Ralston Buttes District

The Ralston Buttes District is a uranium mine located in Jefferson county, Colorado at an elevation of 6,749 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: Ralston Buttes District

Commodity

Primary: Uranium
Secondary: Copper
Secondary: Molybdenum
Tertiary: Nickel
Tertiary: Cobalt
Tertiary: Zinc
Tertiary: Lead
Tertiary: Silver
Tertiary: Gold
Tertiary: Bismuth
Tertiary: Manganese

Location

State: Colorado
County: Jefferson
District: Ralston Buttes 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

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: District
Operation Category: Producer
Operation Type: Unknown
Year First Production: 1895
Discovery Year: 1884
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: M

Physiography

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

Mineral Deposit Model

Not available

Orebody

Form: LENTICULAR, LINEAR, IRREGULAR

Structure

Type: R
Description: Front Range Uplift, Denver Basin, Idaho Springs-Ralston Shear Zone

Type: L
Description: Rogers, Hurricane Hill, Junction Ranch, And Livingston Fault Systems (Breccia Reefs)

Alterations

Alteration Type: L
Alteration Text: Alteration Of Fe And Cu Minerals And U Ore; Potassic Alteration; Some Silicification

Rocks

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

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

Analytical Data

Analytical Data: ORE SHIPMENTS FROM DISTRICT FROM 1953-1960 RANGED FROM 0.16 TO 1.32% U3O8 WITH OVERALL AVERAGE OF 0.74% U3O8. HIGH-GRADE ORE SAMPLE FROM MENA MINE CONTAINED 10.82% CU, 5.8% BI, AND 43.6 OZ/TON AG. SCHWARTZWALDER MINE SAMPLES CONTAINED AS MUCH AS 1.16% CU, 4.77% MNO, 0.077% V2O5, 0.053% NI, 0.95% MO, 0.050% CO, 0.19% ZN, 1.63% PB, 7.1 OZ/TON AG. SPECTROGRAPHIC ANALYSES SHOWED RELATIVELY HIGH TI, AS, BI, Y, ZR. TRACE AMOUNTS OF NB, AU, YB, GA, CR, BE.

Materials

Ore: Pyrite
Ore: Molybdenite
Ore: Chalcocite
Ore: Sphalerite
Ore: Bornite
Ore: Covellite
Ore: Uranophane
Ore: Coffinite
Ore: Bismuth
Ore: Silver
Ore: Pyrrhotite
Ore: Chalcanthite
Ore: Marcasite
Ore: Galena
Ore: Jordisite
Ore: Niccolite
Gangue: Fluorite
Gangue: Calcite
Gangue: Sericite
Gangue: Barite
Gangue: Chlorite
Gangue: Hematite
Gangue: Limonite
Gangue: Ankerite
Gangue: Quartz

Comments

Comment (Deposit): URANIUM MINERALIZATION CONTROLLED BY N 30 TO 50 W TRENDS OF LARAMIDE BRECCIA REEF FAULTS AND FRACTURES WHERE THEY CROSS HORNBLENDIC, LAYERED CALC-SILICATE, AND MICROCLINE GNEISSES IN PRECAMBRIAN IDAHO SPRINGS FORMATION. AT RALSTON CREEK, PRINCIPAL PITCHBLENDE ORE (SOOTY, MASSIVE, AND COLLOFORM) AND VARIOUS SECONDARY U MINERALS OCCUR IN TRANSITIONAL EPITHERMAL TO MESOTHERMAL VEINS IN FAULT BRECCIAS. THOSE IN GOLDEN GATE CANYON AREA TO SOUTH ARE TYPICAL EPITHERMAL VEINS. U ASSOCIATED WITH MINOR AMOUNTS OF SULFIDES OF CU, PB, ZN, FE, MO, AND NI, WITH SECONDARY CU AND NI MINERALS, NATIVE METALS, AND TRACE AMOUNTS OF AU, V, AND CO. PRINCIPAL GANGUES ARE CARBONATES (ANKERITE AND CALCITE) AND K-FELDSPAR AND COMMON FE STAINING. DEPOSITS RANGE FROM SMALL VEINLETS AND MINERALIZED FAULT BRECCIA TO LARGE ORE SHOOTS CONSISTING OF BRANCHING AND COALESCING VEINS. RICHEST GRADES FOUND IN BRECCIA ON HANGING WALLS AND FOOTWALLS OF REEFS. MINOR OCCURRENCES FOUND ALONG PEGMATITES AND IN SULFIDE-BEARING

