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Irelan

Past Producer in Sierra county in California, United States with commodity Gold
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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. Ore body information
  12. Economic information about the deposit and operations
  13. Workings at the site
  14. Links to other databases
  15. Bibliographic references
  16. General comments
  17. Reporter information

Geologic information

Identification information

Deposit ID 10106529
MRDS ID X025385
Record type Site
Current site name Irelan
Related records 10213853, 10237899

Geographic coordinates

Geographic coordinates: -120.82436, 39.44017 (WGS84)
Relative position 1 3/4 MI SSE OF ALLEGHANY

Site location context

Political divisions (FIPS codes)

Sierra(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Alleghany(quadrangle 1:24,000 scale)

Truckee(quadrangle 1:100,000 scale)

Chico(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Yuba(hydrologic unit)

Lower Sacramento(hydrologic accounting unit)

Sacramento(hydrologic subregion)

California(hydrologic region)

Federal lands

Tahoe 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 California Sierra

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 018N 010E 11 California

Commodities

Commodity Importance
Gold Primary

Comments on the commodity information

  • BEST ORE NEAR SURFACE. HIGH GRADE POCKETS SAID TO BE WHERE QTZ IS THICKEST. POSSIBLE CORRELATION OF HIGH-GRADE BUNCHES W STRINGERS BRANCHING FROM WALL ON HANGING WALL SIDE.

Materials information

Materials Type of material
Gold Ore
Quartz Gangue

Alteration

  • (Local) Carbonate

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro
    Stratigraphic age (youngest) Late Permian
  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Slate
  • Host or associated Host
    Rock type Metamorphic Rock > Schist
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Pyroclastic Rock > Tuff

Nearby scientific data

(1) -120.82436, 39.44017
ListMap

Economic information

Ore body information

  • Strike N 60 W
    Dip 50 NE
    Thickness 1.52M

Comments on the geologic information

  • 2 VEINS IN TUFFS, SLATES INTRUDED BY SCHISTOSE GABBRO INTENSE SHEARING & ALTERATION CLOSE TO VEIN. TUFFS & SLATE ARE HANGING WALL OF E VEIN, FOOTWALL OF W VEIN, SUGGESTING REVERSE MOVEMENT ON BOTH VEINS. 2 OTHER SMALLER VEINS IN UPPER WORKINGS. VEIN CHANGES STRIKE SHARPLY FROM N 60 W TO N 30 W FOR 500 - 1000 FT, THEN REVERSE TO ORIGINAL DIRECTION. DIP VARIES 30 - 70 NE, FLATTER AT SURFACE. QTZ LACKING IN PLACES. POST MINERAL MOVEMENT, LITTLE GOUGE, BUT SOME QTZ CEMENTED QTZ BRECCIA INDICATES MOVEMENT PRIOR TO VEIN FILLING. SMALL POSTMINERAL TRANSVERSE FAULT. ARSENOPYRITE WAS CRUSHED BEFORE AU WAS INTRODUCED.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No

Comments on the production information

  • WORKED INTERMITTENTLY.

Workings at the site

  • Type of workings Surface/Underground
    Overall depth 97.54M
    Overall length 304.8M

Comments on the workings information

  • ADITS, 1500 FT APART, WINZES, DRIFTS. SHALLOW SURFACE WORKINGS.

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit VEINS, POCKETS, SHOOTS

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAR-1979 Hayden, F. (Albers, J.) U.S. Geological Survey

Beyond USGS

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

Current status (per MSHA)

StatusAbandoned since 01/09/2013
MSHA mine ID0404319
Mine name (MSHA)Irelan Mine
Current operatorHAROLD MASON LIVING TR DTD 9-25-96 AS AMENDED
Current controller (parent)Daniel Mason
Mine typeUnderground (Metal / non-metal)

Inferred by coordinate + name similarity (950 m, 1.00 match). Confirm against MSHA if precision matters — non-USGS-curated cross-references may occasionally point at a neighbouring mine.

Open MSHA's Mine Data Retrieval System for inspections, accidents, and violations for this mine.

External references

Maps centered on this site

Authoritative California resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.