Sweetheart Ridge Gold-Copper-Silver Prospect

Prospect in Alaska, United States with commodities Gold, Copper, Silver, Lead, Zinc
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Host and associated rocks
  8. Nearby scientific data
  9. Geologic structures
  10. Ore body information
  11. Controls for ore emplacement
  12. Economic information about the deposit and operations
  13. Mining district
  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 10002407
MRDS ID A013325
Record type Site
Current site name Sweetheart Ridge Gold-Copper-Silver Prospect
Alternate or previous names Elephant, Mastadon, Readgister, Golden Gate Claims
Related records 10161171, 10185349

Geographic coordinates

Geographic coordinates: -133.62418, 57.92364 (WGS84)
Elevation 875
Relative position 0.65 MI. SW OF PEAK 3405, ON RIDGE BETWEEN TRACY ARM AND SWEETHEART CRK.

Site location context

Political divisions (FIPS codes)

Juneau(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Sumdum D-5(quadrangle 1:63,360 scale)

Sitka NE(quadrangle 1:100,000 scale)

Sumdum(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Central Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Tongass National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Comments on the location information

  • USGS B 1525, FIG. 59, 61, 63, SAMPLE 90. LOCATION IS AT SITE OF SECTION OF BEST MINERALIZATION. MINERALIZED AREA EXTENDS AT LEAST 1,000 FT. N AND S AND 200 FT. E AND W OF LOCATION. LAND STATUS VALUE CALCULATED 6-94 USING GIS OVERLAY ANALYSIS WITH BLM 1:2,500,000 SCALE OWNERSHIP STATUS MAP (1991).

Commodities

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

Comments on the commodity information

  • ANALYTICAL DATA FROM USGS B 1525, P. 175, 286-289, TABLE 26.

Materials information

Materials Type of material
Chalcopyrite Ore
Gold Ore
Sphalerite Ore
Biotite Gangue
Chlorite Gangue
Epidote Gangue
Garnet Gangue
Goethite Gangue
Hornblende Gangue
Muscovite Gangue
Pyrite Gangue
Quartz Gangue

Analytical data

Result CHANNEL, CHIP SAMPLES UP TO 0.577 OZ/TON AU, 2.6% CU, 0.65 OZ/TON AG, 1.8% PB, 1.9% ZN

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss

Nearby scientific data

(1) -133.62418, 57.92364

Economic information

Geologic structures

Type of structure Local
Structure description Nw Striking, Steep Dipping Foliation Of Schist And Gneiss

Ore body information

  • General form POD
    Strike NW
    Dip STEEP
    Length 3048M
    Width 60.96M

Controls for ore emplacement

  • Along Altered Zone

Comments on the geologic information

  • DEPOSIT ALONG 5.5 MI. LONG LINEAR DEPRESSION FROM TRACY ARM TO SWEETHEART LAKE, APPARENTLY CAUSED BY DIFFERENTIAL WEATHERING OF CHLORITE SCHIST, WHICH SEPARATES E AND W PARTS OF DEPOSIT.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic
Deposit size Small
Significant No

Mining district

District name Juneau

Land status

Ownership category National Forest

Ownership information

  • Type Operator
    Owner Mapco
    First year 1982

Comments on the reserve resource information

  • ZONE OF HIGHEST GRADE MINERALIZATION, 147 FT. LONG AND 5.5 FT. WIDE CONTAINS ESTIMATED AVERAGE TONNAGE OF 7,300 TONS PER 100 FT. DEPTH AT AVERAGE GRADE OF 0.23 OZ/TON AU, 0.31 OZ/TON AG, AND 0.7% CU, ACCORDING TO USGS B 1525, P. 173.

Comments on the workings information

  • NUMEROUS SURFACE-SAMPLING TRENCHES CUT BY USBM IN 1975, SEVERAL THOUSAND FT. OF DIAMOND DRILLING HOLES BY MAPCO IN 1978-82.

Comments on development

  • DISCOVERED AND CLAIMS STAKED AS EARLY AS LATE 1890'S. REDISCOVERED BY USBM IN 1974. EXTENSIVE DIAMOND DRILLING, GEOPHYSICAL EXPLORATION BY MAPCO FROM 1978-1982, BUT NO MAJOR WORK SINCE THEN.

Reference information

Bibliographic references

  • Deposit

    USGS B 1525, P. 169-175, TABLE 26, FIGS. 59-63 (1984)

  • Deposit

    USBM OFR 85-86, P. 47-48, FIG. 4, LOC. 161 (1986)

  • Deposit

    USGS OF 78-698, P. 33 (1978)

  • Other Database

    BAG-B-1525-FIG-59, 61, 63

General comments

Subject category Comment text
Deposit FIELD AND PETROGRAPHIC EXAMINATION SUGGEST THAT DEPOSIT IS POSSIBLY OF SEDIMENTARY ORIGIN. IF SO, PERSISTENCE OF METALLIC MINERALIZATION ALONG STRIKE AND DOWN DIP MIGHT BE EXPECTED. ; INFO.SRC : 1 PUB LIT
Deposit THIS SITE NAME WAS CREATED BY THE REPORTER OR OTHER USGS EMPLOYEE BASED ON PROXIMITY TO SOME MAJOR GEOGRAPHIC FEATURE.
Deposit STRATIFORM SULFIDE BODY IN MICA SCHIST BELT WITHIN GREENSCHIST. IRON-STAINED MINERALIZED ZONE IS LAYERED AND GRADES FROM PHYLLITE TO SCHIST TO QUARTZ-RICH GNEISS. SULFIDES ARE DISSEMINATED AND IN THIN LAYERS, CONSISTING LARGELY OF CHALCOPYRITE, PYRITE, OCCASIONAL SPHALERITE, AND RARELY GALENA. DISSEMINATED PYRITE AND CHALCOPYRITE ARE CONCENTRATED IN LAYERS WITHIN ZONE THAT ALIGNS WITH FOLIATION. MINERALIZED ZONE EXTENDS AT LEAST 2000 FT., NW-SE. CHALCOPYRITE STRINGERS FOUND IN ZONE 10,000 FT. LONG BY 200 FT. WIDE. SEVERAL MASSIVE SULFIDE PODS UP TO 8 IN. WIDE AND 6 FT. LONG ARE FOUND IN AREA A FEW HUNDRED FT. LONG. PODS CONTAIN ABUNDANT SPHALERITE, CHALCOPYRITE, PYRITE AND GALENA. MOST IMPORTANT MINERALIZED BAND IS IN WEST-CENTRAL SECTION, CONSISTING OF CATACLASTIC QUARTZ-RICH GNEISS 5-6 FT. THICK WITH STRIKE LENGTH OF 147 FT., CAPPED BY INTENSE ORANGE-RED IRON STAIN.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1987 Leonard, Kenneth R. (Huber, Donald F.) U.S. Geological Survey
Editor 14-SEP-1994 Waller, Nichelle (Mosier, Dan) U.S. Geological Survey PARSED OUT HOST ROCK AND ASSOCIATED ROCK TYPES, AGES, UNIT NAMES, AND UNIT AGES.

Beyond USGS

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

Authoritative Alaska resources

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