South Platte Pegmatite District

The South Platte Pegmatite District is a feldspar and quartz mine located in Jefferson county, Colorado at an elevation of 7,402 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: South Platte Pegmatite District

Commodity

Primary: Feldspar
Primary: Quartz
Secondary: Fluorine-Fluorite
Secondary: REE
Secondary: Gemstone
Tertiary: Thorium
Tertiary: Niobium (Columbium)
Tertiary: Tantalum
Tertiary: Manganese

Location

State: Colorado
County: Jefferson
District: South Platte Pegmatite District

Land Status

Land ownership: National Forest
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

Ownership

Not available

Production

Not available

Deposit

Record Type: District
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1935
Year Last Production: 1965
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains

Mineral Deposit Model

Not available

Orebody

Form: LENTICULAR

Form: LENTICULAR

Structure

Type: R
Description: Front Range Uplift, Pikes Peak Batholith

Type: L
Description: Kennedy Gulch Fault Zone

Alterations

Alteration Type: L
Alteration Text: Fe Oxidation In Biotite, Chloritization, Sericitization, Deuterogenic Wallrock Alt., 2d Hydrothermal Repl.

Rocks

Name: Pegmatite
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic

Name: Pegmatite
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic

Analytical Data

Analytical Data: SIMMONS AND HEINRICH, 1980).
Analytical Data: QUARTZ MONZONITE SAMPLES CONTAINED 124 TO 152 PPM LA, 254 TO 307 PPM CE, 21 TO 28 PPM SM, 0.9 TO 3 PPM TB, 7 TO 23 PPM YB, 4 TO 6.5 PPM LU. OVERALL MEAN VALUES FOR GRANITE, QUARTZ MONZONITE, AND NEAR-CONTACT ZONE AT SEERIE MINE WERE 128.7 PPM LA, 259.8 PPM CE, 27.3 PPM SM, 1.9 PPM TB, 15.5 PPM YB, 5.7 PPM LU. ENRICHMENT FACTORS CALCULATED TO BE 2.3 FOR LA, 2.5 FOR CE, 3.4 FOR SM, 1.7 FOR TB, 3.6 FOR YB, 8.4 FOR LU. RARE-EARTH CONCENTRATES FROM BIG BEAR NO. 2 AND OTHER PEGMATITES CONTAINED 47.9% Y, 2.8% GD, 2.3% DY, 3.7% ND, 1 TO 2% ER, SM, CE, AND 0 TO 1% HO, LA, TB, PR (HEINRICH, 1958
Analytical Data: WHOLE-ROCK NEUTRON-ACTIVATION ANALYSES OF GRANITE SAMPLES IN AREA CONTAINED 87 TO 189 PPM LA, 177 TO 395 PPM CE, 15 TO 38 PPM SM, 0.5 TO 2.9 PPM TB, 4 TO 25 PPM YB, 4 TO 8 PPM LU

Materials

Ore: Quartz
Ore: Fluorite
Ore: Xenotime
Ore: Gadolinite
Gangue: Sericite
Gangue: Amazonstone
Gangue: Muscovite
Gangue: Limonite
Gangue: Zircon
Gangue: Fergusonite
Gangue: Thalenite
Gangue: Doverite
Gangue: Synchisite
Gangue: Pyrolusite
Gangue: Biotite
Gangue: Hematite
Gangue: Prochlorite
Gangue: Topaz
Gangue: Pyrite
Gangue: Calcite
Gangue: Bastnaesite
Gangue: Yttrotantalite