Comment (Development): RALSTON CREEK DISTRICT AND EVERGREEN AREA WERE FIRST PROSPECTED IN 1880S AND 1890S FOR CU, WHICH WAS VISIBLE ON OUTCROPS. PROBABLY SOME SMALL SHIPMENTS OF CU ORE MADE. INITIAL DISCOVERY OF PITCHBLENDE PROBABLY MADE BEFORE 1884 BUT WAS THOUGHT TO BE NONECONOMIC. INTERMITTENT MINING OF BERYL AND NONMETALS FROM PEGMATITES IN AREA TOOK PLACE FROM LATE 1800S THRU 1950S. PITCHBLENDE AND TORBERNITE DISCOVERED IN 1949 BY FRED SCHWARTZWALDER, AND SUBSEQUENT DISCOVERIES MADE BY USGS IN EARLY 1950S. AFTER FIRST ORE SHIPMENTS IN 1953, SCHWARTZWALDER MINE HAS BEEN DISTRICT'S LARGEST PRODUCER AND ONE OF LARGEST VEIN U MINES IN NORTH AMERICA. RALSTON CREEK DISTRICT IS FRONT RANGE'S LARGEST URANIUM PRODUCER.

Comment (Geology): SHERIDAN AND OTHERS' (1967) STAGES OF STRUCTURAL EVOLUTION AS FOLLOWS: 1) EARLY PLASTIC FOLDING OF PRECAMBRIAN SEDIMENTARY AND VOLCANIC (?) ROCKS, WITH PROBABLE REGIONAL METAMORPHISM; 2) SECOND PERIOD OF PLASTIC FOLDING AND REGIONAL METAMORPHISM, WITH INTRUSION AND PARTIAL METAMORPHISM OF PRECAMBRIAN IGNEOUS ROCKS; 3) CATACLASTIC DEFORMATION OF IGNEOUS AND METASEDIMENTARY ROCKS IN IDAHO SPRINGS-RALSTON SHEAR ZONE; 4) PROBABLE LATE PRECAMBRIAN MOVEMENT FORMING ANCESTRAL EQUIVALENTS OF NW-TRENDING FAULTS AND FRACTURES; 5) COMPLEX MOVEMENT ALONG NW FAULT SYSTEMS IN LARAMIDE OROGENY (LATE CRETACEOUS TO EARLY TERTIARY) WITH LOCAL DEPOSITION OF HYDROTHERMAL VEINS AND DIKE INTRUSION.

Comment (Deposit): INDIVIDUAL RECORDS PREPARED FOR FOLLOWING MINES AND PROPERTIES: ASCENSION MINE, AUBREY LADWIG MINE, BANKERS LODE CLAIM FORK PROSPECT, LADWIG GROUP, MENA MINE, OHMAN MINE, SCHWARTZWALDER MINE, UNNAMED CU PROSPECT. ; INFO.SRC : 1 PUB LIT

Comment (Deposit): QUART VEINS. FAVORABILITY OF GNEISSES APPARENTLY DUE TO HIGH FE-CONTENT (HORNBLENDE) MINERALS READILY ATTACKED BY SOLUTIONS; SUBSEQUENT PRECIPITATION OF FE PROVIDED EFFECTIVE MECHANISM FOR U DEPOSITION. GENERAL PARAGENESIS, AS DETERMINED AT MENA MINE: 1) FAULTING, BRECCIATION, WALLROCK ALTERATION; 2) K-FELDSPAR DEPOSITION; 3) DEPOSITION OF COARSE- AND FINE-GRAINED ANKERITE; 4) DEPOSITION OF PITCHBLENDE, THEN MINOR QUARTZ; 5) MINOR FRACTURING; 6) DEPOSITION OF LATE ANKERITE, CALCITE, BASE-METAL SULFIDES AND ASSOCIATED METALS. OTHER MINES SHOW THAT OTHER PERIODIC FRACTURING MAY HAVE INTERRUPTED PITCHBLENDE DEPOSITION.

