Smith Lake

Prospect, Active

Alternative names

BMP

Commodities and mineralogy

Main commodities Ag; Cu; Pb; Zn
Other commodities Bi; Co
Ore minerals chalcopyrite; galena; pyrite; pyrrhotite; sphalerite
Gangue minerals clinopyroxene; siderite

Geographic location

Quadrangle map, 1:250,000-scale MG
Quadrangle map, 1:63,360-scale B-2
Latitude 62.3279
Longitude -153.7404
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Smith Lake prospect is about 150 meters west of the outlet of Smith Lake and 120 meters upstream from the junction of a small unnamed tributary and the Smith Lake fork of Sheep Creek. It is at an elevation of 3,000 feet in the SW1/4 sec. 21, T. 26 N., R. 24 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description

The mineralization at the Smith Lake prospect consists of a high angle, sulfide-rich fault zone in mid-Silurian clastic rocks of the Terra Cotta Sandstone, a unit of the Dillinger sub-terrane (Bundtzen, Harris, and Gilbert, 1997). The fault zone trends N45E, dips steeply to vertically, and is from 0.5 to one meter wide. An adit driven into the mineralized zone exposed about 8 meters of the sulfide vein along its strike.
The main ore mineral is pyrrhotite which makes up 75 percent of the sulfides; minor amounts of pyrite, chalcopyrite, galena, and sphalerite are associated with the pyrrhotite. The gangue material includes significant secondary siderite and highly deformed clinopyroxene. Selected chip samples contained up to 1.05 percent copper, 1.74 percent lead, 5.22 percent zinc, 42.0 grams of silver per tonne, 100 parts per million (ppm) cobalt, and 100 ppm bismuth (Bundtzen, Kline, and Clough, 1982; Smith and Albanese, 1985). A 0.3-meter-long channel sample collected by Brewer and others (1992) contained 14.8 percent lead, 10.6 percent zinc, 0.6 percent copper, and 90.2 grams of silver per tonne. The Smith Lake mineralization is typical of other silver-polymetallic prospects in Farewell Mineral Belt.
In 2008, this prospect was one of several in a block of claims that covered more than 70 square miles, known collectively as the BMP project (International Tower Hill Mines, Ltd., 2008).
Geologic map unit (-153.742622651232, 62.3272884325903)
Mineral deposit model Polymetallic veins (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Alteration of deposit Siderite alteration.

Production and reserves

Workings or exploration Some time prior to 1980, an 8-meter-long adit was driven into this sulfide-rich fault zone. It has been sampled several times by government and industry geologists from the early 80s into the 1990s. As of 2008, the prospect was within a large block of claims called the BMP project by International Tower Hill MIne, Ltd. (2008).
Indication of production None

References