Chineekluk Mountain Prospect, Aniak Mining District, Bethel Census Area, Alaska, USAi

Regional Level Types
Chineekluk Mountain Prospect	Prospect
Aniak Mining District	Mining District
Bethel Census Area	Census Area
Alaska	State
USA	Country

Location: This prospect is on the northeastern shoulder of Chineekluk Mountain, about 0.3 mile northeast of the summit. The prospect is at an elevation of about 1,500 feet in the SE1/4 sec. 21, T. 15 N., R. 49 W., of the Seward Meridian. The location is accurate.
Geology: The Chineekluk Mountain cinnabar prospect is in an N65E-trending swarm of altered, mafic dikes that cut hornfels of the Upper Cretaceous Kuskokwim Group on the northeast flank of Chineekluk Mountain (Cady and others, 1955; Decker and others, 1995; M.L. Miller and T.K. Bundtzen, unpublished field data, 1998, 1999). The cinnabar occurs as: 1) isolated grains up to 5 mm in size and as ellipsoidal lenses in altered dikes; 2) in ferricrete breccia zones in hornfels; and 3) in quartz veinlets that intrude both hornfels and the altered mafic dikes. Euhedral, bright-red cinnabar grains are up to 1 cm in diameter. Three cinnabar-bearing zones occur over a distance of about 300 feet on the shoulder of Chineekluk Mountain. Each mineralized zone ranges from 50 to 100 feet long and from 15 to 45 feet thick. The cinnabar-bearing quartz veins are locally controlled by small, northwest-trending, high angle fractures that are oblique to the general northeast trend of the altered mafic dikes. Chip and grab samples of cinnabar mineralization of all three types described were collected (M.L. Miller and T.K. Bundtzen, unpublished analytical data, 1998 and 1999). They contain up to 1.63 percent mercury, 12 parts per billion (ppb) gold, 14.3 parts per million (ppm) silver, 109 ppm antimony, 1,120 ppm lead, 2,310 ppm zinc, 5.5 ppm cadmium, 57.4 ppm tungsten, and 601 ppm strontium. The Chineekluk Mountain mercury deposit may contain specimen quality crystalline cinnabar.
Workings: M.L. Miller found the Chineekluk prospect during geologic mapping by the U.S. Geological Survey in 1998. The prospect was sketched and sampled the following year (T.K. Bundtzen, unpublished field data, 1999).
Age: Undated; the nearby Fairview prospect (ARDF SM019) has a 40Ar/39Ar age of 72.6 Ma (Gray, Gent, and others, 1997).
Alteration: Silica-carbonate alteration of mafic dikes.

Commodities (Major) - Hg; (Minor) - Ag, Au, Bi, Cd, Pb, Sr, W, Zn
Development Status: None
Deposit Model: Silica-carbonate mercury? (Cox and Singer, 1986; model 27c).

Other Databases

Link to USGS - Alaska:	SM057

Other Regions, Features and Areas containing this locality

References