Dome Creek; Little Miller Creek Mines, Fortymile District, Southeast Fairbanks Borough, Alaska, USA

Location: Dome Creek is a 15-mile-long west tributary of O'Brien Creek; it is about 7 miles south of Liberty (on the Taylor Highway). Little Miller Creek is a small tributary of Dome Creek. Placer gold along Dome Creek is found in bench gravels that extend 4 miles upstream from Little Miller Creek and 2 miles downstream (Mertie, 1938). The mines' coordinates are at the mouth of Little Miller Creek, in section 16, T. 6 S., R. 33 E., of the Fairbanks Meridian; the location is accurate. References to Little Miller Creek are grouped with those of Dome Creek. There is another Dome Creek (EA055) in the Eagle C-1 Quadrangle. Dome Creek is locality 34 of Burleigh and Lear (1994), locality 22 of Eberlein and others (1977), and locality 70 of Cobb (1972 [MF-393]).
Geology: The rocks in the vicinity of Dome Creek are Paleozoic amphibolite-facies gneiss, amphibolite, quartzite, schist, marble, and greenschist (Foster, 1976). Bedrock exposed in placer cuts on the benches along Dome Creek consists of quartzite, schist, serpentinized greenstone, and marble (Mertie, 1938). The bedrock is cut by shear zones filled with greenish gouge, some of which contains granulated vein quartz with pyrite. Quaternary terrace and colluvial deposits are extensive in the vicinity of the Dome and Little Miller Creek placer deposits. Gold was discovered on Dome Creek at the mouth of Little Miller Creek in 1893 (Prindle, 1905). Placer gold along Dome Creek is predominantly found within bench gravels that extend 4 miles upstream from Little Miller Creek and at least 2 miles downstream (Mertie, 1938). Most of the bench gravels are found on the north side of Dome Creek, approximately 125 feet above the level of the creek. The bench gravels are about 300 feet wide. Little Miller Creek cuts across the Dome Creek bench gravels, and the active stream has reconcentrated the gold. As a result, the stream placers mined near the mouth of Little Miller Creek were very high grade. Most of the bench mining on Dome Creek occurred downstream from Little Miller Creek because the bench gravels increase in thickness upstream. Gravel in Little Miller Creek is about 8 feet thick. The pay streak occurs near bedrock in about 10 inches of gravel over a width of 20 feet (Prindle, 1905). The gold is mostly coarse and rough, but a few smooth pieces were found as well. The gold-bearing bench gravels adjacent to Little Miller Creek are as much as 80 feet thick (Mertie, 1938). In 1928, bench gravels were being mined about 1.5 miles downstream from Little Miller Creek on the north bench of Dome Creek (Mertie, 1930 [B 813-C]). The gravels were as much as 80 feet thick; they are overlain by a muck layer that contains the remains of mammoth, bison and other ancient vertebrates of Pleistocene age. The placer gold on the bench is fairly porous, particularly in the larger pieces, and it contains abundant quartz (Mertie, 1930 [B 813-C]). The placer gold is mainly found near or on bedrock, but fine gold is disseminated throughout the 80 feet of bench gravel. The gold is bright yellow and mostly fin small pieces. Placer concentrates contain minor galena and cinnabar and abundant pyrite. An average of two assays of gold indicated that it has a fineness of 885 parts of gold per thousand and 107 parts of silver per thousand (Mertie, 1938). The bedrock consists of schist and marble, and the schist is cut by quartz seams (veins?) that contain pyrite and arsenopyrite; (see EA078) (Mertie, 1930 [B 813-C]). One cleanup from the high bench gravel on the west side of Little Miller Creek yielded $27,000 at an average value of 35 cents per square foot of bedrock, or about 14 cents per cubic yard of gravel (gold at $20.67 per ounce). In 1930, the gold was worth about $18.50 to $18.75 an ounce (Mertie, 1930 [B 813-C]). The earliest mining on Dome Creek occurred near the mouth of Little Miller Creek where gold was first discovered in 1893 (Prindle, 1905). Mining and prospecting on Dome Creek took place intermittently between 1893 and perhaps as late as 1920, when it was mostly mined out. Bench mining started in 1919 near Little Miller Creek and progressed westward. A large hydraulic plant mined the bench gravels (Brooks and Martin, 1921). Mining activity continued from 1937 through 1940 (Smith, 1942 [B 933-A]). In 1990, Dome Creek Mining and Development sluiced on Dome Creek at an unreported location (Swainbank and others, 1991).
Workings: The earliest mining on Dome Creek occurred near the mouth of Little Miller Creek where gold was first discovered in 1893 (Prindle, 1905). Mining and prospecting on the creek took place intermittently between 1893 and perhaps as late as 1920, when it was mined out. Bench mining started in 1919 near Little Miller Creek and progressed westward. A large hydraulic plant mined the bench gravels (Brooks and Martin, 1921). Mining activity continued from 1937 through 1940 (Smith, 1942 [B 933-A]). In 1977, there was a small mining operation at the mouth of Dome Creek; it had been active for several years (Eberlein and others, 1977). In 1990, Dome Creek Mining and Development sluiced on Dome Creek at an unreported location (Swainbank and others, 1991).
Age: Quaternary.
Production: One cleanup from the high bench gravel on the west side of Little Miller Creek yielded $27,000 at an average value of 35 cents to the square foot of bedrock, or about 14 cents per cubic yard of gravel (gold at $20.67 per ounce). In 1930, the gold was worth about $18.50 to $18.75 an ounce (Mertie, 1930).

Commodities (Major) - Au; (Minor) - Hg, Pb
Development Status: Yes
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a).

Mineral List

4 entries listed. 4 valid minerals.

References