Lac de Gras rush outdoes Hemlo as continent’s largest

A diamond discovery in the Northwest Territories by Dia Met Minerals (VSE) and BHP-Utah Mines has touched off what is probably the largest staking rush in North American history, says Yellowknife mining recorder Mike Weirmeir.

At last count, 8,800 square miles (22,800 square kilometres) had been staked around the discovery site about 200 miles northeast of Yellowknife. The claim block is bigger than Wales, covering a full degree of latitude, between 64 degrees and 65 degrees, and six degrees of longitude. Since hundreds of claim tags are still outstanding, the block is likely to balloon even more over the next few months. “I expect we’ll record another 1,000 (claims) this month,” says Weirmeir.

Ontario’s Hemlo gold rush of 1981 pales in comparison. That year, 2,700 square miles in northeastern Ontario were staked solid after geologist David Bell made the discovery of his lifetime. Three mines now producing a quarter of Canada’s gold emerged from the land grab and subsequent exploration. Even the Texas Gulf discovery of 1963, which developed into one of the richest base metal orebodies in the world, did not stimulate a rush of equal magnitude.

The nature of diamond exploration sheds some light on why the Lac de Gras discovery — 81 diamonds in a 465 ft. length of core — led to the mother of all rushes. Unlike gold, which is usually related to a continuous geological feature (e.g. a greenstone belt, a fault zone), diamonds are often associated with kimberlite pipes scattered over an area of 40 square miles or more. In some diamond camps, South Africa and Siberia for example, several of these pipe “clusters” may be spread out over hundreds of miles.

So in order to cover the bases, crews are surrounding the Lac de Gras discovery on all sides, using helicopters as a means of transport. Each claim is large — more than 2,500 acres in most cases — and marked with posts every 1,500 ft.

Sources say the stakers are provided with a constant reading of longitude and latitude from a device fitted into the helicopter. In theory, when a pre-determined post site is found, the helicopter lands, allowing a crew member to jump out and hammer in a claim post. But in practice, some say, many of the posts are being dropped from above and will be secured only after the spring thaw.

Despite the staking frenzy, those close to the rush say claim disputes are unlikely to arise even if a commercial diamond deposit is found. The staking has been a collective effort from the beginning, they say, with crews respecting one another’s territory. Also, because of the unusually large size of the claim blocks, boundaries are relatively clear. Accurate claim line readings are provided by the GPS units installed in each helicopter. Monopros, the Dia Met-BHP joint venture and Aber Resources (TSE) are the three largest landholders in the Lac de Gras area.

In the Northwest Territories, a claim must be a minimum of 52 acres and a maximum of 2,582.5 acres in size. Stakers have up to 60 days to file applications with the mining recorder.