Unnamed (lower Boulder Creek)

Prospect, Inactive

Commodities and mineralogy

Main commodities Au
Ore minerals gold; limonite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale C-1
Latitude 64.6441
Longitude -165.4953
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of about 175 feet on lower Boulder Creek, a west tributary to Snake River. The prospect is near the edge of the Snake River flood plain and about 6,000 feet upstream from the mouth of Boulder Creek. The map location is at the southwest corner of section 4, T. 10 S., R. 34 W., Kateel River Meridian. It is included in locality 94 of Cobb (1972 [MF 463], 1978 [OFR 78-93]).

Geologic setting

Geologic description

Auriferous quartz veins near the mouth of Boulder Creek were reported to contain 0.15 to 0.20 ounce of gold per ton (Collier and others, 1908, p. 196). Mertie (1918) reported a gold-bearing quartz vein in the bed of Boulder Creek on placer claim No. 1 Below Discovery; it was in a fault zone from which free gold could be panned. Examination of this area in 1991 located a lode prospect on the north side of Boulder Creek about 800 feet upstream from the downstream limit of patented mining claims. At this point, a short adit had been driven northeast on a limonite-stained quartz vein (Kennecott Exploration Company, written communication, 1992). The limonite probably replaced pyrite. No free gold was observed, but a sample of the vein contained about 0.1 ounce of gold per ton.
Geologic map unit (-165.497907215813, 64.6433327177832)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization Mid-Cretaceous or younger; postdates regional metamorphism of the host rocks.

Production and reserves

Workings or exploration A short adit, now caved, was driven northeast on an iron-stained quartz vein. This may be the same prospect as that reported by Collier and others (1908).
Indication of production Undetermined