Malachite Mine

Site Name

Primary: Malachite Mine
Secondary: Claims: Malachite
Secondary: Morrison

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Commodity

Primary: Gold
Primary: Copper
Primary: Silver
Secondary: Zinc
Tertiary: Lead
Tertiary: Nickel

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Location

State: Colorado
County: Jefferson
District: Malachite District

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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.

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Holdings

Not available

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Workings

Type: Surface/Underground

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Ownership

Owner Name: Colorado Kansas Syndicate
Home Office: Idledale, Co.
Years: 1964 -

Owner Name: Frobex Ltd.
Home Office: Toronto
Years: 1964 -

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1888
Discovery Year: 1866
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

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Physiography

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

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Mineral Deposit Model

Not available

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Orebody

Form: LENTICULAR, TABULAR, PIPE, PINCH AND SWELL

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Structure

Type: R
Description: Front Range Uplift, Denver Basin

Type: L
Description: Bear Creek Shear Zone, Floyd Hill Fault Zone

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Alterations

Alteration Type: L
Alteration Text: Oxidation Of Cu Ore Mineral

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Rocks

Name: Quartz Monzonite
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic

Name: Quartz Monzonite
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic

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Analytical Data

Analytical Data: AVERAGE SMELTER ASSAYS RAN 3.31% CU, 3.43% ZN, 0.90 OZ/TON AG, 0.06 OZ/TON AU. SIX SAMPLES FROM OUTCROP GOSSAN ASSAYED TRACE TO 0.04 OZ/TON AU AND 0.4 TO 0.8 OZ/TON AG (MOREHOUSE, 1950).

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Materials

Ore: Tenorite
Ore: Sphalerite
Ore: Pyrite
Ore: Galena
Gangue: Augite
Gangue: Labradorite
Gangue: Apatite

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Comments

Comment (Production): PARTIAL PRODUCTION RECORD. ANNUAL FIGURES BEFORE 1940 NOT AVAILABLE.

Comment (Development): FIRST CLAIMS FILED 1866. OXIDIZED ORE MINED 1888-1893 FROM SHAFT. THEN WEST AND UPPER EAST TUNNELS DRIVEN. LOWER EAST TUNNEL DRIVEN AFTER CSM GEOPHYSICS STUDENTS DISCOVERED PROMINENT MAGNETIC ANOMALY IN 1938. FOLLOWING PRODUCTION IN 1940-41 BY ASSOCIATED METALS, ASARCO ACQUIRED PROPERTY AND OUTLINED NEW ORE FROM 8 DIAMOND-DRILL HOLES. USGS DID GEOCHEMICAL PROSPECTING IN MID 1950S, FOLLOWED BY FURTHER SURFACE DEVELOPMENT. LAST REPORTED ACTIVITY WAS CORE DRILLING IN 1964.

Comment (Workings): OLD SHAFT 130 FT DEEP. WEST TUNNEL DRIVEN GENERALLY NORTH APPROX 370 FT TO CONNECT WITH OLD SHAFT WORKINGS. UPPER EAST TUNNEL DRIVEN WNW APPROX 270 FT. LOWER EAST TUNNEL DRIVEN NW APPROX 80 FT; SEVERAL WINZES AND RAISES; NUMEROUS SURFACE PROSPECTS AND BULLDOZER CUTS; 2704 FT OF DIAMOND-DRILL HOLES.

Comment (Deposit): INTERLAYERED BIOTITE-AMPHIBOLITE SCHIST AND HORNBLENDE GNEISS TREND GENERALLY EAST-WEST WITH STEEP SW AND NE FOLIATION DIP. LAYERS ARE CUT BY SWARM OF GENERALLY N 30 TO 55 E TRENDING PEGMATITES. WEST ORE BODY IS AVERAGE 40-FT-DIAM PIPELIKE BODY PLUNGING STEEPLY NW. EAST ORE BODY IS 40-FT-WIDE TABULAR BODY WITH EAST-WEST STRIKE AND SOUTH DIP. ORE IS COARSE-GRAINED MASSES OF CHALCOPYRITE, SPHALERITE, AND PYRRHOTITE AND LIES IN LENTICULAR, TABULAR, AND PINCH-AND-SWELL SEGREGATIONS AND SOME REPLACEMENTS IN METAMORPHOSED GABBRO (AS INTERPRETED BY LOVERING AND GODDARD, 1950), ALTHOUGH SYNGENETIC MAGMATIC ORIGIN NOT CONCLUSIVELY ESTABLISHED. HUFF (1963) FOUND ORE TO FILL FRACTURES AND INTERSTICES OF ANGULAR COUNTRY ROCK FRAGMENTS AND, ON BASIS OF FAULT CONTROL AND RELATIVELY NARROW GEOCHEMICAL ANOMALY, BELIEVED DEPOSIT TO BE HYDROTHERMAL VEIN. LARAMIDE AGE COULD THEN BE INTERPRETED ON BASIS OF POSSIBLE RELATION OF FAULT TO NW-TRENDING BRECCIA REEF NEARBY.

Comment (Location): HIGH ON NORTH SIDE OF BEAR CREEK. ELEV AND LAT-LONG GIVEN ARE FOR PORTAL OF LOWER EAST TUNNEL. ; INFO FROM LAND.ST :(1975)

Comment (Ownership): OWN/OP: KANSAS COLO.'MINING CO. [copied from deleted record 10142442].

Comment (Production): PRODUCED IN 1940-41 PROD- 638R T ORE - 306000 16 CO 3100 O [copied from deleted record 10142442].

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References

Reference (Deposit): SHERIDAN, D.M., AND OTHERS, 1972, GEOLOGIC MAP OF THE EVERGREEN QUADRANGLE, JEFFERSON COUNTY, COLORADO: USGS MAP I-786-A.

Reference (Deposit): HEILAND, C.A., AND OTHERS, 1945, GEOPHYSICAL SURVEYS AT THE MALACHITE MINE, JEFFERSON COUNTY, COLORADO: AIME TECH. PUB. 1947.

Reference (Deposit): HUFF, L.C., 1963, COMPARISON OF GEOLOGICAL, GEOPHYSICAL, AND GEOCHEMICAL PROSPECTING METHODS AT THE MALACHITE MINE, JEFFERSON COUNTY, COLORADO: USGS BULL. 1098-C.

Reference (Deposit): LINDGREN, WALDEMAR, 1908, NOTES ON COPPER DEPOSITS IN CHAFFEE, FREMONT, AND JEFFERSON COUNTIES, COLO.: USGS BULL. 340, P. 157-174.

Reference (Deposit): MOREHOUSE, G.E., 1950, GEOLOGY OF THE MALACHITE MINE, JEFFERSON COUNTY, COLORADO: COLORADO SCHOOL OF MINES M.SC. THESIS T-675.

Reference (Deposit): LOVERING, T.S., AND GODDARD, E.N., 1950, GEOLOGY AND ORE DEPOSITS OF THE FRONT RANGE, COLORADO: USGS PROF. PAPER 223, P. 64, 68.

Reference (Production): MOREHOUSE (1950)

Reference (Deposit): "MINERAL RESOURCES OF COLO." MINE MAP REPO # 403134 [copied from deleted record 10142442]

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