Quantitative mineral resource assessment of undiscovered mineral deposits for selected mineral deposit types in the Chugach National Forest, Alaska

The Alaska Mineral Resource Assessment Program: Background information to accompany geologic and mineral-resource maps of the Cordova and Middleton Island quadrangles, southern Alaska

“…Geologic environments favorable for formation of volcanogenic massive sulfide deposits are widespread in the Cordova quadrangle, and the likelihood is high that undiscovered resources of copper (and associated zinc, lead, silver, and gold) exist in rocks of the Orca and Valdez Groups (Nelson and others, 1984;Bliss, 1989;Goldfarb and others, in press). Using grade-tonnage models for Cyprus (volcanic rock-hosted) and Besshi (sedimentary rockhosted) massive-sulfide deposit types, Bliss (1989) prepared a probabilistic quantitative assessment of contained metal values for favorable tracts in the Chugach National Forest.…”

Mineral resource assessment of the Chugach National Forest special study area in northern Prince William Sound, Alaska

“…Undiscove red mineral endowmen t Bliss (1989) reports the potential for 1, 3, and 5 undiscover ed (polymetal lic vein type) deposits at the 90 percent, 50 percent, and 10 percent confidence levels for this area. Since none of the deposits in the study area had production , tonnage and grade curves for polymetall ic veins from producing mines (Cox and Singer, 1986) were applied to estimate the undiscover ed metal endowmen t. This process resulted in a total metal endowmen t shown in Table 1.…”

“…The later resource assessment (Bliss, 1989) presents the quantitative estimate of undiscovered mineral deposits in the CNF. The objective was to forecast the amount of various metals in undiscovered deposits likely present in the CNF.…”

“…Only the part of the assessment concerned with polymetallic veins is considered in this study. In the report (Bliss, 1989) all deposit types permissive in the forest are evaluated following the three-part method of assessment developed by Singer (1993 ). Application of the three-part method allows metal endowment of undiscovered deposits to be estimated using a Monte Carlo simulation.…”

“…For the polymetallic veins found in the study area the grade-tonnage model was based on 75 deposits of which 60 percent are from the Slocan Mining District, British Columbia, Canada (Cairnes, 1934 (Bliss, 1989).…”