National mineral assessment tract AK-AP03 (Cyprus massive sulfide)

Tract AK-AP03
Geographic region AK Peninsula & Aleutians
Tract area 1,467sq km
Deposit type Cyprus massive sulfide
Deposit age Tertiary

Estimates

Confidence Number of
deposits
90% 0
50% 0
10% 1
5% 1
1% 1

Estimators: Wilson, Church, Saltus, Drew, Menzie

Rationale

Explained by Frederic H. Wilson, Stanley E. Church, Richard W. Saltus, Lawrence J. Drew, and W. David Menzie.
On the choice of deposit models
The area is geologically permissive for Cyprus massive sulfide deposits (Singer, 1986) based on the possible occurrence of ultramafic rocks.
On the delineation of permissive tracts
This tract comprises rocks of the Ghost Rocks, Sitkalidak, Sitkinak, and other Tertiary Formations on the southeast and east side of the Kodiak Islands (Moore, 1969). These formations contain a variety of lithologies, including flysch and marine sandstone and siltstone, and possibly ultramafic rocks. This tract is correlated with the Orca Group of Prince William Sound.
Important examples of this type of deposit
The Old Harbor prospect (Berg and Cobb, 1967, p. 87) on Sitkalidak Island may be an example of this type of deposit in the tract.
On the numerical estimates made
The minimum number of undiscovered Cyprus massive sulfide deposits, consistent with the tonnage and grade model of Singer and Mosier (1986) has been estimated at:
Percentile 90 50 10 5 1
Estimated number of deposits 0 0 1 1 1
References
Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p.
Moore, G.W., 1969, New formations on Kodiak and adjacent islands, Alaska: U.S. Geological Survey Bulletin 1274‑A, p. A27‑A35.
Singer, D.A., 1986, Descriptive model of Cyprus massive sulfide, in Cox, D.P., and Singer, D.A., eds., Mineral deposit models: U.S. Geological Survey Bulletin 1693, p. 131.
Singer, D.A.., and Mosier, D.L., 1986, Grade and tonnage model of Cyprus massive sulfide, in Cox, D.P., and Singer, D.A., eds., Mineral deposit models: U.S. Geological Survey Bulletin 1693, p. 131-135.

Geographic coverage

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