Earl Lode

The Earl Lode is a feldspar, mica, and beryllium mine located in Custer county, South Dakota at an elevation of 5,351 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Earl Lode

Commodity

Primary: Feldspar
Primary: Mica
Primary: Beryllium
Tertiary: Lithium

Location

State: South Dakota
County: Custer
District: Custer District

Land Status

Land ownership: National Forest
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.
Administrative Organization: Black Hills National Forest

Holdings

Not available

Workings

Type: Surface/Underground

Ownership

Owner Name: Langford Landis And Delbert Mckenna

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1937
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Interior Plains
Physiographic Province: Great Plains Province
Physiographic Section: Black Hills

Mineral Deposit Model

Not available

Orebody

Form: DIKE

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Albitization Has Been Prevasive

Rocks

Name: Pegmatite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Neoproterozoic

Name: Pegmatite
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic

Name: Pegmatite
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic

Name: Pegmatite
Role: Associated
Age Type: Host Rock Unit
Age Young: Neoproterozoic

Analytical Data

Analytical Data: ROCK CONTAINS 10 TO 20 PERCENT MICA.

Materials

Ore: Albite
Ore: Muscovite
Ore: Beryl
Ore: Lithiophilite
Gangue: Microcline
Gangue: Quartz
Gangue: Triphylite
Gangue: Tourmaline
Gangue: Cleavelandite

Comments

Comment (Location): NW 1/4, NW 1/4, NE 1/4

Comment (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.

Comment (Workings): PIT IS 50 FEET DEEP.

References

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

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

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

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