National mineral assessment tract GB21 (Massive sulfide, Sierran kuroko)

Tract GB21
Geographic region Great Basin
Tract area 13,500sq km
Deposit type Massive sulfide, Sierran kuroko
Deposit age Mesozoic

Deposit model

Model code 28a.1
Model type grade-tonnage
Title Grade and tonnage model of Sierran kuroko deposits
Authors Donald A. Singer


Confidence Number of
90% 1
50% 3
10% 6
5% 7
1% 8

Estimators: DCox, Singer, Berger, Ludington, Tingley


Explained by D.P. Cox, Steve Ludington, B.R. Berger, M.G. Sherlock, and D.A. Singer, (USGS); and J.V. Tingley (Nevada Bureau of Mines and Geology)
On the delineation of permissive tracts
The Jurassic Black Rock and Triassic Koipato assemblages are delineated as permissive for kuroko massive sulfide deposits because they contain intermediate to felsic marine volcanic rocks in many localities.
Rationale for Numerical Estimates
For the 90th, 50th, 10th, 5th, and 1st percentiles, the team estimated 1, 3, 6, 7, and 8 undiscovered kuroko deposits, comparable in grade and tonnage to the Sierran kuroko massive sulfide model of Singer (1992) (Mark3 index 44), based primarily on the size of the permissive tract.
Singer, D.A., 1992, Grade and tonnage model of Sierran kuroko deposits, in Bliss, J.D., ed., Developments in deposit modeling: U.S. Geological Survey Bulletin 2004, p. 29-32.
Sorensen, M.L., Plouff, Donald, and Turner, R.L., 1987, Mineral resources of the South Jackson Mountains Wilderness Study Area, Humboldt County, Nevada: U.S. Geological Survey Bulletin 1726, 12 p.

Geographic coverage

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