Lucky Day

Mine, Undetermined

Commodities and mineralogy

Main commodities Hg; Sb
Ore minerals cinnabar; mercury; pyrite; stibnite
Gangue minerals carbonate; dickite; limonite; quartz

Geographic location

Quadrangle map, 1:250,000-scale TA
Quadrangle map, 1:63,360-scale C-8
Latitude 60.75
Longitude -158.85
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Lucky Day mine is on the divide between the headwaters of locally named Canary Gulch and Cinnabar Creek (TA002), a west tributary to Beaver Creek. The map site is at an elevation of about 1,850 feet, near the west end of the boundary between sections 25 and 36, T 8 N, R 55 W, of the Seward Meridian. The mine is 1.5 miles west of the north end of the Beaver Creek airstrip. It is locality 3 of Cobb (1972 [MF 384]; 1976 [OF 76-606]).

Geologic setting

Geologic description

The Lucky Day mine area includes cinnabar- and stibnite-bearing deposits along the west side of upper Canary Gulch and at the divide between Canary Gulch and Cinnabar Creek (Rutledge, 1050). During WWII, 3,600 pounds of cinnabar-rich materials recovered from residual colluvial deposits at the head of Canary Gulch yielded 26 flasks of mercury (Rutledge, 1950, p. 4; Cady and others, 1955, p. 114). The lode deposits are in sedimentary and igneous rocks inferred to be part of a Paleozoic and Mesozoic sedimentary and volcanic sequence; several Triassic fossil localities are in the Cinnabar Creek area about 3 miles north of the Lucky Day mine (Sainsbury and MacKevett, 1965).
The Lucky Day mine area has been explored by many surface pits, dozer trenches, and shallow shafts (Rutledge, 1950; Cady, 1955). In the 50-foot wide and 350-foot long mineralized zone along the west side of upper Canary Gulch, cinnabar, quartz, and stibnite form thin and sparse films along bedding plane faults, fractures, and joints, and occur as fillings between graywacke and shale fragments in breccia; some native mercury is also present (Rutledge, 1950). Three samples of the highest grade material in this zone respectively contained 0.31, 0.18 and 0.07 percent Hg and 0.16, 0.19, and 0.15 percent Sb (Rutledge, 1950, p. 6). Seven samples collected from this zone by the owners contained a trace to 0.10 percent Hg (Rutledge, 1950, p. 6).
Mineralization on the divide between Canary Gulch and Cinnabar Creek is localized along and near the faulted contact of an altered, approximately 10-foot wide mafic dike or sill. The mafic intrusive body is almost parallel to bedding in the enclosing graywacke and siltstone, which strikes N 5-10 W and dips moderately west (Sainsbury and MacKevett, 1965). The mineralized zone is along the west contact of the mafic intrusive; it is about 900 feet long, 50 feet wide, and exposed over a vertical distance of about 130 feet (Rutledge, 1950; Cady and others, 1955; Sainsbury and MacKevett, 1965). High-grade mineralization within this zone consists of discontinuous, massive, cinnabar veins and lenses, averaging about 1 inch thick, along the intrusive contact and in narrow offshoots along bedding plane faults in structurally overlying graywacke. Cinnabar is accompanied by quartz, stibnite, dickite, limonite, and some native mercury. Eight samples from this zone contained 0.14 to 15.7 percent Hg and 0.32 to 3.0 percent Sb (Rutledge, 1950, fig. 5). Hawley and others (1969) reported that two ore samples respectively contained 70.10 and 35.87 percent Hg, 0.008 and 0.05 ppm Au, 1,500 and 700 ppm Zn, and greater than 10,000 and 300 ppm Sb. The graywacke, siltstone, and mafic intrusive country rocks are variably altered and replaced by quartz, carbonate, and clay minerals; some pyrite is present in the altered mafic intrusive rocks but it has not been observed in association with cinnabar.
Geologic map unit (-158.852272417777, 60.7492781779983)
Mineral deposit model Cinnabar- and stibnite-bearing veins (Hot-spring Hg? Cox and Singer, 1986; model 27a)
Mineral deposit model number 27a
Age of mineralization Cretaceous or Tertiary. Inferred to be similar in age to other mercury deposits of southwest Alaska that postdate deposition of mid-Cretaceous clastic sedimentary rocks and intrusion of Upper Cretaceous or Tertiary igneous rocks.
Alteration of deposit Variable quartz-carbonate-clay alteration of graywacke, siltstone, and mafic intrusive country rock.

Production and reserves

Workings or exploration The Lucky Day mine area has been explored by many surface pits, dozer trenches, and shallow shafts (Rutledge, 1950; Cady, 1955).
Indication of production Yes; small
Production notes During WWII, 3,600 pounds of cinnabar-rich materials recovered from residual colluvial deposits at the head of Canary Gulch yielded 26 flasks of mercury (Rutledge, 1950, p. 4; Cady and others, 1955, p. 114). The recovered ore was transported to Sleetmute by backpacking and boat. It was retorted at the Red Devil mine in 1942-43.

References