Intermediate Beach

Mine, Inactive

Alternative names

Clam Shell Beach

Commodities and mineralogy

Main commodities Au
Ore minerals arsenopyrite; gold; ilmenite; magnetite; pyrite
Gangue minerals garnet

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale C-1
Latitude 64.5213
Longitude -165.3919
Nearby scientific data Find additional scientific data near this location
Location and accuracy Intermediate Beach is a buried marine placer gold deposit on the Nome coastal plain about 1.5 miles inland from the modern beach at Nome. It is in an area where surface elevations are about 100 feet, and it extends, probably discontinuously, from west of Bourbon Creek about 3 miles southeast to Otter Creek. It was extensively placer mined over a half mile section northwest of Bourbon Creek. The map location is the approximate midpoint of this half mile section, in the west-central part of section 24, T. 10 S., R. 34 W., Kateel River Meridian. Intermediate Beach is locality 143 of Cobb (1972 [MF 463], 1978 [OFR 78-93]).

Geologic setting

Geologic description

Intermediate Beach is a buried marine abrasion platform placer deposit as much as several hundred feet wide. The gravel is 6 to 12 feet thick, with 1-3 feet of pay gravel on bedrock. The elevation of the deposit is about 20 feet above sea level. Depth of burial is about 20 to 60 feet (Moffit, 1913; Nelson and Hopkins, 1972).
The deposit terminates abruptly to the west. It appears to diminish in grade to the east at about Bourbon Creek, but it may continue eastward as a low-grade deposit through the head of Peluk Creek and lower parts of Otter and Florence Creeks (Metcalfe and Tuck, 1942, p. 36). The pay gravel contained abundant fragments of graphitic schist; locally, clam shells were so abundant that it was called the Clam Shell beach (Moffit, 1913, p. 118). The clams (mollusks) included species now living off Japan and some that only live south of present winter ice in the Bering Sea. Dall concluded that the climate in Intermediate Beach time was warmer than now at Nome (Dall, in Moffit, 1913, p. 45). Intermediate Beach appears to have formed when marine currents lowered an auriferous platform during a Pleistocene transgression that formed Third Beach.
Intermediate Beach was discovered in the winter of 1905-1906 (Smith, 1908; Moffit, 1913). The deposit was dredged extensively between Center and Bourbon Creeks after the development of cold-water thawing. (Center Creek is not named on the 1970 edition of the topographic map but is probably the drainage paralleling the northeast runway of the Nome airport.)
Geologic map unit (-165.394495244017, 64.5205335271776)
Mineral deposit model Marine gold placer deposit; marine abrasion platform concentration (Cox and Singer, 1986; model 39).
Mineral deposit model number 39

Production and reserves

Workings or exploration The deposit was drift mined after 1906. After the development of cold-water thawing in the 1920s, it was dredged, especially between Bourbon and Center Creeks.
Indication of production Yes

References