EXPLORATION ’94 — Field geologists learn to listen for the

A product that looks somewhat like a child’s toboggan and bears the curious name “Beep Mat” is proving to be a useful prospecting tool.

“It’s like having an extra set of eyes for exploring glaciated terrains,” says Peter Cashin, project geologist with Inco (TSE) in Val d’Or, Que. For massive sulphide exploration, “it really has a place, along with a pick and shovel, as a prospector’s tool.”

Manufactured by Instrumentation GDD at Ste-Foy, near Quebec City, the Beep Mat detects conductive and magnetic outcrops or boulders hidden under up to 1.5 metres of overburden.

When the Mat is pulled over an anomaly and makes its titular noise, this means the bedrock causing the anomaly is fewer than 5 ft. deep underneath. The anomaly can then be trenched, with samples picked up and assays performed. The Beep Mat is the brainchild of geophysicist Edwin Gaucher, who co-owns Instrumentation GDD with brothers Regis and Rejean Desbiens. Gaucher put his geophysical training to good use when he devised the Mat and testing it for the first time in Newfoundland in 1976.

“It’s an instrument that could be used on a greater scale because it’s so easy to operate,” Gaucher says. If applied to prospecting for gold, copper, zinc and nickel, “many Beep Mats could be used across Canada.” To make it simple enough for a computer to determine an anomaly, Gaucher constructed the Beep Mat of unicoil, which has a unique reaction to conductivity. The unicoil is inserted in a polyethylene shell. The waterproof Mat, which sells for $7,900 and rents for about $70 daily, uses rechargeable gell cell batteries which last 20 hours and weigh a total of 10 lb. The batteries make different sounds for conductors and magnetite. “It’s a useful product for the type of exploration work we do,” says Gilles Bouchard, district geologist at Noranda’s (TSE) office in Matagami, Que. The company has been using the device for the past three years, mostly north of Matagami.

The Mat can be incorporated into a program without greatly affecting budgets, Bouchard explains. For surface exploration, “the results are very encouraging and the cost is relatively minimal.” Moreover, it takes no more than a day to learn how to use and manoeuvre the machine.

Instrumentation GDD claims that of the 2,000 conductive occurrences sampled up to 1993 using the Beep Mat, 2% revealed ore grade assays of copper, gold, zinc, lead, etc. One open pit is now operating near a test pit which was first sampled with a Beep Mat, and a small copper ore shoot was drilled off after the discovery of an ore float.

Inco was the first major company to use the Mat on a broad range and receive solid results, says engineer Pierre Gaucher who works at his father’s company. Last year, Inco surveyed a 100-sq.-mile area in Quebec, using the Mat.

During the summer, the company dynamited and sampled 400 conductive outcrops and numerous boulders. The field work resulted in several high-grade showings which are now being drilled.

Edwin Gaucher admits the Beep Mat is still not widely known in the industry but says this is changing. The company has produced about 100 Mats and sold about 40 in the past 10 years, mostly in Quebec and Ontario. “I was hopeless at selling them,” he confesses. “I was trying to give them away and nobody wanted them.”

The Beep Mat often provides an impetus to dig in a spot that would normally be ignored, Cashin explains. “In a couple of instances, we were successful in finding good, reasonable base metal sulphides in bedrock and boulders.” He warns, however, that certain terrains are not conducive to application of the device. “You’ve got to be aware of the morphology of the terrain you are exploring,” he said. For example, the unit has difficulty penetrating through conductive glaze but works well in terrain north of Chibougamau, Que. Inco, which first started using the Mat in 1990 on a trial basis, now has four in Quebec and is considering buying more. It is also using the tool near Thompson, Man., and may use it for some international projects. “I don’t think it has reached its potential,” Cashin says.

Pierre Gaucher points out that the Mat can now be used in concert with the global positioning system (GPS) and surface deposit maps to provide greater accuracy. Prospectors equipped with a Beep Mat can now use GPS to enter the longitude and latitude of any anamolies.

Currently, only about 20% of people applying the Beep Mat are using it with the GPS, but that should change. As Pierre Gaucher explains, “more people are now aware of what it can actually do.”

— The author is a freelance writer based in Montreal.