|Quadrangle map, 1:250,000-scale||CY|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Fourth of July Creek is a northeast-flowing tributary of the Yukon River. Its confluence with the Yukon is near the town of Nation. Placer mining and exploration took place along the entire creek, which is about 16 miles long. Coordinates given are for the approximate center of the placer ground, which is in section 35, T. 4 N., R. 28 E., of the Fairbanks Meridian. The location is accurate.|
The upper basin of Fourth of July Creek lies in Cretaceous to Tertiary sandstone, mudstone, and conglomerate derived from erosion of older metamorphic rocks (Dover and Miyaoka, 1988). The conglomerate is auriferous and probably is the source of all or most of the placer gold in Fourth of July Creek (Brooks, 1907). The placers immediately downstream from the upper basin also are underlain by conglomerate and other sedimentary rocks. The bench deposits on the northwest side of the valley are also auriferous but were not mined (Mertie, 1938). Platinum metals and silver are alloyed with the gold; a report of mercury is unverified. The mean of 22 assays of the gold indicates the average fineness is 892 parts Au per thousand, 99 parts Ag per thousand, and 9 parts dross per thousand. In 1942, one gold specimen assayed 0.23 percent platinum and iridium, with a trace of palladium (Mertie, 1938).The first claims along Fourth of July Creek were staked in 1898, and within 10 days most of the creek had been staked (National Park Service, 1990). There were about ten miners left working on the creek in 1904, and six in 1906. Production between 1898 and 1906 was between $25,000 and $30,000 (1906 dollars) (National Park Service, 1990). A hydraulic plant was installed along the creek in 1916 (Brooks, 1918). In 1938, the pay streak was reported to be 400 to 500 feet wide, and the bedrock was overlain by 6 to 10 feet of gravel and 2 to 7 feet of muck. The gold was mainly found on and in the top 2 feet of bedrock (Mertie, 1938). The last year that productive mining was done on the creek was 1951. Mining ended due to high production costs (National Park Service, 1990).
|Geologic map unit||(-141.981354002711, 65.1366949333704)|
|Mineral deposit model||Placer Au (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary.|
|Workings or exploration||Discovery of gold at Fourth of July Creek was in 1898, and since then mining and exploration were nearly continuous until 1973 (Cobb, 1976 [OFR 76-632]). Most mining was by hydraulic methods, and the first hydraulic plant was installed in 1916 (Brooks, 1918). In 1941, the Fourth of July Creek operation was the largest in the Eagle district (Smith, 1942).|
|Indication of production||Yes; medium|
|Production notes||Production between 1898 and 1906 was between $25,000 and $30,000 (1906 dollars) (National Park Service, 1990).|
Additional commentsThis site is within the Yukon-Charley Rivers National Preserve.
|MRDS Number||A015241; M045827|
Brooks, A.H., 1907, The Alaskan mining industry in 1906: U.S. Geological Survey Bulletin 314-A, p. 19-39.
Chapin, Theodore, 1914, Placer mining in the Yukon-Tanana region: U.S. Geological Survey Bulletin 592-J, p. 357-362.
Cobb, E.H., 1972, Metallic mineral resources map of the Charley River quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-390, 1 sheet, scale 1:250,000.
Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Charley River and Coleen quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-632, 45 p.
Dover, J.A., and Miyaoka, R.T., 1988, Reinterpreted geologic map and fossil data, Charley River quadrangle, east-central Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-2004, 2 sheets, scale 1:250,000.
Ellsworth, C.E., and Davenport, R.W., 1913, Placer mining in the Yukon-Tanana region: U.S. Geological Survey Bulletin 542-F, p. 203-222.
Koschmann, A.H., and Bergendahl, M.H., 1968, Principal gold producing districts of the United States: U.S. Geological Survey Professional Paper 610, 283 p.
Mertie, J.B., Jr., 1938, Gold placers of the Fortymile, Eagle, and Circle districts, Alaska: U.S. Geological Survey Bulletin 897-C, p. 133-261.
Mertie, J.B., Jr., 1942, Tertiary deposits of the Eagle-Circle district, Alaska: U.S. Geological Survey Bulletin 917-D, p. 213-264.
Mertie, J.B., Jr., 1969, Economic geology of platinum minerals: U.S. Geological Survey Professional Paper 630, 120 p.
National Park Service, 1990, Final environmental impact statement, volume 1, Mining in Yukon-Charley Rivers National Preserve, Alaska: National Park Service, Anchorage, Alaska, p. 36-44.
Prindle, L.M., and Mertie, J.B., Jr., 1912, Gold placers between Woodchopper and Fourth of July Creeks, upper Yukon River: U.S. Geological Survey Bulletin 520-G, p. 201-210.
|Reporters||C.E. Cameron (ADGGS)|
|Last report date||4/7/2000|