Leadville District

Site Name

Primary: Leadville District
Secondary: California (California Gulch)
Secondary: Evans
Secondary: Iowa
Secondary: Empire
Secondary: Breece Hill
Secondary: Carbonate Hill
Secondary: Downtown
Secondary: Fryer Hill
Secondary: Iron Hill
Secondary: Rock Hill
Secondary: Sacrament
Secondary: Greenback
Secondary: Black Cloud
Secondary: Yak Tunnel
Secondary: Newton and Flagstaff claims
Secondary: Matchless
Secondary: Morning Star
Secondary: Iron Silver
Secondary: Catalpa
Secondary: Chrysolite
Secondary: Little Pittsburgh
Secondary: AY (also A. Y. 1, A. Y. 2, A. Y. 3) and Minnie

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Commodity

Primary: Lead
Primary: Gold
Primary: Zinc
Primary: Silver
Secondary: Manganese
Secondary: Copper
Secondary: Bismuth
Secondary: Sulfur, Sulfuric Acid
Secondary: Iron
Tertiary: Cadmium
Tertiary: Tungsten
Tertiary: Vanadium

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Location

State: Colorado
County: Lake
District: Leadville District

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Land Status

Not available

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Holdings

Not available

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Workings

Not available

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Ownership

Not available

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Production

Year: 1999
Time Period: 1860-1999
Mined: 2600000.000 mt
Material type: Iron-silver and iron-manganese-silver ore. From comment by Richard Beach, reporter.
Year: 1999
Time Period: 1860-1999
Mined: 29000000.000 mt
Year: 1999
Time Period: 1860-1999
Mined: 900000.000 mt
Material type: Iron-silver and iron-manganese-silver ore. From comment by Richard Beach, reporter.

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Deposit

Record Type: District
Operation Category: Past Producer
Deposit Type: polymetallic vein, massive sulfide manto
Operation Type: Surface-Underground
Year First Production: 1860
Year Last Production: 1999
Years of Production:
Organization:
Significant: Y

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Physiography

Not available

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Mineral Deposit Model

Model Name: Polymetallic replacement
Model Name: Placer Au
Model Name: Mississippi Valley, S.E. Missouri Pb-Zn

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Orebody

Not available

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Structure

Type: L
Description: numerous faults of several periods

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Alterations

Alteration Type: L
Alteration Text: silicification, sericitization

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Rocks

Name: Granite
Role: Associated
Age Type: Associated Rock
Age Young: Tertiary

Name: Porphyry
Role: Host
Age Type: Host Rock
Age Young: Pennsylvanian

Name: Arkose
Role: Host
Age Type: Host Rock
Age Young: Pennsylvanian

Name: Black Shale
Role: Host
Age Type: Host Rock
Age Young: Mississippian

Name: Dolomite
Role: Host
Age Type: Host Rock
Age Young: Late Devonian

Name: Sandstone
Role: Host
Age Type: Host Rock
Age Young: Devonian

Name: Dolomite
Role: Host
Age Type: Host Rock
Age Young: Devonian

Name: Sandstone
Role: Host
Age Type: Host Rock
Age Young: Ordovician

Name: Dolomite
Role: Host
Age Type: Host Rock
Age Young: Cambrian

Name: Shale
Role: Host
Age Type: Host Rock
Age Young: Cambrian

Name: Orthoquartzite
Role: Host
Age Type: Host Rock
Age Young: Proterozoic

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Analytical Data

Not available

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Materials

Ore: Hematite
Ore: Pyrite
Ore: Cerussite
Ore: Gold
Ore: Cerargyrite
Ore: Galena
Ore: Magnetite
Ore: Argentite
Ore: Chalcopyrite
Ore: Chalcocite
Ore: Sphalerite
Ore: Wad
Ore: Smithsonite
Ore: Silver
Ore: Manganese Ox-Hydrous
Ore: Limonite
Ore: Hemimorphite
Gangue: Siderite
Gangue: Serpentine
Gangue: Quartz

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Comments

Comment (Commodity): Gangue contains manganoan siderite (manganosiderite).

Comment (Reserve-Resource): Low-grade manganese resources may total 2,000,000 tons of oxidized ore, containing 10% to 35 % Mn, plus 2,000,000 tons of primary (manganosiderite) ore, containing 14 to 20 % Mn. (Hedges, J. H., 1940)

Comment (Orebody): Major minerals in each of four types of orebodies are listed: (1) hypogene oxide-silicate ore, (2) hypogene sulfide veins and stockworks, (3) blanket or manto replacement ore, and (4) oxidized or supergene ore.

