Duncan

  

Mine Info

State: California

County: Mariposa

Elevation: 925 feet (282 meters)

Primary Mineral: Gold

Lat, Long: 37.49083, -120.21583



Duncan MRDS details

Site Name

Commodity

Location

Primary: "Duncan"
Secondary: "Lost Douglas"
Primary: Gold
Secondary: Silver
State: California
County: Mariposa
District:
 

Land Status

Holdings

Workings

Land ownership:
Administrative Organization:
Type: Surface/Underground


Ownership

Production

Deposit

Owner Name: George D. Turner
Company ID:
Percent:
Home Office:
Info Year:
Years: -

Year: 1935
Time Period: - 1935
Mined:
Material type: ORE
Description: Cp_Grade: ^.08 Oz/Ton Au .04 Oz/Ton Ag
Year: 1927
Time Period:
Mined:
Material type: AU
Description: Ap_Grade: ^ .14 Oz/Ton Ag
Year: 1927
Time Period:
Mined:
Material type: ORE
Description: Ap_Grade: ^.45 Oz/Ton Au
Record Type: Site
Operation Category: Past Producer
Deposit Type:
Plant Type:
Plant Subtype:
Operation Type: Unknown
Mining Method:
Milling Method:
Year First Production:
Year Last Production:
Discovery Year: 1870
Discovery Method:
Years of Production:
Organization:
Significant: N
Deposit Size: S


Physiography

Mineral Deposit Model

Orebody

General Physiographic Area: Pacific Mountain System
Physiographic Province: Pacific Border Province
Physiographic Section: California Trough
Physiographic Detail:
Name:
Form: PINCH & SWELL


Structure

Alterations

Rocks

Name: Hornfels
Role: Host
Description:
Age Type: Host Rock
Age in Years:
Dating Method:
Material Analyzed:
Age Young: Late Jurassic
Age Old:


Analytical Data

Materials

Ore: Gold
Ore: Silver
Ore: Pyrite


Comments

Comment Type:
Commodity
Comment LAST ORE MILLED WAS OF MARGINAL GRADE.
Comment Type:
Location
Comment SHORT DISTANCE W OF COMMON 1/4 COR. ON MT. BULLIAN R
Comment Type:
Production
Comment PRODUCTION RECORDS INCOMPLETE. IN 1897- 98, 246 OZ. OF GOLD RECOVERED FROM UNKNOWN QUANTITY OF ORE; IN 1927, 500 TONS OF ORE YIELDED 219.82 OZ. GOLD AND 70 OZ. SILVER. FROM 1932-1935, 1146 TONS OF ORE YIELDED 90 OZ. GOLD AND 45 OZ. SILVER. IDLE SINCE LATE 1930'S AND NO EQUIPMENT ON PROPERTY.
Comment Type:
Deposit
Comment VEIN, POCKETS, ORE SHOOTS
Comment Type:
Workings
Comment SERIES OF OPEN PITS AND CAVED SHAFTS STRUNG OUT ALONG THE VEIN FOR NEARLY 1/2 MILE. MAIN SHAFT 325' IN 1935.
Comment Type:
Geology
Comment GEOL.DESC: VEIN MEASURED AT SURFACE, 2 - 5 FT. ACROSS. WALL ROCKS ARE SCHISTOSE GREENSTONE, QUARTZ BIOTITE SCHIST AND QUARTZ BIOTITE HORNFELS.
Comment Type:
Deposit
Comment ONE PATENTED CLAIM. MINE IS NOTED FOR ITS POCKETY CHARACTER.


References

Reference Category:
Deposit
Pages:
Reference: BOWEN, O. E., JR., & GRAY, H., JR., 1957 , MINES AND MINERAL DEPOSITS OF MARIPOSA COUNTY, CALIF.: CALIF. JOUR. MINES & GEOL., VOL. 53 , NOS. 1 & 2 , P. 96 , 256 .
URL:
Reference Category:
Deposit
Pages:
Reference: LAIZURE, C. MCK., 1928 , S. F. FIELD DIV. - MARIPOSA COUNTY: 24TH REPORT STATE MINERALOGIST, VOL. 24 , NO. 2 , P. 85 .
URL:
Reference Category:
Production
Pages:
Reference: BOWEN AND GRAY, 1957
URL:

Did You Know.......

A mine is a hole in the ground, owned by a liar.
-Mark Twain

About The MRDS Mines Database

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.

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