Kokomo District

The Kokomo District is a zinc, silver, gold, and lead mine located in Summit county, Colorado.

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

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Site Name

Primary: Kokomo District
Secondary: Tenmile District (or Tenmile Area)
Secondary: Robinson
Secondary: McNulty

Commodity

Primary: Zinc
Primary: Silver
Primary: Gold
Primary: Lead
Secondary: Molybdenum
Secondary: Copper

Location

State: Colorado
County: Summit
District: Kokomo District

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: District
Operation Category: Past Producer
Deposit Type: polymetallic vein and replacement
Operation Type: Surface-Underground
Years of Production:
Organization:
Significant: Y

Physiography

Not available

Mineral Deposit Model

Model Name: Polymetallic replacement

Orebody

Not available

Structure

Type: L
Description: Kokomo syncline, many small high-angle faults

Alterations

Alteration Type: L
Alteration Text: widespread silicification (jasperoid)

Rocks

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

Name: Clastic Sedimentary Rock
Role: Associated
Age Type: Associated Rock
Age Young: Permian

Name: Mixed Clastic/Carbonate Rock
Role: Associated
Age Type: Associated Rock
Age Young: Pennsylvanian

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

Name: Granitoid
Role: Associated
Age Type: Associated Rock
Age Young: Pennsylvanian

Name: Metasedimentary Rock
Role: Associated
Age Type: Associated Rock
Age Young: Proterozoic

Analytical Data

Not available

Materials

Ore: Anglesite
Ore: Galena
Ore: Cerussite
Ore: Gold
Ore: Covellite
Ore: Marcasite
Ore: Malachite
Ore: Pyrite
Ore: Smithsonite
Ore: Pyrrhotite
Ore: Silver
Ore: Sphalerite
Ore: Chalcopyrite
Gangue: Limonite
Gangue: Wad

Comments

Comment (Commodity): On the basis of recorded production (1905-1965), and current (Jan. 2006) metal prices, zinc is the dominant metal, but values of silver, lead, and gold are also important. Trace amounts of molybdenite, the dominant ore mineral at the giant Climax deposit just to the south of the district, occur in high-temperature deposits.

Comment (Development): In 1895 the Wilfley concentrating table was developed and used in the Wilfley mill here to successfully separate mixed sulfide ores of lead and zinc.

Comment (Orebody): Major ore and gangue minerals in unoxidized replacement deposits (orebody 1) and in oxidized replacement deposits (orebody 2) are listed.

Comment (Production): McNulty Gulch placers, discovered in 1860, first brought miners into the district, and produced a modest amount of gold and silver.

Comment (Production): Rich oxidized silver-lead ore was discovered in sedimentary rocks in 1878, resulting in a rush to the district and production increased greatly during the next few years, before the rich ore was mined out. Value of production before 1905 is estimated to be at least $10 million.

Comment (Production): Records for 1905 to 1965 show that production included 26,860 oz. of gold, 1,792,278 oz. silver. 501,486 lb. copper, 30,423,894 lb. lead, and 74,873,416 lb. zinc, from about 514,000 tons of ore.

Comment (Geology): Ore deposit types include placers, oxidized and unoxidized massive sulfide replacement ores (the most productive), veins, and high-temperature metasomatic deposits.

Comment (Location): The Kokomo district occupies the valley of upper Tenmile Creek and its drainage basin above (south of) Wheeler Junction nearly to its headwaters and the Lake-Summit county line. It adjoins the Climax district on the south, and the upper Blue River district on the east side of the Tenmile Range, and is sometimes included in the larger Tenmile district. Most productive deposits lie within 2 miles of Kokomo (townsite) in sec. 23, T 7 S, R 79 W.

Comment (Location): Much of the district is now covered by tailings from the Climax mine and mill.

Comment (Names): Kokomo is the preferred name for the district that includes the productive replacement deposits. Tenmile includes the drainage of Tenmile Creek above Dillon, a much broader area.

Comment (Commodity): Gangue contains carbonate minerals.

References

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

Reference (Deposit): Dempsey, S., and Fell, J. E., 1986, Mining the summit-Colorado's Ten Mile district, 1860-1960: Norman, University of Oklahoma Press.

Reference (Deposit): Koschmann, A. H., and Wells, F. G., 1946, Preliminary report on the Kokomo mining district, Colorado: Colorado Scientific Society Proceedings, v. 15, no. 2, p. 51-112.

Reference (Deposit): SHARPS, 1963: CSM MIN. IND. BULL., VOL. 6, NO. 6

Reference (Deposit): CONSV. DIV. COMP. DATE, 8,65

Reference (Deposit): BERGENDAHL, M.H., AND KOSCHMANN, A.H., 1971, ORE DEPOSITS OF THE KOKOMO-TENMILE DISTRICT, COLORADO: U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 652, 53 P.

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

Reference (Deposit): Mach, C. J., 1992, Geology and mineral deposits of the Kokomo district, Colorado: Fort Collins, CO, Colorado State University, M.S. thesis, 154 p.

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