|Quadrangle map, 1:250,000-scale||NM|
|Quadrangle map, 1:63,360-scale||C-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Rock Creek is a southwest-flowing tributary of Snake River with headwaters on the south flank of Mount Brynteson. Placer workings are present along about 1.5 miles of Rock Creek; the approximate midpoint of the workings are in the NW1/4 section 23, T. 10 S., R. 34 W., Kateel River Meridian. The most extensive deposits were developed between elevations of about 200 to 350 feet. The location is the approximate discovery point (Francisco Placer, U.S. Mineral Survey No. 721) of the placer deposit. It is locality 98 of Cobb (1972 [MF 463], 1978 [OFR 78-93]).|
Geologic descriptionThe main Rock Creek placer deposit is an alluvial placer developed in the flood plain of modern Rock Creek. The deposit was discovered by Lindeberg, Lindblom, and Brynetson in the fall of 1898 within a few days or weeks of the discovery of the Anvil Creek placer (NM236). Rock Creek was visited by the U.S. Geological Survey in 1903 (Collier and others, 1908). At that time, one company, presumably the Pioneer Mining Company, was working on five claims. Gold was distributed throughout pay gravel that was only about 5 feet deep. The gold was mainly fine with a few rough nuggets. Semiangular scheelite occurred in the concentrates along with magnetite, limonite, and garnet. The part of the deposit in the main Rock Creek flood plain was as much as 300 feet wide on the No. 4 Above claim and an adjacent west bench claim. It was relatively shallow, about 5 to 12 feet deep, and was developed on hard schist bedrock where indentations and irregularities acted as riffles. This placer deposit was largely worked out by 1905, probably by hand shovel-in and scraper operations. A series of hydraulic pits on the east side of Rock Creek above Sophie Gulch appears to be on a residual placer developed on the main Rock Creek sheeted vein complex (NM207). This part of the placer may have been developed somewhat later, as was the residual scheelite-rich placer mined in Sophie Gulch in 1916 and 1917 (NM208). Cathcart (1920) reported mining on Rock Creek in 1918; Smith (1926) reported mining in 1924. Scheelite reportedly was mined in 1943 (Anderson, 1947). Thorne and others (1948) reported scheelite along the main 1.5 mile length of the Rock Creek placer. Coats (1944) believed that Rock Creek was one of the more important scheelite-bearing creeks in the Nome area. In general, it is difficult to distinguish between descriptions of mining along Rock Creek and that along the more limited Sophie Gulch deposit. Total production from the Rock Creek placer has been estimated to be about 30,000 ounces of gold.
|Geologic map unit||(-165.419807287393, 64.6109345247345)|
|Mineral deposit model||Alluvial placer Au (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary.|
|Workings or exploration||The placer deposit in Rock Creek was discovered in the fall of 1898 by the pioneers of the Nome district, Jafet Lindeberg, Erik O. Lindblom, and John Brynetson. The discovery claim was named Francisco. Claims extended upstream to the 6 Above claim, about at the confluence with Albion Creek. By 1905, the date of the patent survey, a placer deposit as much as 300 feet wide had been worked continuously from the Francisco claim to the 5 Above claim in the main flood plain of Rock Creek. An east side residual placer appears to have been worked in a series of hydraulic pits above Sophie Gulch. When the claims were patented in 1906, the value of improvements reported by the Pioneer Mining Company was in excess of 300,000 dollars. Estimated total production was about 30,000 ounces of gold. Metcalfe and Tuck (1942) thought that there was sufficient pay left, probably mainly in a buried bench channel (NM210), to justify a small dragline operation at Rock Creek.|
|Indication of production||Yes|
|Production notes||Estimated total production was about 30,000 ounces of gold.|
Anderson, Eskil, 1947, Mineral occurrences other than gold deposits in northwestern Alaska: Alaska Territorial Division of Mines Pamphlet 5-R, 48 p.
Cathcart, S.H., 1920, Mining in northwestern Alaska: U.S. Geological Survey Bulletin 712-G, p. 185-198.
Cathcart, S.H., 1922, Metalliferous lodes in southern Seward Peninsula: U.S. Geological Survey Bulletin 722-F, p. 163-261.
Coats, R.R., 1944, Lode scheelite occurrences of the Nome area: U.S. Geological Survey Open-File Report 17, 6 p.
Cobb, E.H., 1972, Metallic mineral resources map of the Nome quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-463, 2 sheets, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Nome quadrangle, Alaska: U.S. Geological Survey Open-File report 78-93, 213 p.
Collier, A.J., Hess, F.L., Smith, P.S., and Brooks, A.H., 1908, The gold placers of parts of Seward Peninsula, Alaska, including the Nome, Council, Kougarok, Port Clarence, and Goodhope precincts: U.S. Geological Survey Bulletin 328, 343 p.
Mertie, J.B., Jr., 1918, Placer mining on Seward Peninsula in Brooks, A.H., and others, Mineral resources of Alaska, report on progress of investigations in 1916: U.S. Geological Survey Bulletin 662, p. 451-458.
Metcalfe, J.B., and Tuck, Ralph, 1942, Placer gold deposits of the Nome district, Alaska: Report for U.S. Smelting, Refining, and Mining Co., 175 p.
Moffit, F.H., 1913, Geology of the Nome and Grand Central quadrangles, Alaska: U.S. Geological Survey Bulletin 533, 140 p.
Smith, P.S., 1926, Mineral industry of Alaska in 1924: U.S. Geological Survey Bulletin 783-A, p. 1-30.
|Reporters||C.C. Hawley and Travis L. Hudson|
|Last report date||7/10/2000|