Rain

Prospect, Inactive

Alternative names

Steeple Mountain

Commodities and mineralogy

Main commodities Ag; Au
Other commodities As; Cu; Hg; Mo
Ore minerals chalcopyrite; gold; molybdenite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale UK
Quadrangle map, 1:63,360-scale B-1
Latitude 53.25
Longitude -168.28
Nearby scientific data Find additional scientific data near this location
Location and accuracy
The Rain prospect is located approximately 2 miles due south of VABM Ande and corresponds to Christie's (1974) color anomaly 28. The site is part of the Steeple Mountain prospect of Kennecott (Simpson, 1985; Bundtzen and others, 1990, locality 25). The site location is accurate to within 1/2 mile.
This site is one of many occurrences or prospects that occur within a 5 square-mile area, mostly within T. 80 S., R.131 W., of the Seward Meridian. The center of this area is approximately located at VABM Ande.

Geologic setting

Geologic description

This site is similar in character to the Wind and Fog prospects (ARDF numbers UK007 and UK008). However, the metal values at this site are considerably lower. The site is marked by a color anomaly about 7,000 by 5,000 feet in extent. Propylitically altered Tertiary andesites overlie an argillite and diorite basement complex. The volcanic rocks exhibit quartz veining and local silicification.
The quartz is usually white and contains few visible sulfides. The veins are somewhat enriched in arsenic, copper, mercury, and molybdenum and locally in gold and silver. The highest metal values obtained are: 67 ppm arsenic, 200 ppm copper, 201 ppb gold, 125 ppb mercury, 36 ppm molybdenum, 2.1 ppm silver, and 138 ppm zinc (Christie, 1974; Randolph and Ellis, 1989).
Geologic map unit (-168.281977506025, 53.2490828744566)
Mineral deposit model Epithermal gold quartz vein?
Age of mineralization Late Tertiary or younger.
Alteration of deposit The volcanic rocks exhibit regional propylitization, localized silicification, and potassium flooding or secondary growth on primary feldspars. Wall rock adjacent to quartz veins has been silicified and pyritized. No argillic alteration has been recognized.

Production and reserves

Workings or exploration
In 1975 the Aleut-Quintana-Duval JV did sampling at this site as a followup of the discovery of numerous color anomalies in the area. Analyses of 18 rock samples indicated metal values of up to 200 ppm copper, 0.05 ppm gold, 36 ppm molybdenum, 2.1ppm silver, and 138 ppm zinc (Christie, 1974).
Kennecott mapped and sampled this general area in 1985 (Simpson, 1985).
Battle Mountain Exploration in 1989 did detailed sampling and mapping at this site. The sampling (56 rock) gave metal values of up to 67 ppm arsenic, 201 ppb gold, 125 ppb mercury, 34 ppm molybdenum, and 0.8 ppm silver (Randolph and Ellis, 1989).
Indication of production None

Additional comments

This site is on land conveyed, patented, or selected by the Aleut Native Corporation.

References

MRDS Number 10308471

References

Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Randolph, D.B., and Ellis, W.T., 1989, Unalaska project, 1989 final report: Battle Mountain Exploration Company, Alaska District, 41 p., 5 appendices, 11 plates, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Simpson, D.F., 1986, Aleutian Islands project, 1985 final report: Kennecott-Alaska Exploration Company, 54 p. (Report held by the Aleut Native Corporation, Anchorage, Alaska).
Reporters S.H. Pilcher (Anchorage)
Last report date 1/27/2000