LETTERS Brunswick bigger than Red Dog

I am writing with regard to an article in the May, 1987, issue. The article enti tled “A Jackpot in the Arctic” (i.e. the Red Dog deposit) stated that “among zin c deposits, only the original Broken Hill deposit is larger” and that “Cominco’s Sullivan mine at Kimberley, B.C. ranks third.” In fact this is completely erroneous. Noranda’s Brunswick Mining massive sulphide base metal depos it, near Bathu rst, N.B., was originally larger (in terms of total metal content) than the Red Dog and is still considerably larger than Cominco’s Sullivan mine.

The following information may be of some use for the sake of comparison. The data concerning the Red Dog and Sullivan deposits came directly from th e above me ntioned article. The data concerning Brunswick are official statistics as at Dec 31, 1986. Brunswick, as of this date, had milled 49,298,000 tonnes of ore at a grade of 3.55% lead, 8.80% zinc, 0.31% copper and 94 g silver per tonne. Brunswick also had reserves of 101,404,000 tonnes of 3.6% lead, 8.84% zinc, 0.33% coppe r and 96.4 g silver per tonne.

This translates to a total zinc content of 14,677,606 tons for Brunswick and 14,535,000 tons for Red Dog. The original Brunswick deposit contained m ore zinc m etal than does the original Red Dog deposit, contrary to what was stated in the article. In addition, Brunswick has 9,887,417 tons of total zinc metal remaining in proven reserves while Cominco’s Sullivan has only 2,268,000 tons.

In the future it would perhaps be worthwhile to check your sources rather than take somebody’s word for it. Kelvin R. Pankiw, Geological Technologist