Bronco Mine

Past Producer in Custer county in Idaho, United States with commodities Gold, Silver, Lead, Copper, Zinc

Geologic information

Identification information

Deposit ID 10070988
MRDS ID W014154
MAS/MILS ID 0160370373
Record type Site
Current site name Bronco Mine
Alternate or previous names Apex, Golden Nugget, Mountain Girl

Geographic coordinates

Geographic coordinates: -114.95594, 44.25128 (WGS84)
Elevation 1981
Relative position 3.5 MI NW OF LOWER STANLEY
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Geographic areas

Country State County
United States Idaho Custer

Public Land Survey System information

Meridian Township Range Section Fraction State
Boise 011N 013E 29 SESE Idaho

Comments on the location information

  • THE MINE IS NEAR THE TOP OF THE LOW RIDGE SW OF STANLEY CREEK LAND STATUS VALUE CALCULATED 7-94 USING GIS OVERLAY ANALYSIS WITH USFS LAND OWNERSHIP BOUNDARIES, 1:126,720 SCALE.

Commodities

Commodity Importance
Gold Primary
Silver Primary
Lead Primary
Copper Secondary
Zinc Tertiary

Materials information

Materials Type of material
Chalcopyrite Ore
Chrysocolla Ore
Malachite Ore
Limonite Gangue
Quartz Gangue

Alteration

  • (Local) Oxidation

Analytical data

Result 2 CHIP SAMPLES OXIDIZED PART OF VEIN ASSAYED AT 0.42 OZ AU AND 2.46 OZ AG PER TON
Result 5 CHIP SAMPLES TAKEN FROM VEIN EXPOSURES CONTAINED TRACE AU AND AG, 5.5% PB, 0.9% ZN, 0.09% CU. 19 SELECT DUMP SAMPLES CONTAINED FROM 0.01 - 0.35 OZ AU/TON, 0.01 - 2.63 OZ AG/TON, 0.02 - 5.50% PB, 0.003 - 0.06% ZN, TRACE - 0.41% CU.

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite
    Rock unit name Idaho Batholith-Quartz Monzonite
    Rock description Idaho Batholith-Quartz Monzonite
    Stratigraphic age (youngest) Late Cretaceous
    Stratigraphic age (youngest) Late Cretaceous
    Stratigraphic age (youngest) Late Cretaceous
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite

Nearby scientific data

(1) -114.95594, 44.25128

Geologic structures

Type Description Terms
Regional Idaho Batholith
Local Fault Zone, Brecciation

Ore body information

  • General form LINEAR, STRINGERS
    Strike N 30 DEG E
    Dip 40 DEG SE
    Thickness 0.91M
    Length 640.08M

Controls for ore emplacement

  • Fault Zone

Economic information

Economic information about the deposit and operations

Operation type Underground
Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1895
Discoverer Patrick Lynch
Discovery method Ore-Mineral In Place

Mining district

District name Valley Creek District

Land status

Ownership category National Forest
Area name Challis National Forest

Ownership information

  • Type Owner-Operator
    Owner Fred And Earl Shirts

Workings at the site

  • Type of workings Surface/Underground
    Length 68.58M

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS W014154
Idaho Geological Survey Idaho Mines and Prospects IMP CH_476 http://www.idahogeology.org/
U.S. Bureau of Mines Minerals Availability System MAS 0160370373 data consolidated into this record

Bibliographic references

  • Deposit

    CHOATE, RAOUL, 1962, GEOLOGY AND ORE DEPOSITS OF THE STANLEY AREA: IDAHO BUREAU OF MINES AND GEOLOGY PAMPHLET 126, 120 P.

  • Deposit

    TSCHANZ, C. M., AND OTHERS, 1974, MINERAL RESOURCES OF THE EASTERN PART OF THE SAWTOOTH NATIONAL RECREATION AREA, CUSTER AND BLAINE COUNTIES, IDAHO: USGS OPEN - FILE REPT., 648 P.

  • Deposit

    1962 GEOLMAP IDAHO BUREAU OF MINES AND GEOLOGY PAMPHLET 126

  • Deposit

    1974 RECON TSCHANZ, C. M., AND OTHERS, OPEN - FILE REPT.

  • Production

    TSCHANZ, C. M., AND OTHERS, 1974, USGS O. F. REPT., P. 484

  • Deposit

    VANNOY & OTHERS, 1986, USGS BULL.1545E, P.387, PL.3, NO.25

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JAN-1975 Yett, Jay R.; Miller, Pat U.S. Geological Survey
Reporter 30-JUN-1992 McHugh, Edward L. U.S. Bureau of Mines