Mining company explores copper find

CANTWELL - A Canadian mining company has optioned a huge piece of land in the northern reaches of the Matanuska-Susitna Borough with the hope of hauling out copper.

Caribou Copper Resources now holds 10,240 acres about 70 miles east of Cantwell off of the Denali Highway. After drilling test holes this summer, the company is optimistic about what lies underneath the surface of the 4,000-foot mountains.

Copper was first found by the consortium that previously owned the property in the 1960s, said Pierre Vella-Zarb, Caribou Copper president, but the price of copper was too low to make mining financially viable.

In the original horizontal shafts, called adits, the copper was thick enough to touch, Vella-Zarb said.

“They estimated, at that time, 550,000 tons at 5.8 percent of copper,” he said.

While restrictions on Canadian public companies prevent him from making an estimate based on the test holes recently drilled, Vella-Zarb said, “I think that’s on the low side.”

The company is using diamond surface drilling to test the outer boundaries of the copper deposits. As opposed to blasting out holes, this techniques uses a pipe with diamond cutters on the bottom edge. As it rotates and cuts the rock, geologists get a picture of what’s underneath, Vella-Zarb said.

“It’s much higher quality and more information (than blasting),” he said. “We can create a 3-dimensional model of what the mineralized body looks like.”

And Vella-Zarb is pleased with how it is looking now.

“Ours is a high-grade copper. At other operations, in a ton of rocks, they have less than 10 pounds of copper. We have over 100 pounds per ton,” he said.

Even with this summer’s positive results, a full-blown mining operation is at least two to three years away, Vella-Zarb said. The operation is also subject to the Alaska Department of Natural Resources permitting process.

However, Vella-Zarb is not worried about the environmental concerns that have plagued many mining companies in Alaska. The operation will use minimal-impact techniques and most of the mining will take place underground, he said.

To extract the copper, shafts are dug deep into the mountains. The sides of these shafts are blasted, and the loose rock falls into rails cars waiting below. Once crushed and concentrated, the copper is taken by truck to a rail line then shipped to a smelter.

“We’re not doing strip-mining. There are no open pits,” Vella-Zarb said. “If we have an environmental issue, there would be no mining in Alaska.”

Contact Todd L. Disher at todd.disher@frontiersman.com or 352-2252.