Unnamed Occurrence (ARDF - SR214; upper Falling Glacier), Prince William Sound Mining District, Valdez-Cordova Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - SR214; upper Falling Glacier)	- not defined -
Prince William Sound Mining District	Mining District
Valdez-Cordova Census Area	Census Area
Alaska	State
USA	Country

Location: The occurrence is located along a ledge above the north side of Falling Glacier at an elevation of 2,200 feet. It is in the NE1/4 section 35, T. 5 N., R. 5 E., of the Seward Meridian. This is location S-93 of Jansons and others (1984). This location is accurate to within 300 feet.
Geology: This occurrence consists of iron-stained sheared granite that is locally bleached and contains as much as 2 percent disseminated sulfide minerals (Kurtak and Jeske, 1986). The granite in this area belongs to the informally named Nellie Juan granite, which has been dated as 35.5 +/-0.9 my old (Lanphere, 1966). Sulfide minerals include arsenopyrite, chalcopyrite, pyrrhotite, and pyrite. Locally, shear zones, as much as one-half inch wide with 2 percent sulfide minerals, and quartz veins that are a few inches wide, cut the granite (Kurtak and Jeske, 1986). Two random chip samples of sheared, sulfide-bearing granite contained from 77 to 84 ppm copper and from 440 to 590 ppm arsenic, respectively. The two samples contained 0.03 and 0.5 ppm silver and less than 0.03 ppm gold (Kurtak, and Jeske, 1986).
Workings: Two random chip samples of sheared, sulfide-bearing granite contained from 77 to 84 ppm copper and from 440 to 590 ppm arsenic, respectively. The two samples contained 0.03 and 0.5 ppm silver and less than 0.03 ppm gold (Kurtak, and Jeske, 1986).
Age: The intrusion has been dated at 35.5 +/- 0.9 my old ( Lanphere, 1966); the mineralization is less than 35.5 +/- 0.9 my old.
Alteration: Localized bleached zones are present in the sheared granite (Kurtak and Jeske, 1986).

Commodities (Major) - Cu
Development Status: None
Deposit Model: Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

Other Databases

Link to USGS - Alaska:	SR214

Other Regions, Features and Areas containing this locality

References