Get new articles sent directly to
Earth Explorer is an online source of news, expertise and applied knowledge for resource explorers and earth scientists. Sponsored by Geosoft.
March 5, 2017
March 1, 2017
February 28, 2017
February 28, 2017
January 19, 2017
"You have to be an innovator growing up on a farm," says Vowles, a project geophysicist for HudBay Minerals Inc., who once outsmarted his childhood friends by crafting a unique wooden bow that could shoot an arrow further than anybody else's.
When it came time to consider a career, Vowles didn't gravitate naturally towards farming. But after a childhood spent outdoors, he couldn't fathom the idea of an office job either.
"I wanted to get into an occupation that allowed me to work outside in exciting settings and the choice was either geoscience or forestry. I was accepted into geological engineering technology."
Pity the forestry sector. In the decades since graduating from Sault Ste Marie's Cambrian College in 1970, Vowles' innovative streak has contributed to several discoveries for HudBay in northern Manitoba, including the Lalor zinc-gold deposit in the Flin Flon greenstone belt for which Vowles shares the 2009 Bill Dennis award for Canadian discovery of the year with geologist Kelly Gilmore.
In mid-2009, six drills were still turning at Lalor to upgrade the VMS resource and further investigate newly-found gold mineralization in the deposit. Lalor now has an indicated resource of 3.4 million tonnes grading 1.9gpt gold 20.5 gpt silver, 0.71% copper and 8.82% zinc and an inferred resource of 13.2 million tonnes grading 2.9gpt gold, 34.1gpt silver, 0.70% copper and 8.19% zinc.
Though some geoscientists have expressed doubts about the efficacy of deep-penetrating geophysical technology as a means of finding new ore, Lalor is proof that using the technology can pay off if you know how to tailor the instruments for the type of deposit you seek.
Seven years ago Chris Roney, a project geologist at the time, recognized that if HudBay was going to find another deposit in the vicinity of the Chisel North mine in northern Manitoba, the company was going to have to look deep, very deep. But exploration budgets were tight, so Vowles proposed a relatively inexpensive experiment to see if he could detect Chisel North 600 metres below surface and use those readings to find a similar deposit.
In order to make the best use of Crone Geophysics' deep-penetrating pulse Pulse EM equipment, Vowles and local contractor Dave Koop decided to double up the copper wire that would send an electric current over a two square kilometer area above the mine. The double wire improved field strength and allowed for better resolution at depth.
"We didn't have the most modern technology at the time," says Vowles. "But to mimic the new capability that was coming out, we set the receiver to take thousands of readings and averaged them until the response from the deposit became crystal clear. People wouldn't normally go to that length to get readings."
The tinkering, "plus a few other innovative tricks that we are not divulging", allowed the equipment to detect the outline of the Chisel Mine at depth. Now it was just a matter of finding the next big one.
At first, that goal looked easy to reach if difficult to execute. After laying more than 3,000 pounds of copper wire and conducting miles of survey over a prospective area of thick bush and frozen lakes, Koop's skilled team knew they had a hit: the data revealed two large, round bull's eyes indicating huge conductive bodies 800 metres below surface.
But after spending $250,000 to drill test the first anomaly, results were disappointing: stringer mineralization with copper and zinc grades that were not high enough to be economic. The project was scrapped.
In 2007, with metal prices soaring, Gilmore won permission to restart the drills and Craig Taylor, the new project Geologist, proposed drilling on the second bull's eye. This time they found the target: zinc-rich massive sulphide over wide intersections. With further drilling, the gold mineralization at Lalor is proving to be just as important as the zinc at a time when gold prices are soaring.
"Lalor might become two mines - a zinc mine and a gold mine – serviced from the same shaft." says Vowles. He believes it is just a matter of time before another, similar deposit is found in the vicinity using a combination of deep penetration EM and borehole geophysics.
Many exploration geoscientists spend their whole careers searching for but never finding the jackpot, but Vowles has participated in several discoveries over his 40-year career with HudBay. Some might argue that geoscientists of Vowles generation had an easier time of it because the ore was more detectable closer to surface.
But Vowles says aspiring geophysicists with good technical skills should be optimistic about their role in finding the next generation of deposits, even though they may not share his advantage of growing up on a farm.
"All of the advancements in geophysics have opened up a huge amount of opportunity, especially in searching for deep deposits. It's a field with a future," he says.