Ontario Geological Survey celebrates 125 years
New Gold’s Rainy River Mine just one of many examples of discoveries attributed to fieldwork carried out by the OGS
When the Ontario Geological Survey (OGS) was founded 125 years ago, geologists accessed the Northern Ontario wilderness by canoe. Modern conveniences like bush planes and satellite phones were unheard of. Even as recently as the 1950s, field crews did without portable fridges, recalls acting OGS director Jack Parker.
“Having a generator for lights in tents was a fantasy. In fact, use of vehicles was a luxury and some of our geologists had to hitchhike to their work locations,” Parker told a packed room celebrating the 125-year milestone at the PDAC in March.
“As acting director of the OGS, I’m personally acquainted with the every day fieldwork that we do,” he confided. “That includes enduring hordes of biting and stinging insects and being chased by black bears, or flying in bush planes and noticing that the pilot has fallen asleep while in the air.”
“The OGS,” proclaimed Minister of Northern Development and mines Michael Gravelle, “plays a vital role in collecting and publishing information about our province’s geology.”
This year, the OGS will be carrying out 15 geoscience projects, including quaternary mapping from Cochrane to Kapuskasing along the Highway 11 corridor in northeastern Ontario, a large airborne geophysics study from the Manitoba border east to Sioux Lookout, and bedrock mapping in the Fort Hope Greenstone Belt. Field crews will also be busy in the Schreiber-Hemlo Greenstone Belt, the Rowan-Kakagi Lake area in northwestern Ontario, in Shebandowan, Thunder Bay, Wawa and Chapleau.
Crews carrying out bedrock mapping projects examine and collect samples of exposed rock, make observations about the geology and map the distribution of different rock types, said Parker.
“Occasionally, we’ll use drill core if there’s been some diamond drilling in the area. We’ll also use airborne geophysical data in areas covered by lakes or overburden to help us make fairly accurate interpretations of what we think is in the subsurface. We map out fault structures and folding structures that give us information about the tectonic history of the area. We collect samples for geochemical analysis for a variety of elements and we do thin section work and petrography on them.”
Literally thousands of young geologists got their start in the industry by slogging through the bush doing fieldwork for the OGS, said Parker.
“We hire between 35 and 50 students every summer – many from Laurentian and Lakehead universities in Sudbury and Thunder Bay. It’s a great opportunity to expose them to practical geoscience.”
Parker himself started with the OGS in 1977 as a first-year university student doing fieldwork in the Geraldton area.
Crews consist of an OGS staff geologist and four students. Accommodations can be in tents, hotels, apartments or tourist lodges, depending on the location. Food is flown in weekly by floatplane to crews working in the Far North.
“They split into groups of two when mapping,” said Parker. “At the end of the day, they get together, talk about what they saw, compare notes, look at rock samples, enter data into a computer and plan for the next day.”
The final interpretations of the project geologists, informed by the results of laboratory testing and age dating, are published within 18 to 24 months.
A project planning process brings together proposals from OGS geoscientists, academics, junior mining companies and prospectors.
“We also look at the vintages of the geological maps across the province,” said Parker. “If an area hasn’t been mapped since the 1930s, it’s a higher priority.”
OGS posters attract a lot of attention from prospectors and exploration companies at geological symposiums, and reports can be downloaded free of charge from the OGS website.
Mineral discoveries can often be attributed to clues buried in OGS reports or findings by field crews.
One example is New Gold’s billion-dollar Rainy River project, 65 kilometres northwest of Fort Frances. Scheduled to go into production in 2017, the Rainy River Mine will employ 450 people and produce 325,000 ounces of gold per year.
The first sniff of gold at Rainy River occurred as a result of an OGS quaternary mapping project in the 1980s, recalled Parker.
“Our geologist was doing some reverse circulation drilling to characterize the surficial sediments and found large amounts of gold in the till material at the bottom of the holes. That encouraged junior mining companies to start drilling in the area and led, in turn, to the discovery of the New Gold property.
The quaternary mapping project probably cost less than $200,000, noted Parker, but has resulted in hundreds and hundreds of excellent paying jobs and a huge economic boost for nearby communities.