Eagle River

Prospect, Inactive

Alternative names

Mayflower

Commodities and mineralogy

Main commodities Ag; Au; Cu; Pb; Zn
Ore minerals argentiferous galena; arsenopyrite; chalcopyrite; gold; malachite; pyrite; sphalerite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale AN
Quadrangle map, 1:63,360-scale A-6
Latitude 61.13
Longitude -149.09
Nearby scientific data Find additional scientific data near this location
Location and accuracy Prospect located near the south bank of Eagle River, 4,500 ft west-northwest of the terminus of Eagle Glacier. Accurate within 2,000 ft. Locality 7 on plate 33 of Park (1933), locality 51 of Cobb (1972), and locality 40 of MacKevett and Holloway (1977).

Geologic setting

Geologic description

Mineralized quartz veins in fine-grained, massive metagraywacke of the Late Cretaceous Valdez Group. The host rock shows sheared zones that strike N 5 W and are vertical or dip about 65 NW. Several large interbedded conglomerate lenses and minor argillite are present within the graywacke. Mineralized quartz veins that are less than 1 ft thick and that can be traced for 400 ft, are found in two sheared zones 50 ft apart (Park, 1933). Quartz veins contain galena, pyrite, sphalerite, arsenopyrite, chalcopyrite, and limited malachite. Assays show 0.05 oz/ton Au and 10 to 25 oz/ton Ag (Park, 1933). Calcite veinlets found in joints of graywacke (Martin and others, 1915). The most conspicuous quartz vein can be traced south of the river and probably is also exposed to the north of Eagle River.
Geologic map unit (-149.09219995551, 61.1294433376686)
Mineral deposit model Low-sulfide Au-quartz veins? (Cox and Singer, 1986; model 36a?) or Chugach-type low-sulfide Au-quartz vein? (Bliss, 1992; model 36a.1?) or Polymetallic veins? (Cox and Singer, 1986; model 22c?).
Mineral deposit model number 36a, 36a.1, 22c
Age of mineralization Late Cretaceous or younger; the veins cut Late Cretaceous Valdez Group rocks.
Alteration of deposit Oxidation of Cu minerals.

Production and reserves

Workings or exploration Assays show 0.05 oz/ton Au and 10 to 25 oz/ton Ag (Park, 1933). Limited amount of work on prospect by 1933. Smith (1938) reported prospecting in 1936, a vein opened by a few open cuts with apparently encouraging results. By 1951 the prospect could not be found (White, 1952).
Indication of production None

Additional comments

Property originally known as the Mayflower lode (Park, 1933).

References

MRDS Number A011652

References

Reporters D.P. Bickerstaff (USGS contractor); S.W. Huss (USGS)
Last report date 7/30/1998