Last Chance-Shady Tree Mine

Occurrence in Beaverhead county in Montana, United States with commodities Thorium, Uranium
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. Host and associated rocks
  10. Nearby scientific data
  11. Geologic structures
  12. Ore body information
  13. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Mining district
  16. Ownership information
  17. Reserves and resources
  18. Workings at the site
  19. Links to other databases
  20. Bibliographic references
  21. General comments
  22. Reporter information

Geologic information

Identification information

Deposit ID 10096234
MRDS ID W013427
Record type Site
Current site name Last Chance-Shady Tree Mine
Alternate or previous names Staatz Loc. No. 82
Related records 10123468, 10269704

Geographic coordinates

Geographic coordinates: -113.46284, 44.93683 (WGS84)
Elevation 2271
Relative position 2.6 MILES SW OF LEMHI PASS

Site location context

Political divisions (FIPS codes)

Beaverhead(county)

Montana(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Lemhi Pass(quadrangle 1:24,000 scale)

Leadore(quadrangle 1:100,000 scale)

Dubois(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Red Rock(hydrologic unit)

Missouri Headwaters(hydrologic accounting unit)

Missouri Headwaters(hydrologic subregion)

Missouri(hydrologic region)

Federal lands

Beaverhead-Deerlodge National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Montana Beaverhead

Public Land Survey System information

Meridian Township Range Section Fraction State
Montana Principal 010S 015W 29 Montana

Comments on the location information

  • OVER THE DIVIDE BETWEEN NORTH AND SOUTH FRYING PAN CREEK

Commodities

Commodity Importance
Thorium Primary
Uranium Secondary

Materials information

Materials Type of material
Thorite Ore
Barite Gangue
Chalcedony Gangue
Goethite Gangue
Microcline Gangue
Specularite Gangue

Alteration

  • (Local) Silica And Sericite

Analytical data

Result TH AVERAGES .6

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Argillite
    Rock unit name Belt Series, Metamorphosed Sediments
    Rock description Belt Series, Metamorphosed Sediments

Nearby scientific data

(1) -113.46284, 44.93683

Economic information

Geologic structures

Type of structure Regional
Structure description Folding And Faulting Locally
Type of structure Local
Structure description In The District, Veins Are E-W Trending Tension Fractures And Nw Trending Shear Fractures

Ore body information

  • Strike N 65 W
    Dip 60 SW
    Thickness 9.14M
    Length 1188.72M
    Width 7M

Controls for ore emplacement

  • E-W Trending Vein Parallel To Dan Patch - Fault

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic
Deposit size Large
Significant No
Discovery year 1947
Discoverer R. A. Wellborn

Mining district

District name Lemhi Pass District

Ownership information

  • Type Owner
    Owner Sawyer - Adecor Inter.
    Home office 3780 Wilshire Blvd., Los Angeles, Calif. 90010

Reserves and resources

  • Type In-situ
    Estimate year 1972
    Commodity Subtype Grade units Group Importance Year
    Thorium Th 0.669 wt-pct Thorium Major 1972

Comments on the reserve resource information

  • CUTOFF GRADE OF 0.25 % THORIA OVER A LENGTH OF 2000 FT AND A PROJECTED DEPTH OF 250 FT.

Workings at the site

  • Type of workings Underground
    Length 243.84M
    Overall depth 45.72M

Comments on the workings information

  • TWO ADITS, 80 FT SHAFT AND NUMEROUS BULL DOZER CUTS AND TRENCHES

Reference information

Bibliographic references

  • Analytical Data

    SRC.REF: GEACH R. D., 1972

  • Deposit

    GEACH, 1972, MINES & MINERAL DEPOSITS - BEAVERHEAD CO., MT. BUREAU MINES & GEOLOGY BULL. 85.

  • Deposit

    LAWSON, 1974, DIRECTORY OF MINING ENTERPRISES FOR 1974, MT. BUREAU MINES & GEOLOGY BULL. 95.

  • Deposit

    1953 GEOLMAP TRITES A. F., TOOKER E. W., BULL. 988-H

  • Deposit

    1962 GEOLMAP SHARP W. M., CAVENDER W. S., BULL 1126

  • Deposit

    1972 GEOLMAP STAATZ M. H., BULL 1351

General comments

Subject category Comment text
Deposit Discovery Year: LATE 1940'S

Reporter information

Type Date Name Affiliation Comment
Reporter 01-APR-1976 Mlynarczyk, Meg S.; Krohn, D. U.S. Geological Survey
Updater 01-DEC-1979 Doyle, Brien (Wells, John) U.S. Geological Survey

Beyond USGS

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