Synneva (Scynneva) Creek

Mine, Probably inactive

Commodities and mineralogy

Main commodities Au
Other commodities Sn; W
Ore minerals cassiterite; gold; scheelite

Geographic location

Quadrangle map, 1:250,000-scale LC
Quadrangle map, 1:63,360-scale C-5
Latitude 60.708
Longitude -154.703
Nearby scientific data Find additional scientific data near this location
Location and accuracy Locality is a 215 m long cut along Synneva Creek, about 270 m upstream from confluence of Bonanza Creek and Synneva Creek. This is part of locality 7 Nelson and others (1985) and locality 7 of Cobb (1972). SE1/4SW1/4 sec. 10, T. 7 N., R. 31 W., of the Seward Meridian. Locality is accurate to within 100 m.

Geologic setting

Geologic description

Synneva (Scynneva) Creek is a placer gold deposit. Analysis of heavy concentrates yield 60 percent cassiterite and 1.36 percent tungsten (Eakins and others, 1978). Jasper (1961) reported: evidence indicates that glacial scouring was not an important erosional factor in this area, it is believed that pre-glacial alluvials were undisturbed, and that placer gold concentrations remain more or less as originally deposited along the creek. The valley alluvials are mostly uniform gravels with some boulders, interpreted as reworked glacial deposits. Bedrock is shale, argillite, and graywacke cut by porphyritic granitic dikes. The sediments strike N 40 to 45 E, and dip varies from 60 to 75 SW.
Geologic map unit (-154.705257414242, 60.7073229073945)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a)
Mineral deposit model number 39a
Age of mineralization Quaternary.
Alteration of deposit Not applicable

Production and reserves

Workings or exploration
Work began in about 1957, and was limited to hand methods (ground-sluice and shovel-in). One man worked the mouth of the narrow gulch moving about 800 to 900 cubic yards, from which an unconfirmed $1,200 was recovered. There was no evidence to indicate that bedrock had been reached (Jasper, 1961).
Analysis of heavy concentrates yield 60 percent cassiterite and 1.36 percent tungsten (Eakins and others, 1978).
Indication of production Yes; small
Reserve estimates No reserves
Production notes Jasper (1961) mentioned about 35 oz Au production, but probably much more was unreported (Eakins and others, 1978).

Additional comments

Essentially part of the Bonanza Creek placer deposit.

References

MRDS Number A013004

References

Reporters M.L. Miller (USGS); D.P. Bickerstaff (USGS)
Last report date 6/15/1998