What can be said of the Lalor deposit that hasn’t already been put forward?
It’s been studied and mapped, drilled and surveyed, and looked at from the air and from underground. One would think the ore body near Snow Lake would have given up all its secrets.
Not so. If one thing was learned from a recent case study of the deposit, it is this: you never stop learning or looking.
There were a number of revelations, hunches and facts put forward at a Lalor symposium recently held in Winnipeg (and a few afterwards in putting this story together).
Dave Koop, president of Koop Geotechnical, was one of many presenters at the symposium, and he put forth a few of the facts and revelations.
Koop got his points across well while imparting his vast knowledge of, and enthusiasm for, the deposit he helped find.
The geotech in Koop traced mineral exploration in the area back to 1794, when Hudson’s Bay Company (not Hudbay) explorer David Thompson first recognized the unique geology on Reed Lake while wintering near Reed.
Koop also covered some of the early history of the Edwards / Chisel / Lalor area. From his research he found that Hudson Bay Exploration and Development’s (HBED) first foray into the Chisel Basin came in 1939, when it acquired a group of six claims – known as Edward and Windfall – through a lawyer from The Pas.
Skipping ahead to 1956, HBED did a Boliden electromagnetic survey around the area of a small lake east of Cook Lake, which at the time was called Little Cook Lake – and in 1974 was renamed Lalor Lake.
The information gleaned from the Boliden survey apparently warranted more work and three short holes were drilled in the Cook Lake area; one of them at the northwestern edge of the current ore body. They hit graphite.
However, there were bigger fish to fry that year slightly southeast of Little Cook. This happened when the Lost Lake and subsequently the Chisel Lake ore bodies were discovered.
Koop reported that from 1969 to 1974, HBED reduced the number of claims it held and in that process gave up the area over Lalor. Falconbridge (now Xstrata) staked it and subsequently did a helicopter electromagnetic and a ground-induced polarization survey over it.
Falconbridge likely determined the area was void of minable minerals and consequently dropped it. HBED re-staked the ground in 1977.
Koop said that numerous surveys were done in area over the ensuing years, but the drills were targeting mostly shallow anomalies, closer to surface.
Nevertheless, Lalor’s saga carried on. Koop reported that during the 1980s, geologists Jerry Kitzler, Alan Bailes and Alan Galley recognized an extreme amount of hydrothermal alteration present in the Basin.
They were “supported by Neil Provins, Ted Baumgartner, Dan Ziehlke, Darren Simms, Tony Spooner, Bill Salahub, Dan McKeachnie, and Brian Janser,” Koop said.
In 1984 the Crone Borehole Electromagnetic System was adopted by HBED. Koop said the Borehole system proved its worth by being able to see a 200-metre radius when immersed in drill holes, and the technology had early success at Spruce Point mine.
“In 1987 Jerry Kitzler used the new Borehole EM system with his original Deep Chisel Fence drilling program and Chisel North was discovered,” Koop added.
Based on that initial success of finding Chisel North, a much larger program was designed in 1990, but funds ran short; however, in 1992 a deep drill hole, DUB-33, was the first indication of Lalor’s greatness.
In a 2007 interview for the book Headframes, Happiness, and Heartaches (by James R.B. Parres and Marc Jackson), Kitzler explained what happened in respect to DUB-33 thusly:
“We were so keen on this prospect that we kept proposing it, trying to get even one hole at a time if we could… and we did get a few holes that way. One of them was Dub-33.
“It was a big step out to an area that we figured was close to the middle of the Chisel Basin. And we hit five centimeters of sulphide in that hole. We were pretty excited, because this was right on the horizon. This was down at the 1,200-metre level and we expected that we were getting out to the bottom of the basin. We did a borehole pulse survey on that hole. And it showed that there was something there that we missed, an anomaly that was huge – because they started seeing this thing right from surface. The geophysics people said, ‘Hey, if it’s seeing this thing right from surface, at 1,200 metres away, whatever is down there is huge!’ So we figured that’s got to be the mother lode. It certainly had the potential. But Anglo [Anglo American, HBM&S’s parent company at the time] just would not come up with any more money to put deep holes out there.”
