Urad Mine

Site Name

Primary: Urad Mine

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Commodity

Primary: Molybdenum
Tertiary: Lead
Tertiary: Uranium
Tertiary: Tungsten
Tertiary: Zinc

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Location

State: Colorado
County: Clear Creek
District: Henderson/Urad

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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: Underground

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Ownership

Owner Name: Climax Molybdenum Co., Division Of American Metal Climax Inc. (Amax)
Years: 1981 -

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Production

Year: 1974
Time Period: 1915-1974
Mined: 10000000.000 mt
Material type: 25,000 tons Metal recovered
Year: 1971

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Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Climax Mo
Operation Type: Underground
Year First Production: 1915
Year Last Production: 1974
Discovery Year: 1910
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: Y
Deposit Size: M

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Physiography

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

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Mineral Deposit Model

Model Name: Climax Mo

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Orebody

Form: CYLINDRICAL OR PIPELIKE

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Structure

Type: R
Description: Front Range Uplift, Silver Plume Batholith, Colorado Mineral Belt

Type: L
Description: Straight Cr., Vasquez Cr., Loveland Pass-Berthoud Pass Fault Zones, Main Fissure

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Alterations

Alteration Type: L
Alteration Text: Silicification, Sericitization, K-Feldspathization

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Rocks

Name: Granite
Role: Host
Description: Composite batholith of 200 sq. mi in diamension that intrudes the metasedimentary schists of the Idaho Springs Formation. A coarse grained massive to trachytoid, slightly porphyritic biotite-muscovite granite and a fine-to medium-grained variant
Age Type: Host Rock
Age Young: Oligocene

Name: Granitoid
Role: Host
Age Type: Host Rock
Age Young: Oligocene

Name: Granitoid
Role: Host
Age Type: Host Rock
Age Young: Oligocene

Name: Rhyolite
Role: Associated
Description: 7 units- oldest to youngest:Tungsten Slide; East Knob; Square quartz porphyry; Rhyolite porphyry of radial dike swarm; Red Mtn. porphyry; Urad porphyry; Primos porphyry; Henderson granite
Age Type: Associated Rock
Age Young: Mesoproterozoic

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Analytical Data

Analytical Data: AVG. GRADE FOR 1918-19 UNDER PRIMOS CHEMICAL CO. WAS 0.975 % MOS2, AVG. GRADE FOR 1944-46 UNDER MOLYBDENUM CORP. OF AMERICA WAS 0.579 % MOS2. AVG. GRADE FOR 1967-74 UNDER AMAX WAS 0.344 % MOS2. OVERALL AVG. GRADE 0.348 % MOS2. THREE GRAB SAMPLES GAVE VALUES OF 0.002 TO 0.15 % EQUIV. U3O8

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Materials

Ore: Molybdenite
Gangue: Ferrimolybdite
Gangue: Fluorite
Gangue: Galena
Gangue: Huebnerite
Gangue: Pyrite
Gangue: Quartz
Gangue: Sericite
Gangue: Sphalerite
Gangue: Rhodochrosite

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Comments

Comment (Identification): *****SEE RELATED DEPOSIT Henderson Deposit ID 10012410

Comment (Orebody): The Urad orebody and Urad mineralized zone are related to the Square quartz porphyry phase of the Red Mountain Complex. The orebody occures as a stockwork localized by a main fissure and related faults and fracture zones and is cylindrical in shape. The mineralization is hosted equally in the Square quartz porphyry, the Tungsten slide unit and Precambrian Silver Plume granite. Ore occures as thin quartz-molybdenite veins and veinlet forming a stockwork in brecciated and crackled zones, in breccia dikes and on joint surfaces. Molybdenite is very fine grained and intergrown with varying amounts of quartz, sericite, pyrite and fluorite. Intrusion of the Red Mountain porphyry phase, the principal unit of the Red Mountain Complex, destroyed much of the Square quartz porphyry, a large part of the Urad mineralized zone and part of the Urad orebody.(Wallace and others, 1978) Hydrothermal alteration zones include: potassium feldspar, quartz-sericite-pyrite, argillic and propylitic zones

Comment (Location): PORTAL IS AT SOUTHEAST BASE OF RED MTN. ON WOODS CREEK 1 MILE FROM WEST FORK CLEAR CR. CONFLUENCE, AND 8 MILES WEST OF EMPIRE, IN SEC. 30, T 3 S, R 75 W. INFO FROM LAND.ST :(1978)

Comment (Geology): The Urad orebody was hosted in Oligocene and Precambrian granitic rocks on the SW side of Red Mountain; it was arcuate in plan view, with a length of 1200 ft, width of 500 ft, and depth of 950 ft.

Comment (Deposit): Discovery Year: EARLY 1900S

Comment (Development): SHALLOW CUTS WERE MADE IN OUTCROPPING FERRIMOLYBDENITE IN EARLY 1900S, BUT NO SIGNIFICANT DEVELOPMENT WAS MADE UNTIL 1914. PRIMOS CHEMICAL CO. SHIPPED CONCENTRATES IN 1918-19. PROPERTY PURCHASED IN 1921 BY VANADIUM CORP. OF AMERICA. IN 1941 MINE REOPENED UNDER CONTROL OF MOLYBDENUM CORP. OF AMERICA, WHICH PRODUCED CONCENTRATES FROM 200-TPD MILL FROM 1944-46. IN 1961 AMAX SECURED LEASES, PURCHASED PROPERTY IN 1963, AND BEGAN PRODUCTION IN 1967. OREBODY DEPLETED AND MINE CLOSED IN 1974. MINE WAS SEALED, SURFACE FACILITIES REMOVED, AND TAILINGS POND RECLAIMED.

