Baltic Star

Prospect, Undetermined

Alternative names

Queen

Commodities and mineralogy

Main commodities Au
Other commodities Pb; Zn
Ore minerals galena; gold; pyrite; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale KC
Quadrangle map, 1:63,360-scale B-4
Latitude 55.381
Longitude -131.192
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Baltic Star and Queen claims extend from the shore of Thorne Arm east-northeastward to an elevation of approximately 200 feet, about 0.3 mile west-southwest of the head of Star Lake The map site is in section 7, T. 75 S., R. 94 E., of the Copper River Meridian, about at the junction of the two claims, and is accurate within a few hundred feet. The site corresponds to loc. 88 in Elliott and others (1978), who, following an error in Wright and Wright (1908), erroneously call it 'Baltic/Queen.'

Geologic setting

Geologic description

The country rocks in this part of Revillagigedo Island are marine, interbedded, andesitic and basaltic metavolcanic rocks and subordinate pelitic metasedimentary rocks that are intruded by stocks, sills, and dikes of Cretaceous feldspar-porphyritic granodiorite (Berg and others, 1988). The strata and some of the granodiorite were regionally metamorphosed to greenschist grade in Late Cretaceous time. These regionally metamorphosed rocks subsequently were locally remetamorphosed to hornblende hornfels near the contacts of Cretaceous granodiorite plutons that were emplaced after the regional metamorphism. The premetamorphic age of the strata is uncertain. Berg and others (1988) assign them a Mesozoic or (late) Paleozoic age. Berg (1982) and Crawford and others (2000) assign them to the Gravina belt, of Late Jurassic or Cretaceous age, or to the Taku terrane, of late Paleozoic to Late Triassic age. The metamorphic and intrusive rocks locally are overlain by basalt and andesite lava flows of Quaternary or Tertiary age.
The Baltic Star and Queen claims are on a quartz fissure vein that strikes generally eastward and dips steeply to vertically, across the foliation of the enclosing schist, which strikes N20W and dips 70NE (Wright and Wright, 1908, p. 148). The vein is 1-6 feet thick and contains small amounts of pyrite, sphalerite, and [probably] galena, along with low values in gold. The deposit was explored in the early 1900s by opencuts, two short prospect tunnels, and an inclined shaft 40 feet deep (Wright and Wright, 1908, p. 148). Maas and others (1995, p. 215) note that the quartz in the veins in this area is not recrystallized; the veins thus are probably younger than most or all of the Late Cretaceous regional metamorphism.
Geologic map unit (-131.193694214298, 55.3806597526802)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Maas and others (1995, p. 215) note that the quartz in the veins in this area is not recrystallized; the veins thus are probably younger than most or all of the Late Cretaceous regional metamorphism.

Production and reserves

Workings or exploration The deposit was explored in the early 1900s by opencuts, two short prospect tunnels, and an inclined shaft 40 feet deep (Wright and Wright, 1908, p. 148).
Indication of production None

Additional comments

The Baltic Star prospect was erroneously called 'Baltic' by Wright and Wright (1908, p. 148) and by Elliott and others (1978, loc. 88).

References