Frenchie

The Frenchie is a copper, zinc, gold, and lead mine located in Alaska.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Frenchie
Secondary: BP Adit

Commodity

Primary: Copper
Primary: Zinc
Primary: Gold
Primary: Lead
Secondary: Barium-Barite

Location

State: Alaska
District: Petersburg

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Unknown
Years of Production:
Organization:
Significant:

Physiography

Not available

Mineral Deposit Model

Model Name: Massive sulfide, Sierran kuroko
Model Name: Massive sulfide, kuroko

Orebody

Not available

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Host Rock Is Rhyolite Tuff (?) Altered To Phyllite And Schist

Rocks

Name: Andesite
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene

Analytical Data

Not available

Materials

Ore: Pyrite
Ore: Sphalerite
Ore: Galena

Comments

Comment (Geology): Age = Late Triassic as part of the Duncan-Zarembo mineral belt defined by Berg and Grybeck (1980) and Berg (1981).

Comment (Geology): Geologic Description = Although first described as a gold prospect by Buddington in 1923, this prospect remained largely unrecognized as a volcanogenic massive-sulfide deposit until work by the USGS in the early 1980's relocated the prominent outcrop along the creek bank that consists mainly of thick layers of pyrite (Berg and Grybeck, 1980; Berg, 1981; Grybeck, Berg, and Karl, 1984). The pyrite zone has an aggregate thickness of about 15 feet and extends for at least 600 feet along the creek bank. One layer about 4 feet thick consists of 50-75% massive sulfides in a siliceous matrix. The sulfides are chiefly pyrite, accompanied by minor sphalerite, chalcopyrite, and galena that form lenses, bands, and knots in the massive pyrite. Grab samples of the massive pyrite layer show 0.20 to 5.50 ppm Au, up to 2% Cu, 1% Zn, 1% Pb, 20 ppm Ag, and more than 5000 ppm Ba. The massive pyrite layers are interbedded with reddish and greenish gray siliceous metavolcanic rocks. The footwall is muscovite phyllite and minor black limestone; the hanging wall is light greenish gray phyllitic to schistose rhyolite tuff(?). All are intruded by Tertiary(?) andesite dikes. Interpreted by Berg and Grybeck (1980) and Berg (1981) as a Triassic volcanogenic massive-sulfide deposit, one of several in a belt that extends along Duncan Canal to Zarembo Island. ? Regional mapping by Brew (1997 [OF 97-156-E]) and more recent mapping by Karl (oral communications, 1998) confirm that the prospect is in rocks of the Triassic Hyd Group that contain the volcanogenic massive sulfide deposits of the Duncan-Zarembo mineral belt.

Comment (Deposit): Model Name = Kuroko volcanogenic massive sulfide deposit (Singer and Cox, 1986; model 28a ), or Sierran Kuroko volcanogenic massive sulfide deposit (Bliss, 1992; model 28a1)

Comment (Exploration): Status = Active

Comment (Production): Production Notes = None

Comment (Reference): Primary Reference = Grybeck, Berg, and Karl, 1984

Comment (Workings): Workings / Exploration = Although first described in 1923, it was largely forgotten prior to 1980. Since then, the property has repeatedly been staked and drilled by industry. A block of 34 claims roughly centered on the prospect staked in 1978; these claims were active through at least 1982, and these or other claim blocks probably have been active since. The property has been drilled several times since then, most recently by Westmin Resources in 1996.

References

Reference (Deposit): Berg, H.C., 1981, Upper Triassic volcanogenic massive sulfide metallogenic province identified in southeastern Alaska, in Albert, N.R.D., and Hudson, T.L., eds., The United States Geological Survey in Alaska: accomplishments during 1979: U.S. Geological Survey Circular 823-B, p. B104-B108.

Reference (Deposit): Grybeck, D.J., Berg, H.C., and Karl, S.M., 1984, Map and description of the mineral deposits in the Petersburg and eastern Port Alexander quadrangles: U.S. Geological Survey Open-File Report 84-837, 86 p., 1 sheet, scale 1:250,000.

Reference (Deposit): Brew, D.A., 1997, Reconnaissance geologic map of the Petersburg B-3 quadrangle, southeastern Alaska: U.S. Geological Survey Open-File Report 97-156-E, 21 p., 1 sheet, scale 1:63,360.

Reference (Deposit): Buddington, A.F., 1923, Mineral deposits of the Wrangell district; U.S. Geological Survey Bulletin 739, p. 51-75.

Reference (Deposit): Berg, H. C., and Grybeck, Donald, 1980, Upper Triassic volcanogenic Zn-Pb-Ag (-Cu-Au) mineral deposits near Petersburg, Alaska: U.S. Geological Survey Open-File Report 80-527, 11 p., 1 oversize sheet.

The Top Ten Gold Producing States

These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.