Mount Si

Occurrence in King county in Washington, United States with commodity Copper
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. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Land status
  15. Ownership information
  16. Links to other databases
  17. Bibliographic references
  18. General comments
  19. Reporter information

Geologic information

Identification information

Deposit ID 10048499
MRDS ID MP00088
Record type Site
Current site name Mount Si
Alternate or previous names Bald Hornet Claims

Geographic coordinates

Geographic coordinates: -121.70621, 47.51342 (WGS84)
Elevation 1292
Relative position ABOUT 1.5 MI EAST OF SUMMIT OF MOUNT SI

Site location context

Political divisions (FIPS codes)

King(county)

Washington(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Mount Si(quadrangle 1:24,000 scale)

Skykomish River(quadrangle 1:100,000 scale)

Wenatchee(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Snoqualmie(hydrologic unit)

Puget Sound(hydrologic accounting unit)

Puget Sound(hydrologic subregion)

Pacific Northwest(hydrologic region)

Geographic areas

Country State County
United States Washington King

Public Land Survey System information

Meridian Township Range Section Fraction State
Willamette 023N}024N 008E}009E 01}31 NE4 (01); S2 (31) Washington

Comments on the location information

  • MINERALIZED AREA IS EAST OF SUMMIT OF MOUNT SI. LOCATION GIVEN IS FOR TOURMALINE BRECCIA

Commodities

Commodity Importance
Copper Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore
Quartz Gangue
Sericite Gangue
Tourmaline Gangue

Alteration

  • (Local) Plutonic Rocks Intensely Sericitized (Phyllic)

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Rock unit name Snoqualmie Batholith
    Rock description Snoqualmie Batholith
    Stratigraphic age (youngest) Miocene
    Stratigraphic age (youngest) Holocene
    Stratigraphic age (youngest) Holocene
    Stratigraphic age (youngest) Miocene
  • Host or associated Host
    Rock type Metamorphic Rock > Hornfels
    Rock unit name Western Melange Belt
    Rock description Western Melange Belt

Nearby scientific data

(1) -121.70621, 47.51342

Economic information

Ore body information

  • General form BRECCIA

Controls for ore emplacement

  • Brecciation Of Country Rock

Comments on the geologic information

  • HORNFELS PROTOLITH MAY HAVE BEEN PRE-TERT QUARTZITE AND SEDIMENTARY ROCKS

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic
Deposit size Small
Significant No
Discoverer Duval Corp

Land status

Ownership category Private

Ownership information

  • Type Operator
    Owner Duval Corp. (1970'S)
  • Type Owner
    Owner Weyerhaeuser Co.
    First year 1991

Comments on the workings information

  • 15 WINKIE HOLES TOTALLING 1,500 FT, SOIL SAMPLING PROGRAM

Reference information

Bibliographic references

  • Deposit

    ASHLEY, R.P., 1991, FIELD EXAM WITH GRANT NEWPORT OF WEYERHAUSER

  • Deposit

    TABOR, R.W., FRIZZELL, V.A., JR., BOOTH, D.B., WHETTEN, J.T., WAITT, R.B., JR., AND ZARTMAN, R.E., 1982, PRELIMINARY GEOLOGIC MAP OF THE SKYKOMISH RIVER 1:100,000 QUADRANGLE, WASHINGTON: U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 82-747, SCALE 1:100,000.

General comments

Subject category Comment text
Deposit DEPOSIT HAS BEEN GIVEN THE INFORMAL NAME OF A BRECCIA PIPE CU DEPOSIT, FOR WHICH THERE IS NO PUBLISHED MODEL. QUARTZ-PYRITE-TOURMALINE VEINLETS. TOURMALINE VEINLETS ARE CUT BY LATER QUARTZ VEINLETS. TOURMALINE BRECCIA LOOKS LIKE COLLAPSE FEATURE IN HORNFELS. THERE ARE SEVERAL BRECCIA BODIES IN AREA

Reporter information

Type Date Name Affiliation Comment
Reporter 01-SEP-1991 Peterson, Jocelyn A. U.S. Geological Survey

Beyond USGS

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