higher elevations to get lift. That meant, in many instances, they were touching on a similar surface within the rolling terrane and did not see the variability of geology." So what has Pehrsson's team uncovered? "We are finding that much of the central part of the Rae is an uplifted and exhumed equivalent of a large scale Tibetan plateau similar to the Himalayas...This has some major science implications, if our hypoth- esis is correct and it extends all the way to Baffin Island, it would be the world's largest exhumed deep crustal ter- rane, even larger than the Tibetan plateau." And in terms of economic potential? "The geology is cur- rently best understood in northern Saskatchewan where there are many past and currently produc- ing mines. Important structures and geology there have now been traced north across the border into the NWT, indicating there is a good chance for some new discov- eries here." n MINING GEM mapping program opening up mineral opportunities by Laura Barker The South Rae GEM2 2015 team. Sally Pehrsson is in the middle wearing the purple jacket. Photo by Eric Thiessen.