Bluebird

Prospects, Undetermined

Alternative names

Westlake
Homestake
Little Annie

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Cu; Pb
Ore minerals galena; gold; hematite; pyrite; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale CR
Quadrangle map, 1:63,360-scale A-1
Latitude 55.1027
Longitude -132.16612
Nearby scientific data Find additional scientific data near this location
Location and accuracy This site represents three neighboring claims: the Bluebird, Homestake, and Little Annie. The Bluebird was explored by a 40-foot shaft, which is at an elevation of about 1,500 feet. It is about 1.0 mile southwest of the head of Cannery Cove in about the center of the SW1/4 section 16, T. 78 S., R. 88 E.

Geologic setting

Geologic description

When first described by Brooks (1902) and Wright and Wright (1908), the property consisted of three claims: the Little Annie, Homestake, and Bluebird. At the Little Annie prospect, at an elevation of about 1,200 feet, quartz stringers oriented N30E, 70 SE in granite contain sparse pyrite and low gold values. The Little Annie may be the 'Bluebird East' prospect of Maas and others (1995), where samples contained negligible gold values. The Bluebird claim, at an elevation of about 1,500 feet, was explored in the early 1900s by a 40-foot shaft and several pits. A 3- to 6-foot-thick quartz vein that contains sparse galena, sphalerite, pyrite, and free gold cuts phyllite and greenschist near a granitic intrusion. Samples reportedly contained up to $40 to $60 a ton in gold (at $20.67 per ounce). Maas and others (1992) describe a vein up to 3 feet thick on the Bluebird claim. The vein strikes about N60W and dips 45 SW; it can be traced for about 90 feet. It consists mostly of smoky quartz with sparse pyrite, hematite, and sulfides. Samples across 0.8 to 2.7 feet of the vein contained 6 to 228 parts per million (ppm) gold, up to 198 ppm lead, and 301 ppm zinc. The wallrock of the vein is silicified. Selected samples from dumps contained up to 1.901 ounces of gold per ton.
The age of the rocks in the area has been variously interpreted. Eberlein and others (1983) mapped the strata as locally metamorphosed graywacke of Silurian or Ordovician age, near a large Paleozoic or Mesozoic granitic intrusion. Gehrels (1992) and Maas and others (1995) mapped them as pre-Ordovician metamorphosed volcanic and sedimentary rocks near a Silurian or Ordovician granitic intrusion. Brew (1996) called them Late Proterozoic and Cambrian Wales Group schist, phyllite, and marble, near a Tertiary granitic intrusion of intermediate composition. Most recently, Slack and others (2002) and S.M. Karl (oral communication, 2003) mapped the strata as Silurian and Ordovician, low-grade, regionally metamorphosed sedimentary and volcanic rocks.
Geologic map unit (-132.167776382408, 55.1023477539347)
Mineral deposit model Low-sulfide gold-quartz vein (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization Uncertain; depending on the age of the host rock, may be Late Proterozoic or younger, or Tertiary or younger.
Alteration of deposit Silicification of wallrock near vein(s).

Production and reserves

Workings or exploration The Bluebird claim was explored by a 40-foot shaft and pits prior to WW I.
Indication of production None

References

MRDS Number A101172

References

Slack, J.F., Shanks, W.C. III, Karl, S.M., Ridley, W.I., and Bittenbender, P.E., 2002, Geochemical and sulfur isotope compositions of Late Proterezoic and early Paleozoic volcanogenic massive sulfide deposits, Prince of Wales Island and vicinity, southeastern Alaska (abs.): Geological Society of America, Abstracts with Programs, v. 34 (6), p. 113.
Reporters D.J. Grybeck (Applied Geology)
Last report date 5/1/2004