Porphyry Dike Mine

Past Producer in Lewis and Clark county in Montana, United States with commodities Gold, Arsenic
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. Geologic structures
  12. Ore body information
  13. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Mining district
  16. Land status
  17. Workings at the site
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10078284
MRDS ID W026542
Record type Site
Current site name Porphyry Dike Mine
Related records 10124757

Geographic coordinates

Geographic coordinates: -112.28839, 46.42768 (WGS84)
Elevation 2280
Relative position 1.5 KM NE OF PAUPER MTN.

Site location context

Political divisions (FIPS codes)

Lewis and Clark(county)

Montana(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Three Brothers(quadrangle 1:24,000 scale)

Butte North(quadrangle 1:100,000 scale)

Butte(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Missouri(hydrologic unit)

Upper Missouri(hydrologic accounting unit)

Missouri-Marias(hydrologic subregion)

Missouri(hydrologic region)

Federal lands

Helena-Lewis and Clark 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 Montana Lewis and Clark

Public Land Survey System information

Meridian Township Range Section Fraction State
Montana Principal 008N 006W 24 NE OF SE Montana

Comments on the location information

  • NEAR HEAD OF MONITOR CREEK. ; INFO FROM LAND.ST :(1954)

Commodities

Commodity Importance
Gold Primary
Arsenic Critical Tertiary

Comments on the commodity information

  • LIMONITE STAINED FRACTURES SAID TO BE PARTICULARLY FAVORABLE PLACES FOR GOLD OCCURRENCE

Materials information

Materials Type of material
Gold Ore
Limonite Gangue
Pyrite Gangue

Alteration

  • (Local) Sericitization, Kaolinization

Host and associated rocks

  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene

Nearby scientific data

(1) Granitic rock

Economic information

Geologic structures

Type of structure Regional
Structure description Large Scale Volcanic And Igneous Intrusive Activities Boulder Batholith
Type of structure Local
Structure description Jointing, Overlapping Of Pyroclastics And Flow Units Thin Dikes And Faults

Ore body information

  • General form IRREGULAR

Controls for ore emplacement

  • Sheeted Zone.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1890
Year of first production 1892

Mining district

District name Rimini District

Land status

Ownership category National Forest

Comments on the production information

  • USGS BULL 1151, P. 115.

Workings at the site

  • Type of workings Surface/Underground
    Area 0.405HA
    Length 731.52M
    Overall depth 38.1M
    Overall length 91.44M
    Overall width 45.72M

Comments on the workings information

  • TWO 1200 FT ADITS UNDER THE PIT, BOTH WITH NUMEROUS CROSSCUTS AND CONNETING VERTICAL WORKINGS. OPEN PIT IS 150 FT WIDE, 300 FT LONG AND 150 FT DEEP.

Comments on development

  • REFERENCE MATERIAL INDICATES THAT THE ANACONDA CO. HAS THOROUGHLY SAMPLED THIS DEPOSIT BY DRILLING

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit 4 INTERLAYERED AND OVERLAPPING PYROCLASTIC AND FLOW UNITS IN THE RHYOLITE. THESE UNITS ARE CUT BY THIN DIKES AND BY FAULTS. PRIMARY GOLD WAS DISSEMINATED IN THE CLOSELY HOINTED, LAMINATED FLOW ROCKS. PART OF FREE GOLD HAS BEEN WASHED INTO OPEN JOINTS AND DESCENDED THROUGH THE RHYOLITE AND CONCENTRATED. RICHEST ORE WAS FROM A VERTICAL SHEETED ZONE.
Deposit THE RICHEST ORE MINED AT THE PORPHYRY DIKE MINE WAS REMOVED FROM A VERTICALLY SHEETED ZONE OF THOROUGH AND DEEP OXIDATION ALONG WHICH CONCENTRATION OF GOLD IN OPEN JOINTS COULD EASILY OCCUR

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAY-1977 Mc Kenzie, Craig L.; R. B. Berg U.S. Geological Survey
Updater 01-DEC-1981 Wise, Kristine K. (Elliott, James E.) U.S. Geological Survey

Beyond USGS

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

External references