Quartz Creek

Mine, Active

Commodities and mineralogy

Main commodities Au
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale C-7
Latitude 60.545
Longitude -149.6141
Nearby scientific data Find additional scientific data near this location
Location and accuracy Quartz Creek is located in T. 5 and 6 N., R. 2 W., of the Seward Meridian. The map site representing this gold placer mine is in the NW1/4 section 10, T. 5 N., R. 2 W. of the Seward Meridian. This is location 31 of Cobb and Richter (1972), location 172 of MacKevett and Holloway (1977), location 23 of Cobb and Tysdal (1980), and location P-81 of Jansons and others (1984). This location is accurate to within 300 feet.

Geologic setting

Geologic description

Quartz Creek drains an area underlain by slate and graywacke of the Valdez Group of Late Cretaceous age (Nelson and others, 1985).
Quartz Creek is about 16 miles long and drains into Kenai Lake. Upper Quartz Creek (east of the Seward Highway) occupies a steep, narrow, avalanche-debris-filled valley partially cut into bedrock. An alluvial fan has developed between the mouth of the canyon and about mile 42 of the Seward Highway. The alluvial fan deposits are poorly washed and stratified; fine gold is distributed throughout the deposits but is concentrated on bedrock. Gold as much as one-eighth inch in diameter has been recovered (Jansons and others, 1984).
The remainder of Quartz Creek occupies a broader, more gentle valley, with a bedrock canyon along a half-mile stretch above Devils Creek. Bedrock crops out in many places in this canyon where interbedded slate and graywacke strike N17W and dip 60W (Johnson, 1912). The character of the unconsolidated material covering the bedrock is shown in a ditch that extends along the east side of the valley. It consists of compact clay-matrix gravel that contains a few, waterworn, rounded and striated boulders. Small, gravel-covered benches are at different elevations on the canyon sides and along the stream course. High-grade channel and bench deposits have been successfully mined in this part of the canyon.
The bench gravels are locally stratified and typically compacted. They have a high clay content and commonly contain boulders as large as 3 feet in diameter (Jansons and others, 1984). Bench gravels, containing rounded slate and sandstone boulders and varying in thickness from 12 to 22 feet due to the undulating bedrock surface, were mined in 1911. The bench gravels yielded $0.26 to $0.32 per cubic yard, when gold was worth $20.67 per troy ounce (Johnson 1912). The gold is mostly flakes, and nuggets coarser than one-quarter inch in diameter are rare.
The creek gravels are reported to carry coarse gold and to have paid well (Johnson, 1912).
Geologic map unit (-149.616259258962, 60.5444334740823)
Mineral deposit model Placer Au (alluvial) (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary.

Production and reserves

Workings or exploration
In 1911, a hydraulic plant operated on Quartz Creek a short distance above the mouth of Devils Creek (Johnson, 1912). In this portion of its course, Quartz Creek winds southward in a narrow, steep-sided canyon cut in the bedrock floor of a broad glaciated valley. The plant obtained water from Quartz Creek a short distance below the mouth of Johns Creek by a 1.5-mile-long ditch with a grade of one-fourth of an inch to the rod (Johnson, 1912). The intake was situated on the west bank of the creek, and the ditch follows the west side of the valley to a point about one-half mile below the intake, where the water was carried across Quartz Creek on a 160-foot flume. The pipeline from the penstock to the giants decreased gradually from 14 inches to 10 inches at the giant. Two No. 2 Kendall giants with No. 3 nozzles operated under heads of 95 to 120 feet. The gold-saving apparatus consisted of 10 sluice boxes. Most of the gold was captured in the first two boxes. Ten men were at work in early 1911; later this force was much reduced (Johnson, 1912).
On upper Quartz Creek, pits and trenches were dug in the early 1900s and in the 1950s and 1960s (Jansons and others, 1984).
In the early 1980s the U.S. Bureau of Mines collected two samples from upper Quartz Creek that assayed 0.0024 and 0.0384 ounce of gold per cubic yard (Jansons and others, 1984). They also collected several samples of untested bench gravels, which contained a trace to 0.0024 ounces of gold per cubic yard. One sample of mine-run gravels contained 0.0384 ounce of gold per cubic yard as averaged through 4 feet of gravel resting on bedrock.
From 1971 to the present (2000), small-scale sluicing and dredging have occurred in and above the canyon of Quartz Creek (C.S. Huber, oral communication, 2000).
Indication of production Yes; small
Reserve estimates Jansons and others (1984) estimate that there are more than 750,000 cubic yards of bench and channel gravels between Devils Creek and Johns Creek.
Production notes The U.S. Bureau of Mines estimated production at 1,000 ounces of gold, of which as much as 400 ounces have been produced since 1975 (Jansons and others, 1984). The U.S. Bureau of Mines estimated less than 25 ounces of gold have been produced from upper Quartz Creek.

References

References

Hoekzema, R.P., and Sherman, G.E., 1983, Mineral investigations in the Chugach National Forest, Alaska (Peninsula study area): U.S. Bureau of Mines in-house report; held at U.S. Bureau of Land Management Alaska State Office, Anchorage, 524 p.
Reporters Jeff A. Huber (Anchorage)
Last report date 7/5/2000