Comment (Workings): MOST MINES DEVELOPED BY SHORT CROSSCUT ADITS AND DRIFTS ON VEIN ON ONE TO FIVE LEVELS; FEW SHAFTS; MINOR OPEN PITTING BEYOND EXPLORATORY SURFACE CUTS. SCHWARTZWALDER, DISTRICT'S DEEPEST MINE, ATTAINED ABOUT 1500-FT DEPTH.

Comment (Location): ALONG RALSTON CREEK AND TRIBUTARIES WEST OF RALSTON BUTTES, ALONG HALFMILE GULCH, AND THE AREAS AT AND 2 MILES BELOW JUNCTION OF TUCKER AND CRAWFORD GULCHES. ELEV AND LAT-LONG GIVEN ARE FOR DISTRICT'S LARGEST MINE, THE SCHWARTZWALDER, IN SE SEC. 25, T 2 S, R 71 W. ; INFO FROM LAND.ST :(1975)

Comment (Production): PARTIAL PRODUCTION RECORD. AMOUNT OF CU FROM EARLY OPERATIONS UNKNOWN BUT CLASSIFIED AS SMALL. AMOUNT OF MO RECOVERED FROM SCHWARTZWALDER ORE AT COTTER CORP.'S CANON CITY MILL UNKNOWN. LB U3O8 NOT CONSISTENTLY REPORTED FOR SCHWARTZWALDER MINE, SO ONLY FIGURES FOR 1972-80 CITED. NO PRODUCTION FROM DISTRICT IN 1954 AND 1965. 1961 FIGURE INCLUDES ESTIMATED TONNAGE FROM ASCENSION MINE; 1971 FIGURE EXCLUDES SMALL UNKNOWN PRODUCTION FROM LADWIG GROUP CLAIMS. TOTAL PRODUCTION IS FROM FOLLOWING MINES FOR RESPECTIVE YEARS: ASCENSION (1956, 1960-63, 1972), AUBREY LADWIG (1955-56), FORK PROSPECT (1964), LADWIG GROUP (1971), MENA (1956-60, 1962), OHMAN (1959-60), SCHWARTZWALDER (1953, 1955-64, 1966-80 AND STILL ACTIVE).

References

Reference (Deposit): ADAMS, J.W., AND OTHERS, 1953, URANIUM OCCURRENCES IN THE GOLDEN GATE CANYON AND RALSTON CREEK AREAS, JEFFERSON COUNTY, COLORADO: USGS CIRC. 320.

Reference (Deposit): ADAMS, J.W., AND STUGARD, FREDERICK, JR., 1956, WALL-ROCK CONTROL OF CERTAIN PITHBLENDE DEPOSITS IN GOLDEN GATE CANYON, JEFFERSON COUNTY, COLORADO: USGS BULL. 1030-G.

Reference (Deposit): NELSON-MOORE, J.L., AND OTHERS, 1978, RAIDOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: CGS BULL. 40, P. 189-196.

Reference (Deposit): SHERIDAN, D.M., AND OTHERS, 1967, GEOLOGY AND URANIUM DEPOSITS OF THE RALSTON BUTTES DISTRICT, JEFFERSON COUNTY, COLORADO: USGS PROF. PAPER 520 (INCLUDES QUAD GEOLOGIC MAP OF RALSTON BUTTES QUAD).

Reference (Deposit): SIMS, P.K., AND SHERIDAN, D.M., 1964, GEOLOGY OF URANIUM DEPOSITS IN THE FRONT RANGE, COLORADO: USGS BULL. 1159.

Reference (Production): SHERIDAN AND OTHERS, 1967, P. 75; COLORADO DIV. MINES ANN. OPERATORS REPTS.

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