Crevice Creek Mine, Koyukuk Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Crevice Creek Mine	Mine
Koyukuk Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: Crevice Creek is a west-flowing tributary to John River; it is between McCamant Creek to the north and Bullrun Creek to the south. The mouth of Crevice Creek is approximately 0.5 mile south of the junction of the John and Allen Rivers. The center of the placer workings is about 3.5 miles upstream of the mouth of Crevice Creek, approximately at the eastern side of section 12, T. 29 N., R. 20 W., of the Fairbanks Meridian. The workings extend for about two miles upstream and downstream. The location is accurate.
Geology: Although he did not visit Crevice Creek in 1937, Reed (1938) noted that Crevice Creek flowed principally on bedrock and that the gold that was mined from potholes and crevices in the bedrock. Some of the gold-bearing crevices were several feet deep. Dillon (1982) mapped the rocks in the area as a schist-marble unit, and tentatively identified stibnite in the placer concentrates. Occasional native silver nuggets have been recovered with the gold (Kurtak and others, 2002). Panned-concentrate samples from Crevice Creek contain visible gold grains and abundant magnetite; a sample from a sluice-box concentrate has over 8,000 ppb gold (Kurtak and others, 1999). Bliss and others (1988) speculate that the gold is derived from sulfide-bearing quartz veins in the Devonian Skajit limestone (see WI066). Analyses of seven gold samples from Crevice Creek gave median values of 4.2% silver, 0.14% copper, 0.008% lead, and 0.47% mercury, and a median fineness of 958. Three of these analyses showed detectable levels (but less than 2 ppm) of Pd (Mosier and Lewis, 1986). Mining was reported as early as 1904 and the property was sluice mined in the 1980's (Bliss and others, 1988). The last year of significant mining on the creek was in 1994, followed by only minor suction dredging on the lower creek in 1998 (Kurtak and others, 2002). Approximately $1,800 in gold (at $20.67 per ounce) was said to have been produced in 1904 (Maddren, 1913). Dillon (1982) reports production of 30 ounces of gold per year, but it is unclear whether this production was historical or current as of 1982.
Workings: Mining was reported as early as 1904 and the property was sluice mined in the 1980's (Bliss and others, 1988). The last year of significant mining on the creek was in 1994, followed by only minor suction dredging on the lower creek in 1998 (Kurtak and others, 2002).
Age: Quaternary.
Production: Approximately $1,800 in gold (at $20.67 per ounce) was said to have been produced in 1904 (Maddren, 1913). Dillon (1982) reports production of 30 ounces of gold per year, but it is unclear whether this production was historical or current as of 1982.

Commodities (Major) - Au; (Minor) - Ag, Sb(?)
Development Status: Yes
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a)

Other Databases

Link to USGS - Alaska:	WI064

Other Regions, Features and Areas containing this locality

References