Unnamed (near Bonanza Creek)

Prospect, Inactive

Commodities and mineralogy

Main commodities Au
Ore minerals arsenopyrite; gold
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale D-7
Latitude 60.8268
Longitude -149.5253
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is located in the SW1/4 section 31, T. 9 N., R. 1 W., of the Seward Meridian. It is at an elevation of 2,000 feet, on the southwest side of Bonanza Creek. This is location 18 of Cobb and Tysdal (1980). The location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The principal deposit at this prospect consists of auriferous, sulfide-bearing quartz-calcite veins that heal fractures in a 3-foot-wide Eocene(?) felsic dike (Kenai Star dike; see SR022) (Tuck, 1933). The veins make up about 2 percent of the dike, which strikes N30E and dips 45 to 60 E. and intrudes slate and sandstone of the Valdez Group of Late Cretaceous age (Tuck, 1933; Tysdal, 1978 [MF-880-A]). Thin quartz-calcite-cemented fractures in the slate and sandstone have 2.5- to 5-inch-wide sericitic alteration envelopes (Tysdal, 1978 [MF-880-A]). There is little alteration near the larger quartz veins. The deposit was explored by a 69-foot adit. A sample of mineralized dike yielded a small amount of arsenopyrite and a trace of gold.
Geologic map unit (-149.527464457862, 60.8262316558084)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Eocene(?) or younger; the veins heal fractures in an Eocene(?) dike.
Alteration of deposit Quartz-calcite-filled hairline fractures in the slate and sandstone are bordered by sericitic alteration envelopes 2.5 to 5 inches wide.

Production and reserves

Workings or exploration Underground workings consist of one 69-foot adit (Tysdal, 1978 [MF-880-A]).
Indication of production None

Additional comments

The felsic dike at this prospect probably is an extension of the Kenai Star dike (SR022). Mitchell (1979) examined the area in 1977. The results of his work are not included in this record.

References