Gold Bluff Prospect

Prospect in Marquette county in Michigan, United States with commodity Gold
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. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Ownership information
  16. Bibliographic references
  17. General comments
  18. Reporter information

Geologic information

Identification information

Deposit ID 10310193
MRDS ID LW00193
Record type Site
Current site name Gold Bluff Prospect

Geographic coordinates

Geographic coordinates: -87.68058, 46.60972 (WGS84)
Relative position NORTHWEST OF MARQUETTE, MI: ON NORTH SIDE OF DEAD RIVER STORAGE.

Site location context

Political divisions (FIPS codes)

Marquette(county)

Michigan(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Negaunee SW(quadrangle 1:24,000 scale)

Marquette(quadrangle 1:100,000 scale)

Marquette(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Dead-Kelsey(hydrologic unit)

Southcentral Lake Superior(hydrologic accounting unit)

Southern Lake Superior(hydrologic subregion)

Great Lakes(hydrologic region)

Geographic areas

Country State County
United States Michigan Marquette

Public Land Survey System information

Meridian Township Range Section Fraction State
Michigan T49N R28W 28 Michigan

Commodities

Commodity Importance
Gold Primary

Comments on the commodity information

  • QUARTZ, GOLD, PYRITE AND AG & BI TELLURIDES PRESENT IN METABASALTS OF THE LIGHTHOUSE POINT BASALT FORMATION. MINERALIZATION FOUND IN THIN DUCTILE SHEAR ZONES OR CLOSE TO CONTACTS WITH RHYODACITE PORPHYRY. HIGHER GRADE MINERALIZATION ALONG GABBRO/FELSIC CONTACT. GOLD-BEARING VEINS ARE DARK GRAY COMPARED TO BARREN WHITE QUARTZ-CARBONATE-TOURMALINE VEINS.

Materials information

Materials Type of material
Gold Ore
Quartz Gangue
Tourmaline Gangue
Ankerite Gangue
Pyrite Gangue

Alteration

  • (Local) Carbonization

Host and associated rocks

  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Mafic Volcanic Rock > Basalt
    Rock unit name Lighthouse Point Basalt
    Rock description Lighthouse Point Basalt
    Stratigraphic age (youngest) Archean

Nearby scientific data

(1) -87.68058, 46.60972

Economic information

Geologic structures

Type of structure Local
Structure description Dead River shear zone

Controls for ore emplacement

  • Shear zone

Comments on the geologic information

  • THREE LITHOLOGIES FOUND AT GOLD BLUFF: 1) FINE-GRAINED METABASALT; 2) MEDIUM-GRAINED METAGABBRO, AND 3) FELSIC PORPHYRY. MAFIC UNITS ARE METAMORPHOSED TO GREENSHIST FACIES AND CAN BE MASSIVE TO STRONGLY FOLIATED. FELSIC PORPHYRY IS AN INTRUSIVE RHYODACITE. THE ORIENTATION OF BRITTLE AND DUCTILE SHEARS STRUCTURES, FELSIC PORPHYRIES, AND QUARTZ VEINS IS GEOMETRICALLY CONSISTENT WITH A SYSTEM OF CONJUGATE SHEARS THAT CONTROL GOLD MINERALIZATION (BORNHORST ET AL., 1999).

Economic information about the deposit and operations

Operation type Underground
Development status Prospect
Commodity type Metallic
Significant No

Mining district

District name Ishpeming Greenstone District

Ownership information

  • Type Owner
    Owner Callahan Mining Corporation

Comments on the workings information

  • TRENCHING AND DRILLING INTERSECTED SIGNIFICANT WIDTH OF DISSEMINATED LOW GRADE GOLD MINERALIZATION AND HIGHER GRADE GOLD IN MAFIC HOST ROCK.

Comments on development

  • RECENT DRILLING INTERSECTED MINERALIZATION: 224 FT@ 0.18 OPT AU, INCLUDING 11 FT @ 0.178 OPT AND 3' @ 0.122 OPT. MINERALIZATION IN SHEARED GABBRO: 8.7 FT @ 0.188 OPT AU, AND 17 FT @ 0.077 OPT INCLUDING 7.5 FT @ 0.148 OPT WITH VG.

Reference information

Bibliographic references

  • Deposit

    BORNHORST, T.J., DUSKIN, D.J., JOHNSON, R.C., MAHIN, R.A., QUIGLEY, T.O., AND SCOTT, G.W., 1999, ARCHEAN ISPHEMING GREENSTONE BELT AND GOLD MINERALIZATION, MICHIGAN: INSTITUTE ON LAKE SUPERIOR GEOLOGY PROCEEDINGS, 45TH ANNUAL MEETING, MARQUETTE, MI, V. 45 PART 2, P. 12 - 107.

General comments

Subject category Comment text
Deposit OUTCROP SAMPLING YEILDS 1 PPM TO 10 PPM GOLD.
Deposit LOCATED WITHIN A 300 DEGREE TRENDING, 1000 FOOT WIDE SHEAR ZONE IN MAFIC VOLCANICS. A 100-200 FOOT WIDE FELSIC PORPHYRY INTRUDES THE SHEAR ZONE. MINERALIZED SUBSIDIARY EAST-WEST AND NORTHEAST SHEAR ZONES OCCUR WITHIN THE BOUNDING SHEAR ZONE.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-SEP-2002 Anderson, Arlene (M. Gere) Michigan Department of Natural Resources

Beyond USGS

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