Pook

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Au
Other commodities Hg
Ore minerals chalcopyrite; gold; pyrite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale PM
Quadrangle map, 1:63,360-scale A-2
Latitude 55.195
Longitude -160.625
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is approximately 4,000 feet northwest of Apollo Mountain on Unga Island (Wilson and others, 1988, locality 28). The map site is at an elevation of about 750 feet, in the SE1/4 of sec. 35, T. 75 S., R. 75 W., of the Seward Meridian. The location is accurate to within 1,200 feet.

Geologic setting

Geologic description

The Pook prospect is in rocks mapped as the late Eocene to early Oligocene Popof volcanic rocks (Wilson and others, 1995). It is a northeast-striking, gold-bearing pyritic quartz-calcite vein system 10 to 70 feet wide and 2,000 feet long (Trujillo and others, 1981). A trace of chalcopyrite occurs in some of the veins. Individual veins in the system are as much as 15 feet thick. The mineralized zone occurs along a fault contact between a basalt flow and a sequence of pyroclastic rocks and andesite flows. The vein material is sheared and crushed and shows evidence of repeated movement, resulting in a complex structural pattern.
Anomalous gold values occur throughout the entire length of the zone. The best surface grades are 0.098 ounce of gold per ton, 1.47 ounces of silver per ton, 210 ppm copper, 1,000 ppm lead, 130 ppm zinc, 300 ppm arsenic, and 0.15 ppm mercury (Trujillo and others, 1981). A single drill hole apparently missed this zone at depth but hit a deeper, 76-foot-thick zone. A 35-foot section of this deeper zone assayed 0.005 to 0.020 ounce of gold per ton and 0.02 to 0.06 ounce of silver per ton.
In 1991 Battle Mountain Exploration Company collected 26 power auger, 19 rock, and 15 soil samples at the prospect in a 2,600- by 1,000-foot area. Eighty percent of these samples returned low-level gold values between 26 ppb and 100 ppb. One high grade vein sample assayed 0.13 ounce of gold per ton (Ellis and Randolph, 1991).
Geologic map unit (-160.627063647609, 55.1941655719704)
Mineral deposit model Epithermal gold vein
Age of mineralization Eocene or younger.
Alteration of deposit The only alteration reported is silicification.

Production and reserves

Workings or exploration
In 1981 Resource Associates of Alaska mapped the prospect, collected about 300 samples, conducted magnetometer and EM surveys, and drilled one 365-foot diamond drill hole. The best metal values obtained from the prospect include 0.098 ounce of gold per ton, 1.47 ounces of silver per ton, 210 ppm copper, 1,000 ppm lead, 130 ppm zinc, 300 ppm arsenic, and 0.15 ppm mercury.
Eighty percent of rock, soil, and power auger samples collected by Battle Mountain Exploration Company in 1991 contained gold values between 26 ppb and 100 ppb. The remainder lacked gold, except for one sample of Pook vein material, which assayed 0.13 ounce of gold per ton.
Indication of production None

Additional comments

The prospect is located on land patented by, or interim-conveyed to, the Aleut Corporation.

References

MRDS Number 10308143

References

Ellis, W.T., and Randolph, D., 1991, Unga project 1991 final report: Battle Mountain Exploration Company report, 36 p. 13 map sheets at various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Trujillo, R.S., Andersen, G.D., MacLeod, T., Hendrick, K., Farnham, S., Peterson, J., 1981. Exploration and evaluation of the Unga-Popof-Korovan Islands portion of lands leased from Aleut Native Corporation: Resource Associates of Alaska report, 70 p., 38 map sheets, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reporters S.H. Pilcher
Last report date 1/10/2001