Said Koop: “Jerry Kitzler, Darren Simms and Bill Salahub’s sniffers were going off scale, but HBED budgets had to focus on new discoveries.”
The 777, Photo Lake and Konuto deposits had just been discovered and despite a number of presentations based on DUB-33, it was not to be.
Koop says Anglo decided to make one last attempt at exploration in the Flin Flon-Snow Lake Camp before deciding to sell off HBM&S in 2004.
“They figured the best place to explore was the Chisel Basin,” Koop said. “They knew the favourable Chisel stratigraphy was getting progressively deeper, so they asked the geophysical group to investigate methods to explore at greater depths.”
Koop noted that at that time, Crone Geophysics had just developed a high-speed time domain receiver, capable of collecting higher quality data in a fraction of the time of the receiver that had been employed.
The first order of business, Koop said, was to convince HBM&S management of the need for a high-speed receiver.
“Alan Vowles [of HBED] made a wager, with then-vice-president Ed Yarrow that if the test was successful and they could see the Chisel North lenses 600 metres below surface, then Hudson Bay Mining and Smelting would buy a high-speed receiver,” he said.
It worked. On Nov. 11, 2002 , a survey crew of which Koop was a member detected the Chisel Basin stratigraphy at a vertical depth of almost 1,100 metres.
Koop said that by this time, Chris Roney was in charge of HBM&S’s Snow Lake geology department and was asked to digitally compile 30 years of Snow Lake geology data.
With that daunting task in front of him and the threat of a sale of HBM&S nipping at everyone’s heels, Roney needed to come up with drill targets quickly.
Roney felt the logical thing to do was talk to the man who did the job for decades before him.
“He knew the best thing to do was buy a case a beer and talk to Jerry Kitzler,” said Koop of the encounter. “By the end of the night he came up with a program of close to 16 holes and a key area to do follow-up on. Roney and Alan Vowles developed the follow-up geophysical program based on what Kitzler came up with and by putting the major geological puzzle together.
“This led to the very unconventional geophysical survey that was needed to possibly prove the theories of numerous geologists correct. It was a first geophysical survey of its kind, but interestingly enough it was using the same geophysical technology from 30 years ago. The breakthrough was in the understanding on how to maximize its capability. This was based on the many incredible geophysical leaders of Hudbay.”
An important piece of the puzzle often forgotten, Koop said, is that from 30 years of improving the way HBED mapped and interpreted geophysics, Alistair Callegari developed a new method of displaying the geophysics that came up with the survey showing the Lalor occurrences.
The survey, showing twin bull’s eyes, hung on the walls of HBED for five years “like two eyes saying, ‘What are you waiting for?’” said Koop. “It tortured geologists for years as the occurrences were brought up in almost every HBED drill program planning session, but after discussing the depth, logistics, freeze-up, manpower and money needed, they were forever being put on the back burner.”
Nonetheless, things progressed and on Dec. 22, 2004, Anglo completed the sale of HBM&S and the company was renamed Hudbay Minerals (and later simply Hudbay).
There were still a number of surveys being done after the sale and there seemed to be a lot more money available for this type of work.
By 2007, Kelly Gilmore was Hudbay’s exploration manager and Craig Taylor was in charge of Snow Lake geology. Between them, Koop said, they decided to drill DUB-168 and successfully fought to do so.
As a result, on that fine day in March 2007, geologist Sara Bernauer, who was looking after the drill on DUB-168, logged the core that was laden with Lalor’s impressive blackjack zinc.
“She knew exactly what she’d just hit,” Koop said.
The rest is history – in the making.
(Note: Koop said he would be remiss not to acknowledge the efforts of Glen Gray in this account).
