|Quadrangle map, 1:250,000-scale||CY|
|Quadrangle map, 1:63,360-scale||B-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Colorado Creek is a northeast-flowing tributary of Coal Creek, which is a northeast-flowing tributary of the Yukon River. Colorado Creek joins Coal Creek just south of the major placer activity on Coal Creek (CY006). Colorado Creek is about 7 miles long; coordinates for the mines have been arbitrarily placed at the approximate midpoint of the creek, in the NE1/4 section 19, T. 5 N., R. 22 E., of the Fairbanks Meridian. The exact location along Colorado Creek where mining was conducted is uncertain, although the lower section of Colorado Creek seems most likely. The location is accurate to within 4 miles.|
In 1905, Colorado Creek was the location of most mining activity in the Coal Creek valley (Prindle, 1906). There is an unconfirmed report of the discovery of a galena-bearing quartz vein (Brooks, 1907). The exact location along Colorado Creek where mining was conducted is uncertain, although the lower Colorado Creek seems most likely.
The bedrock at the head of Colorado Creek is Paleozoic phyllitic argillite. The creek crosses a fault, and the lower portion of the creek flows over Tertiary to Cretaceous sedimentary rocks (Dover and Miyaoka, 1988). As at Fourth of July Creek (CY015), Coal Creek (CY006), and Woodchopper Creek (CY038), the source of gold is probably gravels derived from Tertiary conglomerate.Mining took place along Colorado Creek intermittently between 1905 and 1946. Nuggets as large as half an ounce were found. The reported production from Colorado Creek in 1946 was 49 troy ounces of gold and 1 troy ounce of silver (National Park Service, 1990).
|Geologic map unit||(-143.302396271969, 65.299664508195)|
|Mineral deposit model||Placer Au (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary?|
|Workings or exploration||Mining took place along Colorado Creek intermittently between 1905 and 1946. Nuggets as large as half an ounce were found (National Park Service, 1990).|
|Indication of production||Yes; small|
|Production notes||The reported production from Colorado Creek in 1946 was 49 troy ounces of gold and 1 troy ounce of silver (National Park Service, 1990).|
Additional commentsSee also Coal Creek (CY006) and Boulder Creek (CY004). This site is within the Yukon-Charley Rivers National Preserve.
Brooks, A.H., 1907, The Alaskan mining industry in 1906: U.S. Geological Survey Bulletin 314-A, p. 19-39.
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.
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.
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.
|Reporters||C.E. Cameron (ADGGS)|
|Last report date||4/7/2000|