Bowser Creek-Northeast

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Pb; Zn
Other commodities Cu; Fe
Ore minerals chalcopyrite; galena; pyrrhotite; sphalerite (marmatite)
Gangue minerals chlorite; clinopyroxene (hedenbergite); epidote

Geographic location

Quadrangle map, 1:250,000-scale MG
Quadrangle map, 1:63,360-scale A-2
Latitude 62.191
Longitude -153.69
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Bowser Creek-Northeast prospect is located on a steep, north-trending spur on the north side of Bowser Creek valley; it is at an elevation of 4,700 feet to 5,100 feet (1,432 to 1,554 meters) in sec. 4, T. 24 N., R. 24 W., of the Seward Meridian. The prospect is precisely known; the reporter visited the site in 1982.

Geologic setting

Geologic description

The Bowser Creek-Northeast prospect is a north-trending, elongate mineral zone that averages 7 meters wide and about 300 meters long near a small body of quartz porphyry and related felsite dikes, which are satellite intrusions of the main Bowser Creek composite pluton (Bundtzen and others, 1988). The plutonic rocks intrude a limestone-rich section of the Dillinger subterrane (Bundtzen, Harris, and Gilbert, 1997); host rocks at the Bowser Creek Northeast prospect are Late Silurian to Lower Devonian in age. A prospect map was published by Reed and Elliott (1968, C 559).
According to Reed and Elliott (1968, C 559), the skarn typically consists of pyrrhotite and marmatite (iron-rich sphalerite) with abundant epidote, chlorite, clinopyroxene (hedenbergite), and quartz. Disseminated galena occurs in shear zones related to dike swarm activity.
Reed and Elliott (1968, C 559) reported values from chip sample traverses as high as 357.7 grams/tonne silver, 3.4 grams/ton gold, 2.44 percent copper, 24.00 percent lead, and 22.10 percent zinc. According to Bundtzen and others (1988), the average metallic content of several 5 meter chip samples taken across the the mineralized zone was 0.35 grams/tonne gold, 244.0 grams/tonne silver, 821 ppm copper, 12.13 percent lead, and 11.13 percent zinc.
Geologic map unit (-153.69222407161, 62.1903840055522)
Mineral deposit model Lead-zinc skarn (Cox and Singer, 1986; model 18c).
Mineral deposit model number 18c
Age of mineralization Inferred to be Tertiary, based on a 60.4 Ma K-Ar age from quartz porphyry in the Bowser Creek pluton.
Alteration of deposit Extensive ferricrete oxidation of pyrrhotite and marmatite-rich sulfide zones.

Production and reserves

Workings or exploration
The Bowser Creek-Northeast prospect was found by the late Bruce Reed during minerals investigations for the U.S. Geological Survey in the 1960s (Reed and Elliott, 1968, C 596). Reed and Elliott (1968, C 559) reported values from chip sample traverses as high as 357.7 grams/tonne silver, 3.4 grams/tonne gold, 2.44 percent copper, 24.00 percent lead, and 22.10 percent zinc. According to Bundtzen and others (1988), the average metallic content of several 5 meter chip samples taken across the mineralized zone was 0.35 grams/tonne gold, 244.0 grams/tonne silver, 821 ppm copper, 12.13 percent lead, and 11.13 percent zinc.
No surface trenching or drilling have been conducted on the property.
Indication of production None
Reserve estimates None.

Additional comments

Part of a series of low temperature zinc-lead-silver skarns associated with Bowser Creek composite pluton (see MG066, MG068 prospects).

References