Myers Fork Mine, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Myers Fork Mine	Mine
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: Myers Fork is a small creek about a mile north of Chicken that drains southeast into Chicken Creek. Placer tailings on Myers Fork are shown on the U.S. Geological Survey 1:63,360-scale topographic map of the Eagle A-2 quadrangle (1956; revised in 1971). The coordinates for this mine correspond to the approximate midpoint of these tailings in section 29, T. 27 N., R. 18 E., of the Copper River Meridian; the location is accurate. This site is locality 77 and 80 of Burleigh and Lear (1994), locality 43 of Eberlein and others (1977), and locality 51 of Cobb (1972 [MF-393]).
Geology: Myers Fork, a tributary of Chicken Creek, flows through a high-angle-fault bounded, structurally down-dropped basin that preserves a wedge of Tertiary gabbro and sedimentary rocks (Werdon and others, 2001). Intra-basin, high-angle faults are rarely exposed in outcrop but are inferred from the distribution of the geologic units, stratigraphic relations, and airborne resistivity and magnetic data (Alaska Division of Geological and Geophysical Surveys and others, 1999). The structural basin is bounded to the south and east by the Taylor Mountain batholith of Triassic age and to the north and west by upper Paleozoic greenschist-facies metasedimentary and metavolcanic rocks (Foster, 1969); Werdon and others, 2001). In the headwaters of Myers Fork, the upper Paleozoic metamorphic rocks are in high-angle fault contact with the Chicken pluton of Jurassic age to the north. Quaternary alluvium and colluvium deposits are extensive within the Myers Fork area and Chicken Creek valley. They largely consist of gravel and lesser silt and sand overlain by muck. Placer mining of the sedimentary deposits in Chicken Creek (see EA128) has exposed numerous Pleistocene mammalian fossils, including mammoth, horse, caribou, and bison (Pinney, 2001). Many Quaternary terrace gravel benches of possible glaciofluvial origin occur up to 600 feet above the creek (Pinney, 2001). Along Myers Fork, at least four bedrock benches are recognized below the stream gravels. Near the lower part of Myers Fork, the alluvium is as much as 15 feet thick, and silt and muck over it is about 11 feet thick (Mertie, 1938). Most of the gold on the east side of the creek occurs on top of a clay- and silt-rich layer and in fine gravels just below it, a few inches above bedrock. Very little gold is present within or on top of bedrock. The gold is not coarse, but one 1.5-ounce nugget was found. The fineness of gold mined from benches from 1925 to 1935 ranged from 827 to 842 parts of gold per thousand and from 148 to 171 parts of silver per thousand (Mertie, 1938). The average gold fineness was 833 parts of gold per thousand and 160 parts of silver per thousand. The fineness of gold from a high bench on the southwest side of Myers Fork was 819 parts of gold per thousand and 176 parts of silver per thousand. Placer concentrates contain mostly magnetite and ilmenite, as well as minor garnet, barite, scheelite, and zircon. A potential source for placer gold in Myers Fork is the Purdy lode gold prospect (EA121), which is located on the ridge just north of the creek. Myers Fork has been mined by drifting, sluicing, bulldozer, and hydraulic methods. Placer gold was produced from about 1903 to at least 1940, and intermittently in the 1970's. Two hydraulic plants were operating on Myers Fork in 1936 (Mertie, 1938). The estimated value of the cut that was mined in 1936 is about 30 cents to the square foot of bedrock (Mertie, 1938). In 1990, there was an active placer mine on Myers Fork (Yeend, 1992).
Workings: Myers Fork has been mined by drifting, sluicing, bulldozer, and hydraulic methods. Placer gold was produced from about 1903 to at least 1940 and intermittently in the 1970's. Two hydraulic plants were operating on Myers Fork in 1936 (Mertie, 1938).
Age: Quaternary.
Production: The estimated value of the cut that was mined in 1936 is about 30 cents to the square foot of bedrock (Mertie, 1938). Production in 1904-1907 that included that from Myers Fork (EA124), Lost Chicken Creek (EA131), Stonehouse Creek (EA122), and Ingle Creek (EA111) totaled about 18,835 fine ounces (Eberlein and others, 1977).

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

Other Databases

Link to USGS - Alaska:	EA124

Other Regions, Features and Areas containing this locality

References