Discoveries show potential for diamond mines.
Geoscientists with the Ministry of Northern Development and Mines have confirmed what many prospectors and geologists have suspected for years - Ontario is a prosperous region for diamond exploration.
This affirmation has stirred a renewed interest in diamond exploration in Northern Ontario and has prompted a number of private sector companies to launch exploratory programs throughout the North, says Tom Morris, a quaternary geologist with the MNDM.
"Ontario is an excellent prospect for exploration and has the potential for diamond mines," Morris says. "Not a lot of people were aware of that years ago."
In 1993, the MNDM launched the first in a series of mineral sampling and geophysical surveys to determine the potential for diamond mining in Northern Ontario. The target exploration areas extend from Wawa to Kapuskasing to the James Bay Lowlands, Wawa being the first target area in 1993.
In 1991, a prospector panning out stream sediments in Wawa came across kimberlite type grains. Kimberlite is a host rock to diamonds, but not a source rock: Kimberlite indicator minerals consist of pyrope and eclogitic garnets, magnesian ilmenite, chromite, chorine diopside, forsteritic olivine and diamond and the presence of these minerals is used to determine the proximity of diamond-bearing kimberlites.
Less than 30 per cent of kimberiltes contain diamonds and fewer than one in 200 of the world's found kimberlites have been developed into mines. Of the approximate 300 kimberlites so far discovered in Canada, about 15 may be economic.
A team of geologists with the MNDM surveyed the Wawa area and determined the grams were in fact "exceptional" diamond-bearing kimberlite type rock, he adds. Further studies also indicated the grains, generally stream deposits, were locally derived.
As a quaternary geologist, Morris' studies have been focused on overburden primarily associated with the last glaciation to determine whether or not kimberlite indicators are actually embedded in the bedrock, as opposed to being transported from other areas.
"The key to all of this exploration is that we (the geoscientists) have proven there certainly are diamonds in the rock," Morris says.
Following evaluations in Wawa, the MNDM proceeded with a similar exploration project in Kapuskasing, River Valley and the Terrace Bay area and will be releasing results of studies conducted in the Temagami area this spring. The average cost of mineral sampling and processing within each area is about $100,000.
The focus in diamond exploration shifted from the Northwest Territories where Canada's first economic diamond deposit was discovered in 1991 in the Lac de Gras region, to Ontario following the groundwork of the MNDM.
De Beers Canada Corp., a Canadian company which has been doing diamond exploration in Canada for the past 40 years, entered into advanced exploration stages on the Victor pipe project near Attawapiskat last year. The Victor pipe project is to date the closest one to coming through with a diamond mine in Ontario, says Morris.
However, to bring a diamond mine from initial exploration stages into production could take up to 12 years, he adds.
Although kimberlite indicators had first been discovered near Attawapiskat between 1988 and 1989, De Beers Canada Corp. did not begin detailed exploration in the area until 1997, says Jonathan Fowler, De Beers Canada Corp. chief geologist for projects.
The deposit discovered by De Beers Canada Corp. is within a cluster of 16 kimberlites located approximately 90 kilometres west of Attawapiskat. Advanced exploration at Victor pipe entails testing of 10,000-tonne bulk samples of kimberlite indicator rock. During the course of summer 2000, an on-site mill operation processed about 250 tonnes of rock sample daily.
The evaluation study will determine the concentration of diamonds in the rock and whether or not there are enough diamonds to support a mine, he explains.
"We have to establish what the value of the diamonds are, and in order to do that we need to collect large enough samples, about 2000 carats, to get an idea about the average value," Fowler says.
About 250 tons of processed kimberlite ore are required to produce a One-carat gem quality polished diamond.
Following advanced exploration, the company will proceed with a feasibility study to determine the viability of a diamond mine in Attawapiskat, The company is anticipating the feasibility study will be completed by the end of the year.
De Beers Canada Corp. consolidated some of its offices to Sudbury where Northern Ontario projects are overseen.
MIT Ventures, a Vancouver-based junior mining company, has been putting together a portfolio of potential diamond properties in Northern Ontario over the last year.
The company has staked out between 300 to 400 claims throughout New Liskeard, Temagami and Wawa, says Scott Jobin-Bevans, a consulting geologist for MIT Ventures.
Kimberlite samples from target areas have been processed and the data is now being compiled and reviewed. The company is gearing up to do an exploration program which will involve overburden sampling and geophysical surveys to define anomalous areas, he adds.
While it's too soon to predict whether or not one of the three areas holds the potential for a diamond mine, results to date have been positive, he adds.
"The work the MNDM has been instrumental in keeping diamond exploration going in Northern Ontario," Jobin-Bevans says. "There's been a renewed interest in exploration. I think you have to believe it when you see it and we're quite confident Ontario diamonds will start to fly."
In the 1980's, prospectors had found some of the chemical properties of indicator minerals in these potential target areas, but weren't finding gem quality diamonds, he adds.
Today, geologists are locating many of the diamondiferous kimberlite, t and much of this can be attributed to the use of technology which allows diamond drilling to reach, greater depths through the bedrock, he adds.
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|Publication:||Northern Ontario Business|
|Article Type:||Brief Article|
|Date:||Mar 1, 2001|
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