Marietta

Mine, Inactive

Alternative names

Pecos
Solo Pecos

Commodities and mineralogy

Main commodities Ag; Au
Other commodities Cu; Pb; Zn
Ore minerals electrum; gold; galena
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale BC
Quadrangle map, 1:63,360-scale A-1
Latitude 56.076
Longitude -130.258
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Marietta mine is in Section 9 at an elevation of about 4600 feet, near the lower edge of an icefield overlooking Chickamin Glacier, and about 1.6 mile north of Texas Lake (Berg and others, 1977, p. 76; Elliott and Koch, 1981, p. 11, loc. 26).

Geologic setting

Geologic description

The country rocks in the area of the Marietta mine are pelitic metasedimentary strata of the Jurassic or older Mesozoic Hazelton Group. The Hazelton is underlain and locally intruded by the Triassic Texas Creek Granodiorite, and both the Hazelton and Texas Creek rocks are intruded by the Eocene Hyder Quartz Monzonite (Berg and others, 1977, p. 15-18, 22-23; Smith, 1977; Koch, 1996).
There is no published geologic description of this deposit, which is covered by ice. The discovery around 1925 of electrum-bearing float nearby led to tunneling beneath the ice that resulted in the discovery in 1937 of a vein under the glacier (Berg and others, 1977, p. 76-77; Elliott and Koch, 1981), followed by unconfirmed reports of production of 300-400 oz of gold and electrum. A search by the U.S. Bureau of Mines in 1972-73 (Berg and others, 1977, p. 76-77) failed to find bedrock workings due to snow and ice cover. Analyses by the Bureau of Mines of sparse galena-, pyrrhotite-, and chalcopyrite-bearing quartz-calcite veinlets in graywacke and argillite near the reported mine site showed small amounts of Cu, Pb, Zn, and Ag, but virtually no gold.
Lead-isotope studies of galena from the Pecos and Solo Pecos claims in the area of the Marietta mine (Maas and others, 1995, p. 229-248) indicate that the deposits on those claims are Eocene in age, contemporaneous with emplacement of the Hyder Quartz Monzonite.
Geologic map unit (-130.259705583828, 56.0756895539249)
Mineral deposit model Polymetallic veins (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Lead-isotope studies of galena from the Pecos and Solo Pecos claims in the area of the Marietta mine (Maas and others, 1995, p. 229-248) indicate that the deposits on those claims are Eocene in age, contemporaneous with emplacement of the Hyder Quartz Monzonite.

Production and reserves

Workings or exploration
Almost 6000 feet of ice tunnels were driven to find the source of gold-and electrum-bearing float found on the mountainside below the mine.
Analyses in 1972-73 by the U.S. Bureau of Mines of sparse galena-, pyrrhotite-, and chalcopyrite-bearing quartz-calcite veinlets in graywacke and argillite near the reported mine site showed small amounts of Cu, Pb, Zn, and Ag, but virtually no gold.
Operators of the nearby Pecos and Solo Pecos claims (Maas and others, 1995, p. 238, 241, 243) explored those deposits by mapping, sampling, ground geophysical work, and limited diamond drilling, but the ground was abandoned at the time of the U.S. Bureau of Mines investigation in 1973 (Berg and others, 1977, p. 76-77).
Indication of production Yes; small
Production notes Unconfirmed report of production of 300-400 oz of gold and electrum in 1937.

Additional comments

Six claims staked in 1925. Original claims lapsed in 1950 and ground was restaked several times since then. In 1973, the nearby Pecos and Solo Pecos claims were abandoned after limited exploration work.
Some reports link the Marietta and Silver King (BC028) claims, but the latter are at a lower elevation and possibly farther south (Berg and others, 1977, p. 39).
Site is in Misty Fiords National Monument.

References