|Quadrangle map, 1:250,000-scale||DE|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Johnson and Gouley prospect is reported to be about a mile south of the head of McLean Arm at an elevation of about 1,500 feet (Cobb, 1978). Maas and others (1991) could not find the prospect, but they did locate two other mineral occurrences in the vicinity. The occurrences are at elevations of 1,450 and 1,480 feet, near the center of the E1/2 of section 2, T. 82 S., R. 89 E. Their location is accurate within 0.2 mile. The Johnson and Gouley prospect is often combined with the Polson and Ickis prospect (DE039), about a mile to the east.|
Although Maas and others (1991) could not find the Johnson and Gouley prospect, which reportedly is near this site, they found two other mineral occurrences nearby. Those occurrences are described in this record. The rocks in the area consist of Silurian or Ordovician syenite and quartz monzonite (Gehrels, 1992).One occurrence is at at elevation of about 1,480 feet. It consists of silicified monzonite that contains clots of pyrite-bearing quartz and calcite. A selected sample contained 208 parts per billion (ppb) gold, 4.4 parts per million (ppm) silver, and 364 ppm molybdenum. The other occurrence is at an elevation of 1,450 feet. It is in monzonite and consists of a quartz-calcite vein up to 0.4 foot thick. The vein contains pyrite, chalcopyrite, and malachite and the monzonite in the wall rock is silicified. Two samples, 0.3 and 0.4 feet long, across the vein contained 1.25 and 7.54 percent copper, 49 and 52 ppb gold, and 17.5 and 46.4 ppm silver. Samples of silicified monzonite wall rock contained 635 to 932 ppm copper, 0.3 to 0.5 ppm silver, and 8 to 14 ppb gold.
|Geologic map unit||(-132.06866227367, 54.7872582298717)|
|Mineral deposit model||Quartz-calcite vein with copper, silver, molybdenum, and gold.|
|Age of mineralization||Silurian or Ordovician or younger.|
|Alteration of deposit||The monzonite wall rock of the vein is silicified.|
|Workings or exploration||Although a prospect is reported in this area, the only work that can be documented is the sampling of mineralization by government geologists.|
|Indication of production||None|
Cobb, E. H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Dixon Entrance quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-863, 34 p.
Gehrels, G. E., 1992, Geologic map of southern Prince of Wales Island, southeastern Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-2169, 23 p., 1 sheet, scale 1:63,360.
Maas, K.M., Bittenbender, P E., and Still, J.C., 1995, Mineral investigations in the Ketchikan mining district, southeastern Alaska: U.S. Bureau of Mines Open-File Report 11-95, 606 p.
Maas, K.M., Still, J.C., Clough, A.H., and Oliver, L.K., 1991, Mineral investigations in the Ketchikan mining district, Alaska, 1990: southern Prince of Wales Island and vicinity: U.S. Bureau of Mines Open-File Report 33-91, 139 p., 12 sheets, scale 1:63,360.
U.S. Bureau of Mines, 1944, Apex Group, McLean Arm, Prince of Wales Island, southeastern Alaska: U.S. Bureau of Mines, Draft Initial War Minerals Report, 14 p.
|Reporters||D.J. Grybeck (Applied Geology)|
|Last report date||9/1/2003|