Democrat Hill deposit

The Democrat Hill deposit is a gold, aluminum, potassium, and silver mine located in Custer county, Colorado at an elevation of 9,101 feet.

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: Democrat Hill deposit

Commodity

Primary: Gold
Primary: Aluminum
Primary: Potassium
Primary: Silver
Secondary: Lead
Secondary: Zinc

Location

State: Colorado
County: Custer
District: Rosita Hills District

Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

Holdings

Not available

Workings

Type: Surface/Underground

Ownership

Not available

Production

Year: 1886
Time Period: 1886
Mined: 180.000 mt
Material type: silver ore

Deposit

Record Type: Deposit
Operation Category: Past Producer
Operation Type: Underground
Discovery Year: 1890
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: L

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains
Physiographic Detail: Democrat Hill, Rosita Hills

Mineral Deposit Model

Model Name: Epithermal quartz-alunite Au

Orebody

Form: LARGE CHIMNEY (VOLCANIC CONDUIT)

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Alunitization, Silicification, Kaolinization. Alteration Of Rhyolite To Alunite By Solfataric Action

Rocks

Name: Rhyolite
Role: Associated
Age Type: Host Rock Unit
Age Young: Pliocene

Analytical Data

Analytical Data: 2 ANALYSES ARE 16.6 % AND 32.3 % ALUNITe

Materials

Ore: Galena
Ore: Sphalerite
Ore: Alunite
Ore: Diaspore
Ore: Kaolinite
Ore: Pyrite
Gangue: Quartz

Comments

Comment (Reserve-Resource): Estimated 800,000 tons alunite resource @ 16.6% alunite. (Thoenen, 1941)

Comment (Reserve-Resource): A 1981 report suggested that low-grade, bulk-tonnage silver deposits may occur in this area. (Sunshine files)

Comment (Reserve-Resource): GREATER PART OF RESERVE IS INFERRED

Comment (Reserve-Resource): ALUNITIZED BODY IS LOW-GRADE

Comment (Workings): OLD BEN EATON ( 500 FT ) AND DEMOCRAT ( 435 FT ) ADITS DRIVEN INTO S BASE OF DEMOCRAT HILL IN 1870'S FOR SILVER AND OTHER METALS, NOT ALUNITE. ALSO SEVERAL PROSPECT HOLES AND DRIFTS.

Comment (Commodity): PROJECT 9350 - 01393 ALUNITE RESOURCES

Comment (Development): ECON.COM: DEPOSIT IS LESS THAN 1 MI. FROM A ROAD AND THERE IS LITTLE OVERBURDEN. ALUNITE IS CLOSELY LOCKED WITH QUARTZ

Comment (Location): S CENTRAL PART OF ROSITA HILLS. S END OF DEMOCRAT RIDGE, ABOUT 1-1/2 MILE WNW OF ROSITA, IN THE E/2 SEC 30, T 22 S, R 71 W.

References

Reference (Deposit): 1883 GEOLMAP W. CROSS: PUB. REPTS.

Reference (Deposit): 1942 RECON L. S. GARDNER: UNPUB. REPT.

Reference (Deposit): 1878 DIREXPL UNKNOWN: PROSPECTING WORKS

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

Reference (Analytical Data): THOENEN, J. R., 1941 , ALUNITE RESOURCES OF THE UNITED STATES: USBM REPT. INV. 3561 , P. 13.
Pages: p. 13.

Reference (Reserve-Resource): THOENEN, J. R., 1941 , ALUNITE RESOURCES OF THE UNITED STATES: USBM REPT. INV. 3561 , P. 13 - 14.
Pages: p. 13-14.

Reference (Deposit): THOENEN, J. R., 1941 , ALUNITE RESOURCES OF THE UNITED STATES: USBM REPT. INV. 3561 , P. 13 - 14.
Pages: p. 13-14.

Reference (Geology): SHARP, W.N., 1978, GEOLOGIC MAP OF THE SILVER CLIFF AND ROSITA VOLCANIC CENTERS, CUSTER COUNTY, COLORADO: USGS MAP I-1081, 1:24,000.

Reference (Deposit): GARDNER, L. S., 1943 , UNPUB. REPT. IN USGS FILE

Reference (Deposit): CROSS, C. W., 1912 , ALUNITE DEPOSITS OF ROSITA HILLS, COLORADO, USGS BULL. 511 , P. 38 - 41 .

Reference (Deposit): CROSS, C. W., 1891 , ON ALUNITE AND DIASPORE FROM THE ROSITA HILLS, COLORADO: AM. JOUR. SCI., 3RD SER., V. 41 , NO. 246 , P. 466 - 475 .

Reference (Deposit): CROSS, C. W., 1896 , GEOLOGY OF SILVER CLIFF AND THE ROSITA HILLS, COLORADO: USGS 17TH ANN. REPT., PT. 2 , P. 314 - 315 , 377 - 378 .

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