|Quadrangle map, 1:250,000-scale||NM|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This site is in Cooper Gulch on the south side of Anvil Mountain. The site includes alluvial placer gold deposits in upper and lower Cooper Gulch and a calcite lode in upper Cooper Gulch (Cathcart, 1922, figure 18, location 1). The map location is about half way up the gulch from the inland margin of the coastal plain and just inside the north boundary of section 12, T. 11 S., R. 34 W., Kateel River Meridian. This is locality 103 of Cobb (1972 [MF 463], 1978 [OFR 78-93]).|
Upper Cooper Gulch was placer mined by rocker and hydraulic methods and produced a small amount of gold between 1900 and 1916 (Cobb, 1978 [OFR 78-93]). A small area near a bench where the gulch merges with the coastal plain apparently yielded good returns in gold (Moffit, 1913). Unconsolidated materials included 8 to 10 feet of low-grade gravel below 1 to 4 feet of overburden. Boulders in hydraulic tailings were mostly marble along with some greenstone and granite (Collier and others, 1908). Bedrock is mostly marble and schist that probably are of early Paleozoic protolith age (Hummel, 1962 [MF 247]; Till and Dumoulin, 1984; Bundtzen and others, 1994).
An ancestral Cooper Gulch may have been the source of gold on Fourth Beach (NM249) into shallow alluvial deposits on the coastal plain. Moffit (1913, p. 123-124) thought the lower Cooper Gulch deposit unusual enough to classify it as a 'gravel-plain placer'. The gold on lower Cooper Gulch mainly lay on clay streaks but also was distributed throughout the section. The deposit may have been a fan or delta from ancestral Cooper Gulch into the Third Beach sea.The M. Charles lode was also reported from near the head of Cooper Gulch on the west side (Cathcart, 1922, figure 18, location 1). A short tunnel on the west bank of Cooper Gulch follows a fault zone about 4 feet wide containing brecciated schist replaced by ferruginous calcite; there is abundant limonite but no evidence of gold. Cathcart (1922) inferred the former existence of sulfide minerals from the limonite.
|Geologic map unit||(-165.383102638353, 64.5552347388106)|
|Mineral deposit model||Alluvial placer Au (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary.|
|Workings or exploration||One hydraulic pit was 100 by 300 feet in size in 1903 (Collier and others, 1908). An attempt was made to mine the lower Cooper Creek deposit by dredging (Moffit, 1913). Upper Cooper Gulch was mined by hand methods.|
|Indication of production||Yes; small|
Bundtzen, T.K., Reger, R.D., Laird, G.M., Pinney, D.S., Clautice, K.H., Liss, S.A., and Cruse, G.R., 1994, Progress report on the geology and mineral resources of the Nome mining district: Alaska Division of Geological and Geophysical Surveys, Public Data-File 94-39, 21 p., 2 sheets, scale 1:63,360.
Cathcart, S.H., 1922, Metalliferous lodes in southern Seward Peninsula: U.S. Geological Survey Bulletin 722-F, p. 163-261.
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.
Hummel, C.L., 1962, Preliminary geologic map of the Nome C-1 quadrangle, Seward Peninsula, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-247, 1 sheet, scale 1:63,360.
Moffit, F.H., 1913, Geology of the Nome and Grand Central quadrangles, Alaska: U.S. Geological Survey Bulletin 533, 140 p.
Till, A.B., and Dumoulin, J.A, 1994, Geology of Seward Peninsula and St. Lawrence Island, in Plafker, G., and Berg, H.C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, v. G-1, p. 141-152.
|Reporters||C.C. Hawley and Travis L. Hudson|
|Last report date||7/10/2000|