Gem Park District

The Gem Park District is a vermiculite, nickel, thorium, niobium (columbium), iron, and ree mine located in Fremont 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

Name: Gem Park District  

State:  Colorado

County:  Fremont

Elevation:

Commodity: Vermiculite, Nickel, Thorium, Niobium (Columbium), Iron, REE

Lat, Long: 38.26833, -105.54639

Map: View on Google Maps

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.


Satelite image of the Gem Park District

Gem Park District MRDS details

Site Name

Primary: Gem Park District


Commodity

Primary: Vermiculite
Primary: Nickel
Primary: Thorium
Primary: Niobium (Columbium)
Primary: Iron
Primary: REE
Secondary: Copper
Secondary: Phosphorus-Phosphates
Secondary: Silver
Secondary: Cobalt


Location

State: Colorado
County: Fremont
District: Gem Park 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
Operation Type: Unknown
Years of Production:
Organization:
Significant:


Physiography

Not available


Mineral Deposit Model

Not available


Orebody

Not available


Structure

Type: L
Description: alkalic igneous complex;


Alterations

Alteration Type: L
Alteration Text: fenitization


Rocks

Name: Intrusive Carbonatite
Role: Host
Age Type: Host Rock
Age Young: Cambrian

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

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


Analytical Data

Not available


Materials

Not available


Comments

Comment (Commodity): The "Mag Lode" prospect contains titanium-bearing iron ore. It is possibly titaniferous magnetite similar to that at Iron Mountain which is about seven miles northeast of the Gem Park district in the McClure Mountain igneous complex.

Comment (Geology): Cambrian mafic and ultramafic alkalic complex.

Comment (Location): On the Custer County - Fremont County border. Wet Mountains.

Comment (Location): Basically coincident with the Gem Park igneous complex.

Comment (Production): A significant tonnage of vermiculite has been produced from the Goldenite and Silverite mines (Bush, 1951). Small amounts of nickel, copper (?), and silver were produced from the Gem Mine in the 1800s.

Comment (Reserve-Resource): Reserves/resources not defined.

Comment (Commodity): Parker and Sharp (1970) believe that a significant niobium-REE-thorium deposit may lie within a carbonatite mass that they postulate lies beneath the fenitized mass at the Vermiculite Mine in this district.

Comment (Commodity): Copper and nickel occur in the area but have not been sufficiently evaluated. Copper occurs as chalcopyrite in coarse pyroxenite at the periphery of the Gem Park complex, in fenitized rock at the Vermiculite Mine, and in a few carbonatite dikes. The "Gem Mine" on the northern periphery of the district contains nickel, copper, silver, and cobalt. Minerals there include niccolite, annabergite, and native silver. It was mined in the 1800s (Cappa, 1998).

Comment (Commodity): The "Goldenite" and "Silverite" mines are part of a large, blanket-like vermiculite deposit (Bush, 1951). A large tonnage of material was produced in the past and is of a good grade.

Comment (Commodity): Armbrustmacher and others (1988) report detailed mineralogy of carbonatites from drill core.


References

Reference (Geology): Parker, R.L., and Sharp, W.N., 1970, Mafic-ultramafic igneous rocks and associated carbonatites of the Gem Park Complex, Custer and Fremont counties, Colorado: U.S. Geological Survey Professional Paper 649, 24 p.

Reference (Deposit): Bush, A.L., 1951, Sources of lightweight aggregate in Colorado: Colorado Scientific Society Proceedings, v. 15, no. 8, p.338.

Reference (Geology): Christman, R. A., Brock, M. R., Pearson, R. C., and Singewald, Q. D., 1959, Geology and thorium deposits of the Wet Mountains, Colorado - a progress report: U.S. Geological Survey Bulletin 1072-H, p. 491-535.

Reference (Geology): Cappa, J. A., 1998, Alkalic igneous rocks of Colorado and their associated ore deposits: Colorado Geological Survey Resource Series 35, 138 p.

Reference (Geology): Armbrustmacher, T.J., 1984, Alkaline rock complexes in the Wet Mountains area, Custer and Fremont counties, Colorado: U.S. Geological Survey Professional Paper 1269, 33 p.

Reference (Deposit): Armbrustmacher, T.J., 1988, Geology and resources of thorium and associated elements in the Wet Mountains area, Fremont and Custer counties, Colorado: U.S. Geological Survey Professional Paper 1049-F, 34 p.


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