Lake

Mine, Probably inactive

Alternative names

Margery Group

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale PE
Quadrangle map, 1:63,360-scale B-1
Latitude 56.4737
Longitude -132.0958
Nearby scientific data Find additional scientific data near this location
Location and accuracy The location of this mine as shown in Gault and others (1953). It is about two miles east of the east end of Virginia Lake at an elevation of about 1,450 feet and about 0.5 mile southeast of the center of section 23, T. 62 S., R. 86 E. The location is accurate.

Geologic setting

Geologic description

The Lake mine was first staked in 1905 as the Margery claims and by 1908 was exposed in several open cuts and short tunnels (Wright and Wright, 1905, 1908). One ton of ore was shipped in 1920 (Gault and others, 1953). It was still active in 1925 when it was restaked as the Lake claims and was active until at least 1927 (Buddington, 1926, Smith 1930a, Smith 1930b). It was restaked in 1965 and then again in 1978 by the Pacific Coast Molybdenum Co. who held the claims until 1986 (Still and others, 2002). The workings consist of three adits, numerous trenches, and surface stripping; most probably date to before 1927.
The mineralization occurs along a major fault zone that strikes N25 to 35 E and dips 70 to 90 degrees to the southeast (Gault and others, 1953; Still and others, 2002) The rocks in the vicinity are dark-colored phyllite and slate, quartzite, chlorite schist, and biotite schist that are about 2000 feet west of large Cretaceous biotite tonalite to granodiorite pluton (Gault and others, 1953; Brew, 1997). The fault zone is 5 to 12 feet wide and has been exposed in the adits and numerous trenches and pits for about 1,450 feet. The mineralization is all within the fault zone and consists of quartz breccia with major galena and lesser sphalerite, pyrite, and chalcopyrite, as well as as massive sulfide bands up to 0.5 feet thick, and sulfide-bearing quartz veinlets and pods.
Still and others (2002) collected several samples. A sample in a narrow vein of galena and sphalerite in Adit 1 (of Gault and others, 1953) contained 161 parts per million (ppm) silver, 8.54 percent lead, and 2.10 percent zinc. A 4.6-foot sample across the face of Adit 2 contained 10.3 ppm silver, 1.058 percent lead, and 1.3 percent zinc; a select dump sample from this adit contained 4.73 ounces of silver per ton, 10.5 percent lead, and 6.60 percent zinc. Still and others also sampled several trenches and pits; the samples contained 178 to 411 ppm silver, 2,049 to 3,266 ppm copper, 7.89 to 25.1 percent lead, and 3.60 to 16.4 percent zinc.
Geologic map unit (-132.097482889514, 56.4733654402692)
Mineral deposit model Sulfide-bearing quartz breccia along a regional fault.

Production and reserves

Workings or exploration The Lake mine was first staked in 1905 as the Margery claims and by 1908 was exposed in several open cuts and short tunnels (Wright and Wright, 1905, 1908). One ton of ore was shipped in 1921 (Gault and others, 1953); It was still active in 1925 when it was restaked as the Lake claims and was active until at least 1927 (Buddington, 1926, Smith 1930a, Smith 1930b). It was restaked in 1965 and again in 1978 by the Pacific Coast Molybdenum Co. who held the claims until 1986 (Still and others, 2002). The workings consist of three adits, numerous trenches, and surface stripping; most probably date to before 1927.
Indication of production Yes; small
Reserve estimates None.
Production notes One ton of ore shipped to smelter in 1920 (Gault and others, 1953).

References

MRDS Number A01030

References

Still, J.C., Bittenbender, P.E., Bean, K.W., and Gensler, E.G., 2002, Mineral assessment of the Stikine area, central southeast Alaska: Bureau of Land Management Technical Report 51, 560 p.
U.S. Bureau of Mines, 1980, Claim map, Petersburg quadrangle, Alaska: U.S. Bureau of Mines Map 117, 1 sheet, scale 1:250,000.
Reporters H. C. Berg (Fullerton, California); D.J. Grybeck (Port Ludlow, WA)
Last report date 3/4/2008