Unnamed (northeast of Mirror Lake)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale IL
Quadrangle map, 1:63,360-scale A-5
Latitude 59.2389
Longitude -154.7059
Nearby scientific data Find additional scientific data near this location
Location and accuracy This approximately located occurrence is at an elevation of about 2,250 feet approximately 1.5 miles northeast of the east end of Mirror Lake. It is near the center of sec. 8, T. 11 S., R. 32 W., Seward Meridian. The location is uncertain; it is based on a description by Mather (1925, p. 172), which correlates fairly well with the geology mapped by Detterman and Reed (1980). The lccation is probably accurate within about 1 mile. Mather (1925) also noted mineral deposits closer to the east end of Mirror Lake.

Geologic setting

Geologic description

The country rocks at this site are mainly Tertiary volcanic strata that rest unconformably on Jurassic granodiorite that underlies much of the headwater area of Funnel Creek above Mirror Lake (Detterman and Reed, 1980). The granodiorite has a lobe-like western projection into the head of Mirror Lake. Mather (1925) believed that the granodiorite intrudes the Tertiary volcanic rocks, but it probably intrudes only nearby Jurassic or older rocks (Detterman and Reed, 1980).
The volcanic rocks at this occurrence reportedly are cut by abundant quartz-pyrite veins as much as several inches thick (Mather, 1925). Nearer Mirror Lake, and exposed in small creeks flowing into the lake, a swarm of pyrite- and chalcopyrite-bearing quartz veins as much as a half-mile across is in the Jurassic granodiorite and its metamorphic country rocks (Mather, 1925).
Geologic map unit (-154.70803165726, 59.238209902042)
Mineral deposit model Uncertain. Possibly polymetallic veins or porphyry copper (Cox and Singer, 1986, models 22c and 17).
Mineral deposit model number 22c?, 17?
Age of mineralization The veins in the volcanic rocks are Tertiary; the veins in the granodiorite and metasedimentary rocks are Jurassic or younger.

Production and reserves

Workings or exploration No claims or workings are reported.
Indication of production None

References