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Leonard Mine

Occurrence in Douglas county in Colorado, United States with commodity Manganese
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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. Host and associated rocks
  9. Nearby scientific data
  10. Geologic structures
  11. Ore body information
  12. Economic information about the deposit and operations
  13. Mining district
  14. Land status
  15. Links to other databases
  16. Bibliographic references
  17. General comments
  18. Reporter information

Geologic information

Identification information

Deposit ID 10094571
MRDS ID D009446
Record type Site
Current site name Leonard Mine
Related records 10239153

Geographic coordinates

Geographic coordinates: -104.75278, 39.39056 (WGS84)
Elevation 1859
Location accuracy 10000(meters)
Relative position 5 MILES ENE OF CASTLE ROCK

Site location context

Political divisions (FIPS codes)

Douglas(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Castle Rock North(quadrangle 1:24,000 scale)

Castle Rock(quadrangle 1:100,000 scale)

Denver(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Middle South Platte-Cherry Creek(hydrologic unit)

South Platte(hydrologic accounting unit)

South Platte(hydrologic subregion)

Missouri(hydrologic region)

Geographic areas

Country State County
United States Colorado Douglas

Public Land Survey System information

Meridian Township Range Section Fraction State
6th Principal 008S 066W Colorado

Comments on the location information

  • LOCATION CITED AS FRANKTOWN BUT EXACT POSITION UNKNOWN. LAT-LONG GIVEN IS FOR FRANKTOWN ; INFO FROM LAND.ST :(1974)

Commodities

Commodity Importance
Manganese Critical Primary

Comments on the commodity information

  • OTHER UNSPECIFIED MN OXIDES PRESENT IN SMALL AMOUNTS

Materials information

Materials Type of material
Psilomelane Ore
Barite Gangue
Limonite Gangue

Analytical data

Result LEONARD MINE SAMPLE ASSAYED 10.8 % MN, 72.2 % INSOL, 55.9 % SIO2, 1.2 % FE, 1.7 % CAO, LT 0.05 % S, 2.6 % BA, 9.2 % AL203, 0.25 % ZN, 0.03 % P.
Result COMPOSITE OF LEONARD MINE SAMPLE AND TWO BUCKLEY FIELD (ARAPAHOE CO.) SAMPLES ASSAYED 11.1 % MN, 71.4 % INSOL, 56.7 % SIO2, 1.2 % FE, 1.3 % CAO, LT 0.05 % S, 3.0 % BA, 8.0 % AL203, 0.23 % ZN, 0.03 % P.
Result SIZING OF CRUSHED COMPOSITE SAMPLE GAVE MN DISTRIBUTION OF 77.7 % IN PLUS 10-MESH AND 22.3 % IN MINUS 10-MESH.
Result COMPOSITE SAMPLE CRUSHED TO MINUS 10-MESH, STAGE-GROUND THRU 48 MESH, SIZED AND TABLED GAVE MN DISTRIBUTION OF 57.2 % IN FIRST CONCENTRATE (14.0 WT % ASSAYING 42.8 % MN AND 7.6 % SIO2), 15.7 % IN SECOND CONCENTRATE (4.1 WT % ASSAYING 40.1 % MN AND 10.2 % SIO2), 9.9 % IN MIDDLING (6.9 WT % ASSAYING ING 15.0 % MN AND 53.3 % SIO2), 4.9 % IN SLIMES (7.4 WT % ASSAYING 7.0 % MN AND 50.2 % SIO2), 12.3 % IN TAILING (67.6 WT % ASSAYING 1.9 % MN AND 73.0 % SIO2).
Result SINTERING TEST YIELDED 48.4 % MN, 1.9 % FE, 9.2 % SIO2, 3.4 % AL203, 1.2 % CAO, 0.1 % ZN, 0.056 % P, 11.0 % BA.
Result STAGE CRUSHING TEST ON 0.5-INCH ORE YIELDED MN DISTRIBUTION OF 60.0 % IN TABLE CONCENTRATE, 5.0 % IN TAILING, 12.5 % IN TABLE SLIME, 22.5 % IN MINUS 10-MESH REJECT

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone
    Rock unit name Dawson Formation
    Rock description Dawson Formation
    Stratigraphic age (youngest) Paleocene
    Stratigraphic age (youngest) Paleocene
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Conglomerate

Nearby scientific data

(1) -104.75278, 39.39056
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description Denver Basin, Front Range Uplift
Type of structure Local
Structure description Denver Basin

Ore body information

  • General form IRREGULAR

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic
Deposit size Small
Significant No

Mining district

District name Castle Rock Area

Land status

Ownership category Private

Comments on development

  • ONE OF SEVERAL DENVER BASIN DEPOSITS INVESTIGATED BY USBM AND USGS FOR MN POTENTIAL AS RESULT OF STRATEGIC MINERALS ACT AND WW II NEEDS. NO COMMERCIAL QUANTITIES DISCLOSED AT THAT TIME

Reference information

Bibliographic references

  • Deposit

    WELLS, R.R., AND OTHERS, 1952, BENEFICIATION OF OXIDE MANGANESE ORES FROM ARAPAHOE, DOUGLAS, SAGUACHE, CUSTER, CHAFFEE, AND PARK COUNTIES, COLORADO: USBM RI-4845, P. 3-6.

  • Deposit

    TRIMBLE, D.E., AND MACHETTE, M.N., 1979, GEOLOGIC MAP OF THE GREATER DENVER AREA, FRONT RANGE URBAN CORRIDOR, COLORADO: USGS MAP I-856-H

  • Deposit

    TRAVER, W.M., JR., 1947, INVESTIGATIONS OF STRATEGIC MINERAL RESOURCES, IN VANDERWILT, J.W., MINERAL RESOURCES OF COLORADO: COLORADO STATE MINERAL RESOURCES BOARD, P. 490-491.

General comments

Subject category Comment text
Deposit MN OXIDES OCCUR AS IRREGULAR MASSES 20 TO 200 MESH IN SIZE FILLING INTERSTICES OF ARKOSIC SANDSTONE IN DAWSON FM
Deposit DENVER BASIN MN OCCURRENCES WERE CONSIDERED TOO LOW GRADE FOR COMMERCIAL FERROMANGANESE MANUFACTURE BUT USBM ORE-DRESSING TESTS INDICATED SOME DEGREE OF CONCENTRATION POSSIBLE BY SIZING METHODS AND BY SIMPLE TABLING AND SINTERING. FLOTATION INCREASED MN RECOVERY BUT LOWERED GRADE DUE TO EXCESS SILICA AND BARIUM ; INFO.SRC : 1 PUB LIT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-AUG-82 Schwochow, Stephen D. Colorado Geological Survey

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.