Unnamed Occurrences (ARDF - SP001; near Weyahok River), Noatak Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrences (ARDF - SP001; near Weyahok River)	- not defined -
Noatak Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

The area is within the Gates of the Arctic National Park and Wilderness and has been closed to prospecting since 1981.
Location: This site represents roughly circular area of about 30 square miles centered at about the midpoint of the Weyahok River, a headwater tributary to the Alatna River. The coordinates are for the approximate center of the area, which is mostly in sec. 4, T. 28 N., R. 16 E., of the Kateel River Meridian. Includes localities 1-4 of Grybeck and Nelson (1981) and is accurate to within 2000 ft.
Geology: The site consists of a sprinkling of small occurrences of epigenetic quartz veins, lenses, and breccia zones less than 3 feet thick that contain various combinations of galena, sphalerite, chalcopyrite, and pyrite. The occurrences are in an area of about 30 square miles in an otherwise monotonous sequence of feldspathic sandstone of the Hunt Fork Shale (Nelson and Grybeck, 1980; Grybeck and Nelson, 1981). Assays of the sulfide-bearing samples show up to 100 ppm Ag and 200 ppm Sb. Our fieldwork (S.W. Nelson and D. Grybeck, unpublished data, 1977-1980), and geochemical sampling (Cathrall and others, 1981) suggest that many additional such deposits may occur in this area. All the occurrences found to date are small and discontinuous and there is no obvious sign of any large deposit within the area. There are two theories about the origin of the deposits: (1) Grybeck and others,1985) cite geochemical evidence that they may be related to a buried felsic intrusion; (2) Schmidt and Werdon (1993) and Schmidt (1997) believe that they are related to post-depositional dewatering of the sedimentary rock section and are similar in origin to other sedimentary-rock hosted mineral occurrences in the Brooks Range.
Workings: The site is defined by a few short traverses and spot stations by USGS in late 1970's, and since closed to exploration.
Alteration: None.

Commodities (Major) - Ag, Cu, Pb, Zn; (Minor) - Sb
Development Status: None
Deposit Model: Polymetallic vein (Cox and Singer, 1986; model 22c. See Schmidt and Werdon, 19

Other Databases

Link to USGS - Alaska:	SP001

Other Regions, Features and Areas containing this locality

References