Comment (Production): After 140 years of nearly continuous mining activity, the Leadville district ranks among the most productive areas for base and precious metals in the U.S. First, gold placer deposits, then lode gold deposits were worked, from 1860 to 1875; oxidized silver-lead ores were dominant from 1876 to 1902; then oxidized zinc ores were worked from 1902 to 1923; finally, mixed sulfide base- and precious-metal ores were mined from 1924 almost continuously until 1999.

Comment (Production): An estimate of total metal production, based on published reports and the reporter's estimate of recent production, includes 3,250,000 oz of gold, 270,000,000 oz of silver, 53,000 tons of copper, 1,200,000 tons of lead, and 1,235,000 tons of zinc. Nearly 29 million tons of ore were mined. Almost 1,000,000 tons of manganiferous iron ore and 2,900,000 tons of iron-silver and iron-manganese-silver ore, plus an unknown quantity of pyrite, was produced.

Comment (Commodity): At today's metal prices (2006), silver, zinc, gold, and lead are the main products of the district; copper is a byproduct. Manganiferous iron ore was used in steelmaking; iron-silver and iron-manganese-silver ores were produced for smelter flux. Bismuth and cadmium were recovered as byproducts of smelting. Pyrite was used to make sulfuric acid. Tungsten minerals (in one orebody) and vanadium minerals are reported but have not been recovered.

Comment (Production): For the 1860-1999 cumulative production listed in the previous comment, assuming the amounts are metric tons, at 2010 prices the commodity importance order and dollar value in millions is: Ag $4.9 Au $3.7 Zn $3.0 Pb $2.6 Cu $0.4 For the 1860-1963 cumulative production, Tweto, 1968, lists the relative economic importance as follows: 37% Silver 22% Zinc 21% Lead 13% Gold 3% Copper 4% Other including Bi and Mg

Comment (Geology): Granitic and metamorphic basement rocks are overlain by 500 feet of east-dipping marine Paleozoic sedimentary rocks, cut by numerous faults, and intruded by many Tertiary igneous rocks. Five types of orebodies are: (1) hypogene oxide-silicate ore, (2) hypogene sulfide veins and stockworks, (3) blanket or manto replacement ore, (4) oxidized or supergene ore, and (5) placer deposits.

Comment (Location): The district extends from Leadville east to the crest of the Mosquito Range and from Canterbury Hill and Prospect Mountain on the north to Empire Gulch on the south. It includes about 30 square miles, mostly in T 9 S, R 79 and 80 W. The most intensely mineralized area lies immediately east of Leadville and covers about 8 square miles.

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References

Reference (Deposit): Sunshine Mining Co. Colorado exploration files, unpublished data, Colorado Geological Survey.

Reference (Deposit): Tweto, O., 1968, Leadville district, Colorado, in Ridge, J. D., editor, Ore deposits of the United States, 1933-1967 (Graton-Sales volume): New York, American Institute of Mining Engineers, p. 681-705.

Reference (Identification): Smith, D.A., 1977, Colorado Mining--A photographic history: Albuquerque, Univ. of New Mexico Press, 176 p.
Pages: p. 125.

Reference (Deposit): Leach, D., Sangster, D., Kelley, K., Large, R.R., Garven, G., Allen, C., Gutzmer, J., and Walters, S., 2005, Sediment-hosted lead-zinc deposits: A global perspective. Economic Geology, 100th Aniversary Volume. pp. 561-607. Also Appendices A, B, C, D, E, and Supplement
Pages: a

Reference (Deposit): Behre, C. H., Jr., 1953, Geology and ore deposits of the west slopeof the Mosquito Range (Colorado): U.S. Geological Survey Professional Paper 235, 176 p.
Pages: pl.1.

Reference (Deposit): Emmons, S.F., Irving, J.D., and Loughlin, G.F., 1927, Geology and ore deposits of the Leadville mining district, Colorado: U.S. Geological Survey Professional Paper 148, 368 p.

Reference (Deposit): Johansing, R.J., and Thompson, T.B., 1990, Geology and origin of Sherman-type deposits, central Colorado: Economic Geology Monograph 7.
Pages: 367-394

Reference (Deposit): Thompson, T. B., and Arehart, G. B., 1990, Geology and the origin of ore deposits in the Leadville district, Colorado: Part I. Geologic studies of orebodies and wall rocks: Economic Geology Monograph 7, p. 130-155.

Reference (Deposit): Harrer, C.M., and Tesch, W.J., Jr., 1959, Reconnaissance of iron occurrences in Colorado, U.S. Bureau of Mines Information circular 7918, 82 p.

Reference (Names): Dunn, L.G, 2003, Colorado mining districts: A reference: Golden, Colo., Colorado School of Mines Library, 364 p.

Reference (Reserve-Resource): Hedges, J. H., 1940, Mineral industries survey of the United States, Colorado, Lake County, Possibilities of manganese production at Leadville, Colo.: U.S. Bureau of Mines Information Circular 7125, 23 p.

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