Pfaff

Prospect, Inactive

Alternative names

Battle Lake

Commodities and mineralogy

Main commodities Ag; Au
Other commodities Cu
Ore minerals bornite; chalcopyrite; chrysocolla; gold; malachite; pyrite; unidentified silver-bearing sulfosalt
Gangue minerals amethyst; quartz

Geographic location

Quadrangle map, 1:250,000-scale IL
Quadrangle map, 1:63,360-scale A-6
Latitude 59.1067
Longitude -154.8793
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Pfaff (Battle Lake) prospect is at an elevation of about 2,600 feet about 3.5 miles due east of the north end of Battle Lake. It is in the NW1/4 SW1/4 sec. 29, T. 12 S., R. 33 W., Seward Meridian. The location is accurate within about 0.5 mile. The prospect is number 18 of Detterman and Cobb (1972) and number 16 of Detterman and Reed (1980, fig. 6). The prospect is in Katmai National Park.

Geologic setting

Geologic description

The country rocks at this prospect are Tertiary dacite and interbedded tuff and volcanic breccia (Detterman and Reed, 1980). About 0.5 mile northwest of the prospect, the dacite and fragmental units are overlain by Tertiary andesite and basalt.
The deposit consists of north-striking, quartz-sulfide veins that cut propylitically-altered flows, tuff, and breccia (Detterman and Reed, 1980). The veins range from a few inches to more than 6 feet thick, and can be traced through outcrops and pits for about 1,000 feet. Locally, the veins comprise quartz-cemented breccia of intensely altered andesite or dacite; the quartz is vuggy and some of the cavities are lined with amethyst crystals (C. C. Hawley, examination notes and samples, 1986). The veins locally contain abundant chalcopyrite, pyrite, and an unidentified silver-bearing sulfosalt; some copper-rich parts of the veins contain abundant disseminated free gold (collection of prospector Ray Gatz, circa 1970).
Hawley tentatively identified bornite during his site visit in 1986. Sulfide-rich veins are locally oxidized to malachite and chrysocolla(?). Selected samples collected by Detterman and Reed (1980) contained 0.41 to 36.4 ounces of gold per ton and 6.6 to 168.8 ounces of silver per ton. Copper content ranged from almost nil in quartz-rich veins to several percent in sulfide-rich veins. The property was drilled by its owners in 1965; according to Detterman and Reed (1980), results of the drilling were not encouraging.
Geologic map unit (-154.88141397703, 59.106006647882)
Mineral deposit model Creede-type epithermal vein (Cox and Singer, 1986, model 25b).
Mineral deposit model number 25b
Age of mineralization Tertiary.
Alteration of deposit Propylitically-altered volcanic breccia and dacitic flows; silicification; local argillic alteration. Oxidation of copper.

Production and reserves

Workings or exploration The property was discovered by Ernie Pfaff in about 1964, and the owners of the claims drilled a few diamond core holes in 1965. Pfaff continued to prospect with cuts and trenches until about 1980. Essentially no work was done after the prospect area was included in Katmai National Park, and the claims were allowed to lapse after Pfaff's death.
Indication of production None
Production notes High-grade specimens of gold ore were collected at the site and some, such as those in the collection owned by prospector Ray Gatz, may have been sold.

Additional comments

Detterman and Reed (1980, p. B79) suggested that: 'This area of Tertiary volcanic and intrusive rocks warrants further prospecting and geochemical sampling for precious and base-metal deposits.' Such work is unlikely in the near term, however, because the prospect is in Katmai National Park.

References