The Grand Island Group is a gold and silver mine located in Pennington county, South Dakota at an elevation of 4,600 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
Elevation: 4,600 Feet (1,402 Meters)
Commodity: Gold, Silver
Lat, Long: 43.90528, -103.42917
Map: View on Google Maps
Grand Island Group MRDS details
Site Name
Primary: Grand Island Group
Commodity
Primary: Gold
Primary: Silver
Location
State: South Dakota
County: Pennington
District: Keystone 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: Underground
Ownership
Not available
Production
Not available
Deposit
Record Type: Site
Operation Category: Occurrence
Deposit Type: Vein
Operation Type: Unknown
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
Not available
Structure
Not available
Alterations
Not available
Rocks
Name: Diorite
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic
Name: Diorite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Neoproterozoic
Analytical Data
Not available
Materials
Ore: Silver
Ore: Pyrite
Ore: Pyrrhotite
Ore: Gold
Gangue: Quartz
Comments
Comment (Location): ADJACENT TO AND SOUTH OF THE EGYPTIAN GROUP
Comment (Development): ECON.COM: ORE IS LOW GRADE
Comment (Deposit): SAME MINERALIZED SHEAR ZONE AS THE KEYSTONE & BULLION PROPERTIES.
References
Reference (Deposit): U.S. BUREAU OF MINES, 1955, BLACK HILLS MINERAL ATLAS, SOUTH DAKOTA: PART 2, BUREAU OF MINES INFORMATION CIRCULAR 7707
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