Valpariso

Mine, Active?

Commodities and mineralogy

Main commodities Ag; Au
Other commodities Cu; Pb; Sb; Zn
Ore minerals chalcopyrite; galena; gold; pyrite; sphalerite; tetrahedrite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale CR
Quadrangle map, 1:63,360-scale A-1
Latitude 55.1456
Longitude -132.0793
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Valpariso Mine is near the north shore of Paul Lake, about 0.4 mile southwest of Dolomi Mountain. It is not at the mine symbol that is misplaced about a half mile to the west on the USGS 1:63,360-scale topographic map. Instead, it is about 0.3 mile south-southeast of the center of section 36, T. 77 S., R. 88 E. The Paul or Jessie prospect (CR200) to the east is an extension of the vein at the Valpariso Mine and descriptions of that prospect sometimes have been combined with that of the mine; they were often managed by the same company. The underground workings of the mine are shown on figure 30 of Maas and others (1995).

Geologic setting

Geologic description

The Valpariso Mine was the most productive mine in the Dolomi area and has been described in many publications (for example: Brooks, 1902; Wright and Wright 1905, 1906, 1908; Smith, 1914; Smith, 1934a, Smith, 1934b, ; Galloway, 1952; Dyer, 1952, 1956; Herreid, 1967; Maas and others, 1991, 1995). By 1902, the mine had been developed by two shafts and three ore shipments of 31, 50, and 60 tons has been made to a smelter in California. Development and production took place intermittently from 1898 to 1920, and the deposit was mined by a lessor in 1927 and again in 1932. The surface mine plant and mill were extensively rebuilt in 1935 and again from 1946 to 1948 but no ore was produced before funds ran out. Roppel (2005) presents a detailed historical survey of the mine from its earliest days and the many legal, personality , water, and power problems, and management changes that repeatedly stymied mining.
The workings consisted of two (four?) shafts, the deepest of which was 400 feet deep, and extensive workings on at least three levels. Smith (1934a, 1934b) and Dyer (1952, 1956) reported that the mine produced about 5,000 ounces of gold to 1933. U.S. Bureau of Mines records document the production of about 730 ounces of gold and 521 ounces of silver from 1914 to 1933 (Maas and others, 1991, 1995). Galloway (1952) estimated that the total production from the mine was about $100,000 (plus some production, probably small, from leasers), mostly from 1901 to 1908. In 1983 and 1984, Houston Oil and Mineral Exploration Corporation drilled 21 holes at the mine and at the Paul Lake (CR200), Amazon (CR209), and Boston (CR207) properties (Oliver and Adams, 1984).
The host rocks at the Valpariso Mine are marble and schist of the Wales Group of Late Proterozoic and Cambrian age (Eberlein and others, 1983). The deposit consists of a vein up to 14 feet thick of quartz, quartz breccia, and quartz-marble breccia cemented by calcite; the vein is locally faulted and the marble is extensively silicified. The vein is conformable to the bedding of a thick marble layer. In an adit about 600 feet west of the mill, the marble is in contact with chlorite schist and quartzite or jasperoid. The vein strikes about N55W and dips 30-70N; it can be traced for as much as 6,000 feet to the east, to and beyond the Paul or Jessie prospect (CR200). The vein typically contains about 1 percent ore minerals, including free gold, tetrahedrite, pyrite, chalcopyrite, galena, and sphalerite. Some of the ore was very rich; some ore mined in early 1900s ran $200-$250 a ton in gold (at $20.67 an ounce) and silver (Brooks, 1902). Samples of veins and old dumps collected in 1934 ran $5.50 to $42.07 a ton in gold (at $35 per ounce) and silver (Smith, 1934). In 1934, after the last mining, Smith estimated that the deposit contained 22,500 tons of probable ore in place with an average grade of 0.28 ounce of gold per ton and minor silver. Maas and others (1991) collected 34 samples in the underground workings. Their gold values varied greatly; the best was 4.660 ounces of gold per ton across 1.2 feet, but most samples contained much less. The highest silver value was 6.18 ounces of silver per ton.
Geologic map unit (-132.080967202348, 55.145244405503)
Mineral deposit model Low-sulfide, brecciated gold-quartz vein (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization The vein is younger than the Late Proterozoic or Cambrian host rocks.
Alteration of deposit The vein is locally faulted and the marble is extensively silicified.

Production and reserves

Workings or exploration The workings consisted of two (four?) shafts, the deepest of which was 400 feet deep, and there were extensive workings on at least three levels. In 1983 and 1984, Houston Oil and Mineral Exploration Corporation drilled 21 holes at the mine and at the Paul Lake (CR200), Amazon (CR209), and Boston (CR207) properties (Oliver and Adams, 1984).
Indication of production Yes; small
Reserve estimates In 1934, after the last mining, Smith estimated that the deposit contained 22,500 tons of probable ore in place with an average grade of 0.28 ounce of gold per ton and minor silver.
Production notes Smith (1934) and Dyer (1952, 1956) reported that the mine produced about 5,000 ounces of gold to 1933. U.S. Bureau of Mines records document the production of about 730 ounces of gold and 521 ounces of silver from 1914 to 1933 (Maas and others, 1991, 1995). Galloway (1952) estimated that the total production from the mine was about $100,000 (plus some production, probably small, from leasers), mostly from 1901 to 1908.

Additional comments

Roppel (2005) includes an extensive bibliography of the history of the mine.

References

MRDS Number A010162

References

Dyer, H.O., 1952, Report on the Dolomi Mine, Prince of Wales Island, Alaska, 8 p. (Unpublished report held by the Alaska Division of Geological and Geophysical Surveys, Fairbanks.)
Dyer, H.O., 1956, Report on the Dolomi Mine, Prince of Wales Island, Alaska, 20 p. (Unpublished report held by the Alaska Division of Geological and Geophysical Surveys, Fairbanks.)
Oliver, D.H., and Adams, J.B., 1984, Dolomi gold project, progress report: Houston Oil and Minerals Exploration Company, 41 p. (Unpublished report held by the Bureau of Land Management, Mineral Information Center, Juneau, Alaska.)
Roppel, Patricia, 2005, Striking it rich! Gold mining in southern Southeastern Alaska: Greenwich, Connecticut, Coachlamp Productions, 286 p.
Smith, S.S., 1917, The mining industry in the Territory of Alaska during the calendar year 1915: U.S. Bureau of Mines Bulletin 142, 65 p.
Smith, S.S., 1917, The mining industry in the Territory of Alaska during the calendar year 1916: U.S. Bureau of Mines Bulletin 153, 89 p.
Reporters D.J. Grybeck (Port Ludlow, WA)
Last report date 3/4/2008