In a small clearing in a pine forest south of Ely, three workers man a 40-foot-tall rig, lowering a cable into a small hole that descends nearly half a mile.
For about three weeks, a hollow drill bit tipped with diamonds has been grinding through the rock that starts just below the surface headed to a depth of 2,300 feet. Every 10 feet, workers pull up a section of the drill core — a pole of rock about three inches thick. It takes these workers about 15 minutes to reel all the cable back up and bring the core to the surface.
Workers take the 10-foot-long core, which weighs about 120 pounds, to the Ely Warehouse of Twin Metals, the company planning an enormous mine just south of the Boundary Waters Canoe Area. A team of geologists will analyze every inch of it to help estimate the amount of mineral deposits beneath the ground.
This summer, Twin Metals estimated the land contained nearly $100 billion worth of copper, nickel and precious metals. But that could change later this month when the company is expected to release another estimate.
Continuing reading Dan Kraker’s story.
(Photos by Derek Montgomery for MPR News)