Misty Mountain

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Hg
Ore minerals arsenopyrite; gold
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale UN
Quadrangle map, 1:63,360-scale C-2
Latitude 53.8776
Longitude -166.4418
Nearby scientific data Find additional scientific data near this location
Location and accuracy Locality is southeast of Summer Bay lake and is accurate.

Geologic setting

Geologic description

This occurrence is primarily a very high (more than 40 colors per pan) gold pan concentrate anomaly. Country rocks are strongly propylitically altered andesitic tuffs and flows capped by unaltered basaltic volcanic rocks. The andesitic rocks host a wide-spaced cockscomb quartz vein system containing rare arsenopyrite. 'The veining appears to be controlled by several shear zones that developed in response to large-scale faulting (Randolph, 1991).' Battle Mountain Exploration considered source of pan concentrate anomaly indeterminate as their fieldwork was unable to delineate a source. A ridge to the north of the occurrence hosts several wide-spaced quartz vein systems; however, sampling did not locate highly anomalous areas.
Geologic map unit (-166.44369758688, 53.8767389707234)
Mineral deposit model Epithermal gold vein
Mineral deposit model number 25
Age of mineralization Late Tertiary or younger
Alteration of deposit Regional propylitic alteration; no apparent wall-rock alteration around vein.

Production and reserves

Workings or exploration Pan concentrate, rock, and soil sampling by BMEC. Rock sampling was of andesitic rocks cut by quartz veins in the stream basin. Highest gold from these rocks was 168 ppb, pan concentrate from the basin yielded 170 ppb Au and 930 ppb Hg.
Indication of production None

References

MRDS Number A106006

References

Randolph, D.B., 1991, Unalaska project, 1990 final report: Battle Mountain Exploration Company, Alaska District, 62 p., 5 appendices, 15 plates, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reporters F.H. Wilson
Last report date 12/18/1992