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Urad Mine

Past Producer in Clear Creek county in Colorado, United States with commodities Molybdenum, Lead, Zinc, Tungsten, Uranium
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Alteration
  9. Mineral occurrence model information
  10. Host and associated rocks
  11. Nearby scientific data
  12. Geologic structures
  13. Ore body information
  14. Controls for ore emplacement
  15. Economic information about the deposit and operations
  16. Mining district
  17. Land status
  18. Ownership information
  19. Production statistics
  20. Workings at the site
  21. Links to other databases
  22. Bibliographic references
  23. General comments
  24. Reporter information

Geologic information

Identification information

Deposit ID 10012413
MRDS ID D008026
MAS/MILS ID 0080191497
Record type Site
Mineralized Area Henderson/Urad
Current site name Urad Mine

Comments on the site identification

  • *****SEE RELATED DEPOSIT Henderson Deposit ID 10012410

Geographic coordinates

Point of reference Geographic coordinates: Elevation UTM Precision Relative position Point location
-105.82754, 39.7561 (WGS84) 3133 7.7 MILES N 90 W FROM EMPIRE. 54 MILES WEST OF DENVER, NEAR EMPIRE, CO.
(click for info)
-105.82782, 39.7561 (WGS84) 3133 100 7.7 MILES N 90 W FROM EMPIRE. 54 MILES WEST OF DENVER, NEAR EMPIRE, CO.

Site location context

Political divisions (FIPS codes)

Clear Creek(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Berthoud Pass(quadrangle 1:24,000 scale)

Denver West(quadrangle 1:100,000 scale)

Denver(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Clear(hydrologic unit)

South Platte(hydrologic accounting unit)

South Platte(hydrologic subregion)

Missouri(hydrologic region)

Federal lands

Arapaho and Roosevelt National Forests(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Colorado Clear Creek

Public Land Survey System information

Meridian Township Range Section Fraction State
6th Principal 003S 075W 30 SE Colorado

Comments on the location information

  • 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)

Commodities

Commodity Importance
Molybdenum Primary
Lead Tertiary
Zinc Critical Tertiary
Tungsten Critical Tertiary
Uranium Tertiary

Comments on the commodity information

  • 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)

Materials information

Materials Type of material
Molybdenite Ore
Ferrimolybdite Gangue
Fluorite Gangue
Galena Gangue
Huebnerite Gangue
Pyrite Gangue
Quartz Gangue
Sericite Gangue
Sphalerite Gangue
Rhodochrosite Gangue

Alteration

  • (Local) Silicification, Sericitization, K-Feldspathization

Analytical data

Result 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

Mineral occurrence model information

Model code 50
USGS model code 16
Deposit model name Climax Mo

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Granitoid
    Rock unit name Square quartz porphyry
    Stratigraphic age (youngest) Oligocene
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid
    Rock unit name Tungsten Slide unit
    Stratigraphic age (youngest) Oligocene
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Granite
    Rock type qualifier 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
    Rock unit name Silver Plume Granite
    Stratigraphic age (youngest) Oligocene
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite
    Rock type qualifier 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
    Rock unit name Red Mountain Complex- multi-phase intrusive complex of high silica, alkali-rich rhyolite, and granite porphyry
    Stratigraphic age (youngest) Mesoproterozoic

Nearby scientific data

(1) -105.82754, 39.7561
ListMap
(2) -105.82782, 39.7561
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Straight Cr., Vasquez Cr., Loveland Pass-Berthoud Pass Fault Zones, Main Fissure
Type of structure Regional
Structure description Front Range Uplift, Silver Plume Batholith, Colorado Mineral Belt

Ore body information

  • General form CYLINDRICAL OR PIPELIKE
    Thickness 335.28M
    Length 365.76M
    Width 152.4M
    Depth to bottom 335.28M

Comments on the ore body information

  • 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

Controls for ore emplacement

  • Cone Sheet Fracture Zone In Roof Of Multiple-Stage Intrusion

Comments on the geologic information

  • 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)
  • 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.

Economic information about the deposit and operations

Operation type Underground
Development status Past Producer
Commodity type Metallic
Deposit size Medium
Significant Yes
Discovery year 1910
Year of first production 1915
Year of last production 1974

Mining district

District name Empire District; Daley; Dailey; Jones Pass
District name Henderson/Urad

Land status

Ownership category Private

Ownership information

  • Type Owner-Operator
    Owner Climax Molybdenum Co., Division Of American Metal Climax Inc. (Amax)
    First year 1981

Production statistics

  • Year 1971
    Accuracy Accurate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major MoS2 Molybdenum Molybdenum 0wt-pct
  • Year 1974
    Period 1915-1974
    Material 25,000 tons Metal recovered
    Ore mined 10000000mt
    Accuracy Estimate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major MoS2 Ore Molybdenum Molybdenum 0wt-pct

Comments on the production information

  • 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).
  • 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)

Comments on the reserve resource information

  • The Urad deposit is depleted (mined out).

Workings at the site

  • Type of workings Underground
    Overall depth 502.92M

Comments on the workings information

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

Comments on 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.

Reference information

Bibliographic references

General comments

Subject category Comment text
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.
Deposit Discovery Year: EARLY 1900S

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-81 Schwochow, Stephen D. (King, Robert U.) Colorado Geological Survey
Updater 24-MAY-06 Beach, Richard A. Colorado Geological Survey
Updater 03-AUG-07 Melton, Greg U.S. Geological Survey
Editor 20-JUN-11 Wilson, Anna B U.S. Geological Survey merged and deleted duplicate reocrds 10010114 (D003620) and 10166596 (D008026 and 008019497)
Reporter 01-AUG-78 Hassler, J. William U.S. Geological Survey MRDS D003620 = newMRDS 10010114
Reporter 17-NOV-83 Intermountain Field Operations Center (IFOC) U.S. Bureau of Mines MAS 0080191497 = newMRDS 10166596

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

External references

Maps centered on this site

Authoritative Colorado resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.