Lady of the Lake

Prospect, Undetermined

Alternative names

Lucky Boy
North Vein
Complex
Frisco
Idaho
Minnetonka
Oregon
Portland
Seattle

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale CR
Quadrangle map, 1:63,360-scale A-1
Latitude 55.15756
Longitude -132.236
Nearby scientific data Find additional scientific data near this location
Location and accuracy The workings at the Lady of the Lake prospect extend from the shore of upper Dora Lake to an elevation of about 330 feet. They are about 0.3 mile northeast of the southern tip of the lake and about 0.5 mile south of the center of section 25, T. 77 S, R. 87 E. Several authors combine their descriptions of this prospect with the Lucky Boy propect (CR174), about 0.4 mile to the southwest. For example, Roppel (1991), who focuses on the personalities and early history of the properties, describes both prospects under the name 'Complex' (which was the name of a short-lived post office and one of the many names for the claim groups that covered both prospects). Robinson and Twenhofel (1953) call the prospect at this site the 'Lucky Boy North deposit,' and the Lucky Boy prospect, the 'Lucky Boy South deposit.' Maas and others (1991) follow Robinson and Twenhofel's nomenclature, whereas Maas and others (1995) call this site the Lady of the Lake prospect and the one to the south the Lucky Boy prospect, as does ARDF. Robinson and Twenhofel (1953) provide a detailed map of the prospect.

Geologic setting

Geologic description

The Lady of the Lake prospect was discovered prior to 1902 (Brooks, 1902). It has been described several times in the older literature, sometimes in combination with the Lucky Boy prospect (CR174), sometimes as a distinct prospect, and sometimes as being on various claim blocks (Wright and Wright, 1906, 1908; Smith, 1914; Chapin, 1916; Buddington and Chapin, 1929; Roehm 1939 [PE 119-16]; Townsend, 1945; Twenhofel, 1953). Robinson and Twenhofel (1953) provide a detailed map and description of the prospect (under the name 'Lucky Boy North deposit'). The deposit consists of three breccia veins in black, calcareous argillite, schist, and marble. The breccias are composed of rock fragments cemented by quartz and calcite that are 'slightly mineralized' with sphalerite, galena, pyrite, and chalcopyrite. Until recently, the host rocks were considered to be part of the Wales Group of Late Proterozoic and Cambrian age (Eberlein and others, 1983; Brew, 1996). More recent mapping, however, indicates that they are previously unrecognized Silurian and Ordovician metamorphic rocks that are less deformed than those of the Wales Group (S.M. Karl, oral communication, 2003).
The lowest vein at the Lady of the Lake prospect strikes N10W and dips 70W; it is exposed for about 160 feet along the shore of Dora Lake and it about 18 inches thick. A sample across it contained 3.80 percent zinc and 0.36 percent lead. Two veins are at an elevation of about 330 feet. One of them is 7 feet thick and is exposed for about 150 feet; it strikes N35W and dips 70SW. The other is exposed for about 85 feet and is about 5 feet thick in a 65-foot adit that cuts it in the subsurface; it strikes north and dips 80W. A select sample from the dump of one of the upper veins contained 5.23 percent zinc, 2.05 percent lead, and minor silver and gold. Maas and others (1991) collected a representative 15-foot sample across one of the quartz- and calcite-cemented breccias. It contained 2.065 parts per million (ppm) gold, 4,316 ppm lead, and 1.35 percent zinc. Selected samples contained up to 0.331 ounce of gold per ton, 12.8 ppm silver, 0.97 percent lead, and 2.44 percent zinc.
The workings consist of several trenches and a 65-foot adit on the upper workings. There is no record of production. Houston Oil and Minerals Corporation sampled and possibly drilled the Lady of the Lake prospect in the late 1970s and 1980s, during their exploration of other deposits in the area. Robinson and Twenhofel (1953) estimate that the deposit contains about 7,000 tons of material with about 0.33 percent zinc, 1 percent lead, and minor silver and gold.
Geologic map unit (-132.237663937781, 55.1572054868741)
Mineral deposit model Polymetallic mineralized breccia along a shear zone.
Age of mineralization Only that it is younger than the Silurian or Ordovician host rocks.

Production and reserves

Workings or exploration The workings consist of several trenches and a 65-foot adit on the upper veins. Houston Oil and Minerals Corporation sampled and possibly drilled the Lady of the Lake prospect in the late 1970s and 1980s, during their exploration of other deposits in the area.
Indication of production None
Reserve estimates Robinson and Twenhofel (1953) estimated that the deposit contains about 7,000 tons of material with about 0.33 percent zinc, 1 percent lead, and minor silver and gold.
Production notes There is no record of production.

References

References

Hedderly-Smith, D.A., 1991, Report of the 1990 field season-Sealaska Mineral Reconnaissance Project: Sealaska Corporation: Sealaska Corporation, 2 vols., 180 p., 13 plates. (Unpublished report held by the Sealaska Corporation, Juneau, Alaska.)
Hedderly-Smith, D.A., 1992, Report of the 1991 field season - Sealaska Mineral Reconnaissance Project: Sealaska Corporation, 2 vols., 225 p. 23 plates. (Unpublished report held by the Sealaska Corporation, Juneau, Alaska.)
Hedderly-Smith, D.A., 1993, Report of the 1992 field season-Sealaska minerals reconnaissance project: Sealaska Corporation, 60 p. (Unpublished report held by the Sealaska Corporation, Juneau, Alaska.)
Hedderly-Smith, D.A., 1999, Inventory of metallic mineral prospects, showings and anomalies on Sealaska lands, 1988 through 1998: Sealaska Corporation, Juneau, Alaska, 217 p. (internal report held by Sealaska Corporation, Juneau, Alaska).
Roppel, Patricia, 1991, Fortunes from the earth: Manhattan, Kansas, Sunflower University Press, 139 p.
Townsend, Harry, 1945, Preliminary report, Lake Bay copper prospect, Prince of Wales Island: Anaconda Copper Mining Company, 5 p. (Unpublished report held as file 6357, Anaconda Collection, American Heritage Center, University of Wyoming, Laramie.)
Reporters D.J. Grybeck (Applied Geology)
Last report date 5/1/2004