Lucky Boy

Mine, Undetermined

Alternative names

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 55.15393
Longitude -132.24225
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Lucky Boy prospect is about 0.2 mile south of the south end of Dora Lake and about 0.4 mile northwest of the center of section 36, T. 77 S., R. 87 E. Several authors combine their descriptions of this prospect with the Lady of the Lake prospect (CR173), about 0.4 mile to the northeast. 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 Lady of the Lake prospect 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 Lucky Boy prospect and the one to the north the Lady of the Lake prospect, as does ARDF. Robinson and Twenhofel (1953) and Maas and others (1995) provide maps of the workings at the Lucky Boy prospect.

Geologic setting

Geologic description

It is unclear when the Lucky Boy prospect as defined in this record was named, because in its early history it was often not distinguished from the nearby and similar Lady of the Lake prospect (CR173), which was discovered prior to 1902 (Brooks, 1902). It was known as the Lucky Boy prospect by 1933 or 1934 (Roehm, 1939 [PE 119-16]; Townsend, 1945; Robinson and Twenhofel, 1953). Before then, the deposit had been staked as part of the Complex claim group and still earlier it was described by Wright and Wright (1908) as on the Oregon and Idaho claims. By 1939, the workings included two adits, about 180 feet of crosscut, 120 feet of drift, a raise, and two small stopes (Maas and others, 1991, 1995). A small mill was built on the property in about 1916 (Roppel, 1991). There was at least one test shipment in about 1915 that was carried by aerial tram south to Miller Lake (called Mineral Lake in early reports), but there is no record that the mill actually produced concentrates. In the late 1970s and early 1980s, Houston Oil and Minerals Corporation completed several diamond drill holes on the property.
The rocks in the vicinity of the deposit consist of black, calcareous argillite, greenschist, and marble along a regional fault that strikes south from Dora Lake; the fault marks the contact between what Eberlein and others (1983) called the Wales Group of Late Proterozoic and Cambrian age and the Descon Formation of Silurian and Ordovician age (Eberlein and others, 1983). 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 deposit at the Lucky Boy prospect is along a shear zone up to 8 feet wide that strikes N22E and dips 35E (Roehm, 1939 [PE 119-6]; Twenhofel, 1943; Townsend, 1945; Robinson and Twenhofel, 1953; Maas and others, 1991, 1995; Hedderly-Smith, 1999 [Inventory]). The shear zone is oblique to the foliation of the host rocks and is filled with rock fragments (breccia) cemented by quartz and calcite. The breccia contains several percent of sphalerite, galena, pyrite, and chalcopyrite. The shear zone can be traced for about 380 feet in surface pits and is exposed in the underground workings where it notably leaner than at the surface. The mineralization has been sampled many times with varying results, depending on the selection of the samples (Roehm, 1939 [PE 1996-6]; Townsend, 1945; Robinson and Twenhofel, 1953). Mass and others (1991, 1995) collected samples in the trenches and underground. Their higher grade samples contained 84 to 6,017 parts per billion gold, up to 40.8 parts per million (ppm) silver, 0.47 to 0.77 percent lead, 0.32 to 1.18 percent copper, and 8.92 to 20.35 percent zinc. Robinson and Twenhofel (1953) estimated that the deposit contains about 1,500 tons of material with an average grade of about 3 percent zinc.
The deposit as now exposed is an epigenetic mineralized breccia along a shear zone. However, Houston Oil and Minerals Corporation, who drilled the prospect in the late 1970s and early 1980s, did so to test the theory that the mineralization in the shear zone is remobilized from an as yet undiscovered, stratiform volcanogenic massive-sulfide deposit (Douglas Oliver, oral communication, 1983).
Geologic map unit (-132.243913628168, 55.1535756867077)
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 It is unclear when the Lucky Boy prospect as defined in this record was named, because in its early history it was often not distinguished from the nearby and similar Lady of the Lake prospect (CR173), which was discovered prior to 1902 (Brooks, 1902). It was known as the Lucky Boy prospect by 1933 or 1934 (Roehm, 1939 [PE 119-16]; Townsend, 1945; Robinson and Twenhofel, 1953). Before then, the deposit had been staked as part of the Complex claim group and still earlier it was described by Wright and Wright (1908) as on the Oregon and Idaho claims. By 1939, the workings included two adits, about 180 feet of crosscut, 120 feet of drift, a raise, and two small stopes (Maas and others, 1991, 1995). A small mill was built on the property in about 1916 (Roppel, 1991). There was at least one test shipment in about 1915 that was carried by aerial tram south to Miller Lake (called Mineral Lake in early reports), but there is no record that the mill actually produced concentrates. In the late 1970s and early 1980s, Houston Oil and Minerals Corporation completed several diamond drill holes on the property.
Indication of production Yes
Reserve estimates Twenhofel (1953) estimated that the deposit contains about 1,500 tons of material with about 3 percent zinc.
Production notes There was at least one test shipment in about 1915 that was carried south by an aerial tram to Miller (Mineral) Lake, but there is no record that the small mill actually produced concentrates.

References

MRDS Number A010156

References

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