Unnamed (lode in lower Rock Creek)

Occurrence, Probably inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; W
Ore minerals arsenopyrite; gold; pyrite; scheelite
Gangue minerals albite; quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale C-1
Latitude 64.6052
Longitude -165.432
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on the southeast side of Rock Creek, about 600 feet upstream of the Snake River road crossing. Rock Creek is an east tributary to Snake River with headwaters on the south flank of Mount Byrnteson. The map location is just inside the west-central border of section 23, T. 10 S., R. 34 W., Kateel River Meridian. It is locality 30 of Hummel (1962 [MF 247]) locality 24 of Hummel (1962 [MF 243]) is also included here.

Geologic setting

Geologic description

A massive quartz vein, as much as 4 feet wide, is exposed on the southeast side of Rock Creek about 600 feet upstream of the Snake River road (Hummel, 1962 [MF 247, locality 30]). Exposures on the south bank of Rock Creek between the quartz vein and the road locally also contain pyrite-arsenopyrite-bearing quartz veins (Hummel, 1962 [MF 247, locality 24]). These occurrences are separated from numerous other mineral deposits in the Rock Creek area by the Mount Brynteson fault. Hummel (1962 [MF 247]) mapped this nearly north-striking fault about one-half mile west of Mount Brynteson. The fault apparently continues southward to the Snake River flood plain. It also appears to have controlled the course of strongly linear Bergstrom Gulch. Hummel (1962 [MF 247]) reported the presence of gold and scheelite; arsenopyrite and pyrite are also present. Kennecott Exploration Company drilled two shallow reverse circulation holes in this area in 1994 or 1995 but found only low gold values.
Geologic map unit (-165.434604617082, 64.6044338210287)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization Mid-Cretaceous; veins cross cut regionally metamorphosed schist; see NM207.
Alteration of deposit Albitization and silicification.

Production and reserves

Workings or exploration Quartz veins and sulfidized schist were explored by trenches and shallow shafts probably before 1920. Two prospects in the area between the Mount Brynetson fault and the Glacier Creek road were noted by Hummel (1962, localities 24 and 30). The area was soil sampled by BHP in 1989; it is within the extensive arsenic-gold anomaly that extends almost continuously from Glacier Creek to north of Lindblom Creek. Kennecott Exploration Company drilled two reconnaissance reverse circulation holes in this area in 1995 but found only low gold values.
Indication of production Undetermined

References