EXPLORATION ’93 — New Dickenson ore zone uncovered a mile

After more than 40 years of continuous operation, Dickenson Mines (TSE) remains a young gold producer with lots of potential, says James Rogers, technical services superintendent of the Arthur White mine. And reserve estimates for the Balmertown, Ont.-based operation support the geologist’s confidence.

With its venerable history, enviable reserves and promising targets on several levels, Dickenson has emerged as a stable producer in a recession-plagued industry.

As a key member of the Red Lake camp, pouring gold since 1949, Dickenson has weathered good times and bad, but the future rests with its reserves. Proven and probable figures stand at 3.1 million tons grading 0.32 oz. gold per ton. Add to that a million tons at the same grade in the “possible” category, and there are enough reserves to carry the mine well into the next millennium. And with bullion production at about 75,000 oz. per year, 1993 will be a benchmark for the mine, which will pour its three-millionth ounce in the autumn.

Regardless of strong reserves, Dickenson continues to diamond drill underground. And although cash for exploration is limited, the efforts appear to be paying dividends at depth.

The most important exploration is occurring a mile underground at the 34th level. “Last year we completed six holes totalling about 11,000 ft. and we confirmed our projections,” Rogers told The Northern Miner. “The last hole we drilled was a glory hole — it picked up a lot of nice intersections.” He explained that the ore zone at depth “repeats itself, rolling east as it did on

the 13th level.” Encouraging intersections over 20 ft. were also encountered. Reserves below the 30th level are about 250,000 tons at 0.30 oz. gold, which Rogers described as conservative. Indicated reserve projections are also positive. “We don’t want to arm-wave,” he said, “but inferred resources on this zone (between the 30th and 34th levels) indicate about two million tons at 0.30 oz. gold.”

Rogers explained the deep-level development program as follows: “We’ll be driving a drift straight out (from the station) and driving up raises. And we’ve got a conceptual plan where Level 34 will be our haulage drift and Level 37 will be our next drift and everything in between will be trackless mining. So there will be an internal ore pass, waste pass, vent raise and a spiral ramp.”

The mine uses traditional track drift, cut-and-fill stoping. However, deep-level ore will be mined via a (mechanized) jumbo complex combined with selective longhole mining, Rogers said.

Deep-level ore is distinct from the ore on other levels. According to Rogers, the former contains “less arsenopyrite, not so much sulphide, and a lot more actinolite or amphibolitic minerals, but the silicification and deformation are generally the same style (as the other ore).” He added that there is “maybe a little more of what we call ductal orebodies or multi-fracture, multi-veinlet occurrances rather than individual veins.”

Encouraging results, including a high degree of visible gold, have contributed to Rogers’ enthusiasm. “The waste pass is up and we are just short of breaking through to it,” he said. “Within the next month, we should be able to start drifting.”

In 1992, Dickenson contracted 85,000 ft. of underground drilling, half of which was exploration. A quarter of that occurred on the 34th level, although ore has also been identified on two other levels.

The company continues to add to its resources on upper levels that were previously assumed to be mined-out. An example is the 6th level “D” zone, where some 95,000 tons grading 0.31 oz. gold have been found. The target is open updip and downdip.

Success has also been encountered in the No. 2 shaft area, at the 26th level. About 85,000 tons of 0.24 oz. gold have been added to the operation’s inventory.

In the end, however, the ability of the Arthur White mine to expand reserves will depend on it remaining productive.

— Rick Smit is a writer from Red Lake, Ont.