A Special Issue Devoted to Barite and Zn-Pb-Ag Deposits in the Red Dog District, Western Brooks Range, Northern Alaska

Abstract

The Brooks Range in northern Alaska (Fig. 1) contains an enormous accumulation of zinc and barite. The four deposits at Red Dog (Qanaiyaq, Main, Aqqaluk, and Paalaaq) have reserves and resources totaling 140.6 Mt at 16.6 percent Zn and 4.6 percent Pb (Jennings and King, 2002), which surpass most deposits worldwide in terms of grade and size (Fig. 2). Including resources of the unmined Su-Lik (38 Mt at 9% Zn + Pb; Jennings and King, 2002) and Anarraaq deposits (18 Mt at 23% Zn + Pb; King et al., 2002) northwest of Red Dog, the district has about 40 Mt of contained Zn + Pb (Fig. 2). For comparison, both the Broken Hill deposit and the Mt. Isa district (including the George Fisher, Hilton, and Mt. Isa deposits) in Australia contain more than 50 Mt Zn + Pb (Large et al., 2002). The Australian deposits are lead rich compared with the Brooks Range deposits. In terms of total zinc content, the combined deposits of the Red Dog district (~31 Mt) rival that of the Mt. Isa district (~36 Mt) and surpass Broken Hill (~25 Mt). In terms of zinc concentrate production, the Red Dog mine has the world’s largest—almost 600,000 tonnes (t) per year. The Brooks Range barite deposits are extraordinarily large. The barite body at the Anarraaq deposit alone is estimated to be as much as 1 billion metric tonnes (King et al., 2002). The Wulik, Moil, and Gull barite deposits (Fig. 1) are interpreted to be the lateral equivalents of the Anarraaq barite body (J. Clark, Teck Cominco, pers. commun., 2003), making the total area underlain by these deposits a minimum of 20 km2. Owing to a lack of published information, it is uncertain how this deposit compares with the giant barite bodies in south China, but …