Comment (Commodity): ZN, PB, W IN ORE WERE TOO LOW GRADE TO BE ECONOMICALLY RECOVERED. GRAB SAMPLES CONTAINED LOW AMOUNTS OF U3O8, UP TO 0.037%. (CGS BULL.40)

Comment (Production): The mine produced nearly 50 million lb. of molybdenum from 14 million tons of ore; most of it was produced from 1967-1974. (Wallace and others, 1978)

Comment (Reserve-Resource): The Urad deposit is depleted (mined out).

Comment (Deposit): DIFFERENT ORE GRADE ZONES FROM CUTOFF OF 0.2% MOS2 TO 0.4+ % MOS2 DEFINE CYLINDRICAL SHAPE IN PROFILE AND AN ARCUATE PLAN. OREBODY FORMED IN CONE SHEET FRACTURES ON AND AROUND CAP OF MULTIPLE-INTRUSIVE STOCK. LATER IT WAS PARTLY TRUNCATED BY INTRUSION OF YOUNGER RED MOUNTAIN PORPHYRY. MOS2 OCCURS PRIMARILY AS VEINLETS (REPLACEMENT AND OPEN-SPACE FILLING) AND SECONDARILY AS JOINT COATINGS AND LENTICULAR POCKETS.

Comment (Workings): MINE DEVELOPED ON 6 LEVELS AT FOLLOWING APPROX. ELEVATIONS: N (11545), M (11460), L (11350), K (11210), H (11000), A OR PORTAL LEVEL (10280).

Comment (Geology): The Urad and Henderson stockwork molybdenite orebodies at Red Mountain are two separate but related deposits. The Urad orebody was formed first at a shallow depth, the Henderson formed deeper within the igneous complex, and is the larger. Together they constitute one of the largest concentrations of molybdenite in the world. The Urad and Henderson deposits at Red Mountain are related to a Oligocene multi-phase rhyolitic intrusive center named the Red Mountain Complex that intrudes the Precambrian Silver Plume Granite batholith within a northeast trending Precambrian shear zone, near the western edge of the Colorado Mineral Belt. The intrusion of the Red Mountain Complex is closely related to the two major northeast-trending Tertiary faults, the Berthoud Pass and the Vasquez Pass. (Wallace and others, 1978)

Comment (Production): ORE TONNAGE FOR 1918-19 TOTALS 71,300 ST AS REPORTED BY WALLACE AND OTHERS (1978). BREAKDOWN IN TABLE IS BASED ON RELATIVE PROPORTION OF EACH YEAR'S CONCENTRATES AS REPORTED BY COLO. DIV. MINES. ESTIMATED LB MO METAL FOR 1918, 1919, 1944, 1945 CALCULATED FROM CONCENTRATE TONNAGE AND GRADE. ESTIMATED LB MO METAL FOR 1946 CALCULATED FROM ORE TONNAGE AND GRADE. CUMULATIVE ORE TONNAGE TOTAL INCLUDES APPROX. 2000 ST ORE HAND-COBBED IN 1915 (WALLACE AND OTHERS, 1978).

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References

Reference (Deposit): WALLACE, S.R., Mackensie, W.B., Blair, R.G., and Muncaster, Neil, 1978, GEOLOGY OF THE URAD AND HENDERSON MOLYBDENITE DEPOSITS, CLEAR CREEK COUNTY, COLORADO, WITH A SECTION ON A COMPARISON OF THESE DEPOSITS WITH THOSE AT CLIMAX, COLORADO: ECONomic GEOLOGY, V. 73, no. 3, P. 325-368.

Reference (Production): COLO. DIV. MINES ANN OPERATOR REPORTS; ANNUAL ITEM 15: AMAX.

Reference (Deposit): OCT, 1967, NEW URAD MOLY MINE IS BLOCK-CAVED FOR 3-STAGE UNDER GROUND CRUSHING: ENGINEERING & MINING JOURNAL.

Reference (Deposit): OCT, 1967, URAD MINE DEDICATION MARKS OFFICIAL STARTUP OF NEW MOLY PRODUCER: MINING ENGINEERING.

Reference (Deposit): SKILLINGS, J.B., 1967, CLIMAX MOLYBDENUM CO. DEDICATES URAD MINE IN COLO. SEPT. 14: SKILLINGS MINING REVIEW.

Reference (Deposit): COLORADO DIV. MINES ANN. OPERATOR REPTS.

Reference (Commodity): Nelson-Moore, J.L., Collins, D.B., and Hornbaker, A.L., 1978, Radioactive mineral occurrences of Colorado: Colorado Geological Survey Bulletin 40, 1054 p., 12 pl.

Reference (Deposit): VANDERWILT, J.W., 1947, MISCELLANEOUS METALS--MOLYBDENUM, IN MINERAL RESOURCES OF COLORADO: COLORADO MINERAL RESOURCES BD., P. 222-226.

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