Comments

Comment (Deposit): LEVELS TED TO BE LIMITED TO QUARTZ CORE AND WALL ZONE. EXPOSURE SIZE AND ZONE DEVELOPMENT COULD THUS BE GOVERNED BY ELEVATION AND DEPTH OF EROSION. LARGER LENS- AND POD-SHAPED PEGMATITES SHOW WELL DEVELOPED MOSTLY CONCENTRIC ZONING: 1) POORLY DEVELOPED OR ABSENT BORDER ZONE OF GRAPHIC GRANITE AND INTERGROWN QUARTZ-MICROCLINE PERTHITE; 2) WALL ZONE OF BIOTITE GRAPHIC GRANITE WITH INTERGROWN QUARTZ AND MICROCLINE-PERTHITE; 3) OUTER INTERMEDIATE ZONE OF GIANT BIOTITE CONTAINING AGGREGATES OF CYRTOLITE-THORITE AND FERGUSONITE; 4) MIDDLE INTERMEDIATE ZONE OF GIANT MICROCLINE-PERTHITE (MINED ZONE); 5) INNER INTERMEDIATE OR CORE-MARGIN ZONE OF DISCONTINUOUS GREEN EUHEDRAL FLUORITE WITH SOME TOPAZ; 6) CORE OF MASSIVE QUARTZ OR QUARTZ-MICROCLINE. SECONDARY REPLACEMENT UNITS SUPERPOSED ON PRIMARY ZONAL SEQUENCES: 1) PERTHITE REPLACED BY ALBITE AND CLEAVELANDITE; 2) BIOTITE BY HEMATITE; 3) QUARTZ BY SERICITE; 4) FLUORITE BY YTTROFLUORITE; 5) YTTROFLUORITE BY DOVERITE AND THALENITE; 6) GADOLINITE

Comment (Deposit): BY Y-FLUOROCARBONATE; 7) QUARTZ ND ALLANITE BY LATE FLUORITE. MINOR MINERALIZATION TYPE IS FLUORITE-CEMENTED BRECCIA IN FRACTURES.

Comment (Workings): ALL OPEN CUTS. FOR THOSE PRODUCING ONLY FELDSPAR, PERTHITE FROM INTERMEDIATE ZONE SELECTIVELY MINED LEAVING ANNUAL OR PARTLY ANNULAR EXCAVATION AROUND INTACT QUARTZ CORE.

Comment (Deposit): DETAILED RECORDS PREPARED FOR THOSE PEGMATITES PRODUCING RAE: BIG BEAR NO. 2, BIG BERTHA, DAZIE BELL, LITTLE PATSY, LUSTER NO. 1, MADONNA, OREGON NO. 3, SHUTTLE RUN, AND WHITE CLOUD MINES. SNOWFLAKE MINE RECORD ALSO INCLUDED FOR RAE BUT IS REMOVED FROM IMMEDIATE DISTRICT AND LOCATED IN TELLER CO. ; INFO.SRC : 1 PUB LIT

Comment (Location): AROUND RALEIGH PEAK SW OF CONFLUENCE OF SOUTH PLATTE RIVER AND ITS NORTH FORK. SECTIONS GIVEN ARE FOR RAE-PRODUCING MINES. OTHER FLD/QTZ PEGMATITES LIE IN SECS. 16, 17, 21, 26, 27, 29, 32, 34, & 35, T7S, R70W AND SECS. 01, 04, T8S, R70W. LAT-LONG GIVEN IS FOR CENTRALLY LOCATED RALEIGH PEAK. ; INFO FROM LAND.ST :(1975)

Comment (Production): ANNUAL TOTALS FOR FLD, QTZ, AND F UNAVAILABLE DUE TO LACK OF PRODUCTION STATISTICS FROM INDIVIDUAL MINES. CUMULATIVE TOTALS ARE ROUGH ESTIMATES FROM SIMMONS AND HEINRICH (1980). TOTAL ESTIMATED RAE IS 55 ST FROM WHITE CLOUD MINE, 16 ST FROM DEEP HOLE MINE, AND POSSIBLY UP TO 100 ST FROM BIG BEAR NO. 2 AND SEVERAL OTHERS MINES.

Comment (Development): AREA PROBABLY FIRST PROSPECTED FOR AU BECAUSE OF BULL QUARTZ CORES EXPOSED. PROSPECTED AT LEAST SINCE 1920S FOR FELDSPAR. INTERMITTENT PRODUCTION OF FELDSPAR AND QUARTZ TERRAZZO AND DECORATIVE STONE FROM LATE 1930S TO LATE 1960S. SMALL PRODUCTION OF ACID-GRADE FLUORSPAR. RARE-EARTH ORES DISCOVERED IN MID 1950S AND SMALL AMOUNT OF RARE EARTHS AND RARE-EARTH FLUORITE PRODUCED.

