Unnamed (west shore of Nichols Bay)

Occurrences, Probably inactive

Commodities and mineralogy

Main commodities Zn
Other commodities Ag
Ore minerals pyrite; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale DE
Quadrangle map, 1:63,360-scale C-1
Latitude 54.7071
Longitude -132.1228
Nearby scientific data Find additional scientific data near this location
Location and accuracy This site represents two geologically similar occurrences along the west shoreline of Nichols Bay about 1.6 and 2.0 miles north-northwest of Point Nunez. One is near the center of section 4, T. 83 S., R. 89 E. The other, at the coordinates, is about at the center of the north boundary of the same section.

Geologic setting

Geologic description

This site, first described by Gehrels and others (1983), represents two occurrences, about a half mile apart, in Silurian or Ordovician (Descon Formation) strata (Gehrels, 1992). The northern occurrence consists of several centimeter-thick, pyrite-rich layers in fragmental silicic volcanic rocks. Samples contained up to 0.5 parts per million (ppm) silver and 140 ppm zinc. The 10-meter-wide unit that contains the pyrite-rich layers may extend to the southern occurrence. The southern occurrence consists of several 2- to 6-centimeter-thick lenses that contain much pyrite and microscopic sphalerite, in locally fragmental, silicic volcanic rocks. The mineralized rock is interbedded with andesitic pillow breccia and massive flows; andesite dikes cut the mineralized lenses. Samples contained up to 0.7 ppm silver and 140 ppm zinc.
Geologic map unit (-132.124463809436, 54.7067616112902)
Mineral deposit model Kuroko massive sulfide (Cox and Singer, 1986; model 28a).
Mineral deposit model number 28a
Age of mineralization The massive-sulfide layers are contemporaneous with the deposition of the Silurian or Ordovician Descon Formation.

Production and reserves

Workings or exploration Only outcrop sampling.
Indication of production None

References