East Vein

Prospect, Inactive

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale HE
Quadrangle map, 1:63,360-scale A-6
Latitude 63.216
Longitude -149.643
Nearby scientific data Find additional scientific data near this location
Location and accuracy The East Vein prospect is at an elevation of about 3,400 feet in and adjacent to Bryn Mawr Creek. The site is in sec. 3, T. 20 S., R. 11 W., of the Fairbanks Meridian. The location is accurate to within 400 feet.

Geologic setting

Geologic description

The country rocks at the East Vein prospect are hornfelsed Triassic red-bed sedimentary strata. The deposit is a quartz stringer lode that strikes N 30 E, dips steeply to the northwest, and has a strike length of over 1,000 feet. The lode ranges from 1 to 3 feet wide and contains discontinuous pods of arsenopyrite, chalcopyrite, galena, pyrite, and sphalerite. In Bryn Mawr Creek the vein contains up to 80 percent sulfides. In places, the vein is in gradational contact with country rock. Sulfide composition varies over short distances from arsenopyrite-rich to galena-sphalerite-rich zones. Vein samples assayed 0.01-0.90 ounce of gold per ton, 1.2-8.5 ounces of silver per ton, 0.15-0.73 percent copper, up to 1.8 percent lead, and up to 17 percent zinc (Mulligan and others, 1967). The East Vein prospect is about 500 feet east-northeast of the Golden Zone mine (HE043), and probably is an extension of that deposit.
Geologic map unit (-149.645291542539, 63.2155261564423)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c)
Mineral deposit model number 22c
Age of mineralization Probably Late Cretaceous.
Alteration of deposit The alteration is probably similar to that described for the adjacent Golden Zone and BLT, which consists of sericite, ankerite and quartz.

Production and reserves

Workings or exploration All surface exploration. Vein samples assayed 0.01-0.90 ounce of gold per ton, 1.2-8.5 ounces of silver per ton, 0.15-0.73 percent copper, up to 1.8 percent lead, and up to 17 percent zinc (Mulligan and others, 1967).
Indication of production None

References