Comment (Deposit): NORTH END OF PIKES PEAK BATHOLITH RELATIVELY CONFORMABLY INTRUDES OLDER METAMORPHICS ON CONTACT TRENDING ABOUT N 40 W, 40 NE. WEAKLY DEVELOPED FLOW STRUCTURE IN GRANITE ROUGHLY PARALLELS CONTACT. PEGMATITES BELIEVED TO BE PENECON-TEMPORANEOUS WITH GRANITE EMPLACEMENT AS H2O-RICH LIQUID SEGREGATIONS BECAUSE PEGMATITES ALL CONTAINED WITHIN PLUTON AND DO NOT EXTEND BEYOND BOUNDARY AND BECAUSE NO APPARENT EFFECT (CRYSTAL ORIENTATION, RADIAL FRACTURES, DISTORTION) ON ADJACENT GRANITE. FOUR TYPES OBSERVED: 1) APLITE WITH CONCENTRIC ZONED PEGMATITE OF SIMPLE BIOTITE GRANITE COMPOSITION; 2) SIMPLE QUARTZ-PERTHITE LENS ALONG QUARTZ VEIN; 3) QUARTZ-PERTHITE-BIOTITE PEGMATITE AS FLAT DIKELIKE BODIES RELATED TO FISSURES; 4) LARGE COMPLEX INTERNALLY ZONED PEGMATITES WITH QUARTZ CORES. VARIATIONS IN EXPOSED SIZE AND IN CORE-TO-PEGMATITE SIZE RATIO POSSIBLY DUE TO VERTICAL ASYMMETRY--NARROWER AT BOTTOM FLARING UPWARD WITH INTERMEDIATE ZONE AND RAE/F REPLACEMENT BETTER DEVELOPED NEAR TOP. LOWER

References

Reference (Deposit): SIMMONS, W.B., AND HEINRICH, E.W., 1980, RARE-EARTH PEGMATITES OF THE SOUTH PLATTE DISTRICT, COLORADO: CGS RESOURCE SER. 11, 131 P.

Reference (Deposit): PETERSON, W.L., 1964, GEOLOGY OF THE PLATTE CANYON QUADRANGLE, COLORADO: USGS BULL. 1181-C, 23 P., 1 PL.

Reference (Deposit): HAYNES, C.V., JR., 1965, GENESIS OF THE WHITE CLOUD AND RELATED PEGMATITES, SOUTH PLATTE AREA, JEFFERSON COUNTY, COLORADO: GSA BULL., V. 76, NO. 4, P. 441-462.

Reference (Deposit): ADAMS, J.W., AND SHARP, W.N., 1972, THALENITE AND ALLANITE DERIVED FROM YTTROFLUORITE IN THE WHITE CLOUD PEGMATITE, SOUTH PLATTE AREA, COLORADO: USGS PROF. PAPER 800-C, P. C63-C69.

Reference (Deposit): HEINRICH, E.W., 1958, RARE-EARTH PEGMATITES OF THE SOUTH PLATTE-LAKE GEORGE AREA, DOUGLAS, TELLER, AND PARK COUNTIES, COLORADO (ABS.): GSA BULL., V. 69, NO. 12, PT. 2, P. 1579-1580.

Reference (Deposit): HAYNES, C.V., JR., 1958, RARE-EARTH MINERALIZATION IN THE WHITE CLOUD MINE NEAR SOUTH PLATTE, JEFFERSON COUNTY, COLORADO (ABS.): GSA BULL., V. 69, NO. 12, PT. 2, P. 1729-1730.

Reference (Deposit): ADAMS, J.W., AND OTHERS, 1962, THALENITE FROM TELLER COUNTY, COLORADO: USGS PROF. PAPER 450-D, P. D6-D8.

Reference (Production): SIMMONS AND HEINRICH, 1980

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