|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||
Four main gold-bearing beaches, Present Beach (NM255), Second Beach (NM256), Third Beach (NM258), and locally preserved Fourth Beach (NM259), constitute true strandline gold placer deposits of the Nome coastal plain; they are developed between Cape Nome and Cape Rodney. Present Beach is essentially continuous throughout this distance, the Second beach is almost continuous, and Third Beach is discontinuous. Discontinuous deposits such as Intermediate (NM287), Monroeville (NM-257) Submarine Beach (NM285), and Center Creek (NM286), occur in the same general area, but fthey ormed on submarine abrasion platforms offshore of the strandline deposits. The map location is the approximate center of the area of all onshore marine and beach deposits. It is in the NW1/4 section 24, T. 11 S., R. 34 W., Kateel River Meridian.The deposits described in this record are essentially the same as the Nome Beaches of Cobb (1978 [OFR 78-93, p. 119-124]). Cobb's Nome Beaches category includes locality numbers 129, 135, 137-139, and 141-143 of Cobb (1972 [MF 463]). Note that location 138 has been described previously (NM251).
Three main strandline beach deposits exist at Nome, Present (also First or Modern), Second, and Third. With reference to modern sea level, these beaches formed, respectively, at current sea level, 38 feet and about 70 feet in elevation. There is some evidence of a fourth beach at an elevation of 120 feet, and there appear to be other fossil beachlines under the sea. The other so-called beaches (Monroeville, Intermediate, Submarine, and Center Creek) appear to have developed offshore on the seaward abrasion platforms of the beaches. The following general descriptions are largely based on Metcalfe and Tuck (1942).
Present Beach extends from Cape Nome to Cape Rodney. It was auriferous throughout, but it was richest near Nome. It formed by reworking marine sedimentary deposits that range from about 10 feet to more than 100 feet in thickness. Gold was characteristically very fine grained and commonly had to be saved by amalgamation. It occurred mainly in lens-like concentrations. Garnet was abundant, black sand less so.
Second Beach is nearly continuous, but interrupted by stream erosion at Penny River, Snake River, Nome River, and Hastings Creek. It has an average elevation of about 38 feet and occurred from a few hundred feet to 3,000 feet inland of Present Beach. Second Beach also formed mainly by reworking marine sediment. At Nome and near Snake and Penny Rivers, Second Beach appears to have formed on sand spits. West of Hastings Creek and at other places, this beach formed as the sea was encroaching on headlands composed of marine sediments. Most of the gold in Second Beach deposits, except near Otter Creek, was fine grained.
The highly productive Third Beach is discontinuous and is complex in origin. To the east of Nome near Hastings Creek, it apparently formed in an environment of lagoons and barrier bars and is not well developed or very productive. Near Irene and Cunningham Creeks and from Macdonald to near Little Creeks, it formed as a narrow strandline deposit against gravel headlands. It has been removed by erosion on Snake River, but it exists near Sunset Creek in the Nome C-2 quadrangle; it is productive only in a small area. Third Beach is present, but has not been productive, west of Sunset Creek.Some other beach-like deposits, specifically the Intermediate, Monroeville, Submarine, and Center Creek deposits, appear to have formed in an offshore abrading environment as the sea advanced onto the shoreline. Sulfides, principally pyrite and arsenopyrite, are much more abundant in platform than in the strandline deposits. The lens-shaped beach deposits of gold in garnet or black sand characteristic of the strandline beaches are not well developed in the abrading marine environment. In general, gold in the marine abrasion platforms is coarser than in the strandline deposits. Several of the deposits have complex origins. The richest part of Submarine Beach could have formed near the mouth of ancestral Anvil Creek (Metcalfe and Tuck, 1942).
|Geologic map unit||(-165.389697016869, 64.5251338364045)|
|Mineral deposit model||Lensoid deposits of fine gold associated with black and ruby sands in the true beach strandlines; disseminated and crudely stratabound concentrations formed in an offshore abrading environment.|
|Age of mineralization||Late Pliocene and Pleistocene.|
|Workings or exploration||
Gold was discovered on Present Beach in 1899 and immediately gave rise to extensive production. Second Beach was discovered in 1902 and Third Beach was discover in 1904. In 1906, Nome had its most productive year when more than 295,000 ounces of gold were produced (Bundtzen and others, 1994). The Intermediate Beach was discovered in 1906 and Submarine Beach in 1907. By 1908, the richest parts of the beaches were worked out, but major production continued in the abrasion areas seaward from the true beaches.In general, production from the submerged deposits was by drift-mining and by large-scale hydraulic operations, until the development of cold-water thawing in the 1920s. The first two large dredges and thaw-fields were installed in 1923 (Brooks, 1925, p. 49). Extensive development by dredging did not take place until about 1930 as defects were worked out of the thawing process. The great dredging era was from about 1927 (Smith, 1930 [B 810]) until World War II (Smith, 1942). Dredges were reactivated after World War II and operated until about 1965. Two dredges operated after 1975 in the Dry Creek and Submarine Beach areas (Kastelic, 1975). From 1996 until 1998 all operations were truck-shovel open pits, with summertime washing.
|Indication of production||Yes; large|
|Reserve estimates||Resources locally remain in the remnants of the beach and abrasion deposits that have not been previously mined.|
|Production notes||Most of the production of the Nome district (NM250) has come from the strandline deposits and their related offshore abrasion deposits.|
Brooks, A.H., 1925, Alaska's mineral resources and production, 1923: U.S. Geological Survey Bulletin 773-A, p. 3-52.
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.
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.
Kastelic, W.R., 1975, Gold placer exploration, Nome, Alaska: Colorado Mining Association, 1975 Mining Yearbook, p. 85-90.
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.
Smith, P.S., 1930, Mineral industry of Alaska in 1927 and Administrative Report: U.S. Geological Survey Bulletin 810-A, p. 1-64.
|Reporters||C.C. Hawley and Travis L. Hudson|
|Last report date||7/10/2000|