Earl Lode

Past Producer in Custer county in South Dakota, United States with commodities Feldspar, Mica, Beryllium, Lithium
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. Ore body information
  12. Economic information about the deposit and operations
  13. Mining district
  14. Land status
  15. Ownership information
  16. Workings at the site
  17. Links to other databases
  18. Bibliographic references
  19. General comments
  20. Reporter information

Geologic information

Identification information

Deposit ID 10055682
MRDS ID SD02296
Record type Site
Current site name Earl Lode

Geographic coordinates

Geographic coordinates: -103.52806, 43.75246 (WGS84)
Elevation 1631
Relative position 1.25 MILES SOUTH OF STOCKADE LAKE AND ABOUT 4 MILES EAST-SOUTHEAST OF CUSTER, SOUTH DAKOTA. TAKE U.S. 16 EAST FROM CUSTER, 3.1 MILES FROM WHERE IT LEAVES U.S. 85A, (1940'S HIGHWAY NUMBER) TO THE FRENCH CREEK ROAD. HERE TURN SOUTH FOR 1.1 MILES TO WHERE THE ROAD FIRST COMES ALONGSIDE FRENCH CREEK. FROM THIS POINT A SIDE ROAD LEADS WEST UP THE SMALL VALLEY (BETWEEN THE TWO RIDGES RUNNING EAST FROM MT. ERIN) TO THE MINE, A DISTANCE OF ABOUT A HALF-MILE. THE MINE IS AT AN ELEVATION OF ABOUT 5350 FEET, SOME 300 FEET VERTICALLY ABOVE THE ROAD.

Site location context

Political divisions (FIPS codes)

Custer(county)

South Dakota(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Custer(quadrangle 1:24,000 scale)

Mount Rushmore(quadrangle 1:100,000 scale)

Hot Springs(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Middle Cheyenne-Spring(hydrologic unit)

Cheyenne(hydrologic accounting unit)

Cheyenne(hydrologic subregion)

Missouri(hydrologic region)

Federal lands

Black Hills 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 South Dakota Custer

Public Land Survey System information

Meridian Township Range Section Fraction State
Black Hills 003S 005E 33 South Dakota

Comments on the location information

  • NW 1/4, NW 1/4, NE 1/4

Commodities

Commodity Importance
Feldspar Primary
Mica Primary
Beryllium Critical Primary
Lithium Critical Tertiary

Materials information

Materials Type of material
Albite Ore
Beryl Ore
Lithiophilite Ore
Muscovite Ore
Cleavelandite Gangue
Microcline Gangue
Quartz Gangue
Tourmaline Gangue
Triphylite Gangue

Alteration

  • (Local) Albitization Has Been Prevasive

Analytical data

Result ROCK CONTAINS 10 TO 20 PERCENT MICA.

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Pegmatite
    Rock unit name Pegmatite
    Rock description Pegmatite
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone
    Rock unit name Quartz Sandstone And Graywacke
    Rock description Quartz Sandstone And Graywacke

Nearby scientific data

(1) -103.52806, 43.75246

Economic information

Ore body information

  • General form DIKE
    Strike N 75 E
    Dip 55 NW
    Thickness 7.62M
    Length 60.96M
    Width 7.62M

Economic information about the deposit and operations

Development status Past Producer
Commodity type Both
Deposit size Small
Significant No
Year of first production 1937

Mining district

District name Custer District

Land status

Ownership category National Forest
Area name Black Hills National Forest

Ownership information

  • Type Owner
    Owner Langford Landis And Delbert Mckenna

Workings at the site

  • Type of workings Surface/Underground
    Overall depth 28.65M
    Overall length 51.82M
    Overall width 15.24M

Comments on the workings information

  • PIT IS 50 FEET DEEP.

Reference information

Bibliographic references

  • Deposit

    U.S. BUREAU OF MINES, 1954, BLACK HILLS MINERAL ATLAS, SOUTH DAKOTA: PART 1, BUREAU OF MINES INFORMATION CIRCULAR 7688

  • Deposit

    FISHER, D.J., 1945, PRELIMINARY REPORT ON THE MINERALOGY OF SOME PEGMATITES NEAR CUSTER, SOUTH DAKOTA GEOLOGICAL SURVEY REPORT OF INVESTIGATIONS 50

  • Production

    U.S. BUREAU OF MINES, 1955, BLACK HILLS MINERAL ATLAS, SOUTH DAKOTA: PART 2, BUREAU OF MINES INFORMATION CIRCULAR 7707

General comments

Subject category Comment text
Deposit AT LEAST 3 ZONES - MOST MICA IS IN THE WALL ZONE. BERYL IS FOUND IN THE WALL AND INTERMEDIATE ZONE. MUSCOVITE BOOKS UP TO 30 INCHES HAVE BEEN MINED. MICA IS RULED, AIR STAINED, SOFT AND FRIABLE.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-AUG-1980 Barari, Rachel A. U.S. Geological Survey

Beyond USGS

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

External references