|Quadrangle map, 1:250,000-scale||EA|
|Quadrangle map, 1:63,360-scale||D-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This unnamed occurrence is a large mineralized quartz vein that was traced for several hundred feet along a small tributary near the head of Slate Creek. The coordinates are the map location of Foster (1970), in section 1, T. 2 S., R. 25 E., of the Fairbanks Meridian. The location is accurate within one-half mile. This unnamed occurrence is locality 171 on figure 2 in Foster (1970), but there is a misprint in the text that refers to figure 1. Locality 7 in the text of Cobb (1972 [MF-393]) refers to this unnamed occurrence, but the map location of Cobb (1972 [MF-393]) is incorrect due to the misprint in Foster (1970). This unnamed occurrence is locality 57 of Eberlein and others (1977).|
Geologic descriptionThis occurrence is a large mineralized quartz vein in granitic rocks, mostly granodiorite, that can be traced for several hundred feet along a small tributary near the head of Slate Creek (Foster, 1970). The vein is 2 to 5 feet wide, and contains as much as 80 ppb gold, 0.7 ppm silver, and greater than 10,000 ppm arsenic. A felsic dike that cuts granodiorite one-half mile to the east contains 1,000 ppm lead and 1,500 ppm zinc. Felsic dikes are abundant in the headwaters of Slate Creek and form orange-brown stained zones that can be recognized from a distance. The Ole Creek prospect (EA007) is 3 miles to the east. Biotite from a nearby granite on upper Granite Creek (see EA128) adjacent to a gold-bearing quartz-arsenopyrite vein gives a 40Ar/39Ar plateau age of 93.3 +/- 0.5 Ma (Newberry and others, 1996). The veins here are similar and occurrence is also probably Cretaceous or younger.
|Geologic map unit||(-142.649124460723, 64.7713616717172)|
|Mineral deposit model||Possibly Comstock epithermal veins (Cox and Singer, 1986; model 25c?).|
|Mineral deposit model number||25c?|
|Age of mineralization||Biotite from a nearby granite on upper Granite Creek (EA005) adjacent to a gold-bearing quartz-arsenopyrite vein gives a 40Ar/39Ar plateau age of 93.3 +/- 0.5 Ma (Newberry and others, 1996). The veins here are similar and occurrence is also probably Cretaceous or younger.|
|Workings or exploration||Samples were collected at this unnamed occurrence at the headwaters of Slate Creek by the U.S. Geological Survey in 1969 (Foster, 1970).|
|Indication of production||None|
Cobb, E.H., 1972, Metallic mineral resources map of the Eagle quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-393, 1:250,000 scale, 1 sheet.
Cobb, E.H., 1977, Summary of references to mineral occurrences in the Eagle quadrangle, Alaska: U.S. Geological Survey Open-File Report 77-845, 122 p.
Eberlein, G.D., Chapman, R.M., Foster, H.L., and Gassaway, J.S., 1977, Map and table describing known metalliferous and selected nonmetalliferous mineral deposits in central Alaska: U.S. Geological Survey Open-File Report 77-168-D, 132 p., 1 sheet, scale 1:1,000,000.
Foster, H.L. 1970, Analyses of stream-sediment and rock samples from the southwestern and central parts of the Eagle quadrangle, Alaska: U.S. Geological Survey Open-File Report 423, 64 p.
Newberry, R.J., Layer, P.W., Burleigh, R.E., and Solie, D.N., 1996, New 40Ar/39Ar dates for intrusions and mineral prospects in the eastern Yukon-Tanana terrane, Alaska - Regional patterns and significance, in Gray, J.E., and Riehle, J.R., eds., Geological Studies in Alaska by the U.S. Geological Survey, 1996: U.S. Geological Survey Professional Paper 1595, p. 131-159.
|Reporters||R.L. Flynn; M.B. Werdon|
|Last report date||5/1/2002|