Kensington Mine

Producer in Alaska, United States with commodities Gold, Copper, Lead, Silver

Geologic information

Identification information

Deposit ID 10001361
MRDS ID A012101
Record type Site
Current site name Kensington Mine
Related records 10209864

Geographic coordinates

Geographic coordinates: -135.08873, 58.86586 (WGS84)
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Geographic areas

Country State
United States Alaska

Comments on the location information

  • LOCATION IS PRINTED ON JUNEAU D-4 QUAD., 1: 63360 TOPOGRAPHIC SERIES; PROBABLY THE PORTAL OF THE KENSINGTON ADIT; ORE BODY LIES TO THE E. 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 Tertiary
Lead Tertiary
Silver Tertiary

Comments on the commodity information

  • MODE OF OCURRENCE OF AU UNKNOWN; AU RECOVERY ONLY 5% BY AMALGANATION; PYRITE ID DOMINANT SULFIDE

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Albite Gangue
Quartz Gangue

Alteration

  • (Local) Alteration Minerals In Diorite: Chlorite, Epidote, Sericite, Locally K-Spar

Analytical data

Result 0.208-0.29 OZ/TON AU FOR ASSAY BOUNDED AREAS OF 50-300 FT BY 75 TO 150 FT
Result METZ AND WIEBMER, 1977 UNPUB. REPORT

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Rock unit name Jualin Diorite
    Rock description Jualin Diorite
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene
  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite

Nearby scientific data

(1) -135.08873, 58.86586

Ore body information

  • General form OTHER: ELLIPTICAL
    Strike N
    Dip 67 E
    Depth to bottom 304.8M
    Width 24.38M
    Length 48.77M

Comments on the geologic information

  • SEE JUALIN MINE GEOLOGY COMMENTS

Economic information

Economic information about the deposit and operations

Development status Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1891
Year of first production 1897
Year of last production 1904

Mining district

District name Juneau/Berner'S Bay

Land status

Ownership category National Forest

Comments on the production information

  • 12000 TONS MINED BEFORE 1901; AU RECOVERY WAS ONLY 5% BY AMALGAMATION, 62% BY GRAVITY CONCENTRATION, 33% LOST IN TAILINGS

Comments on the reserve resource information

  • METZ AND WIEBMER, 1977 UNPUB. REPORT

Workings at the site

  • Type of workings Surface/Underground
    Length 1524M
    Overall depth 243.84M

Comments on the workings information

  • 5000 FT KENSINGTON ADIT CONNECTIS WORKINGS OF THE KENSINGTON, JOHNSON, EUREKA AND NORTHERN BELLE VEINS; THE KENSINGTON ORE BODY WAS INTERSECTED 1950 FT FROM THE PORTAL, 800 FT BELOW SURFACE, AND WAS EXPLORED BY 640 FT OF DRIFTS IN 1904; MINED FROM SURFACE AND SHALLOW WORKINGS; ADIT IS OPEN

Comments on development

  • MINING 1897-1904; KENSINGTON ADIT EXTENDED TO UNDERCUT HEARBY ORE BODIES IN 1904, AND 1911-1916; KENSINGTON, BEAR AND COMET CONSOLIDATED IN 1915; SEVERAL UNSUCCESSFUL ATTEMPTS TO REOPEN MINE BEFORE WWII; RECENT ACTIVITY: DRILLED IN 1984 BY PLACID OIL CO., TOTAL OF 5,400 FT IN 15 SURFACE HOLES; PLUS SOME ROCK AND GEOCHEMICAL SAMPLING

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A012101

Bibliographic references

  • Deposit

    USGS BULL 287, P. 137

  • Deposit

    USGS BULL 284, P. 32-33

  • Deposit

    USGS BULL 446, P. 40-42

  • Deposit

    USGS BULL 592, P. 59

  • Deposit

    USGS BULL 1246, P. 159-160

  • Deposit

    ADGGS SR 38, P. 14

  • Deposit

    METZ, PAUL A. AND WIEBMER, JOHN D., 1977, M.I.R.L. SUMMARY FILE REPORT; EUREKA, KENSINGTON, COMET, JOHNSON AND JUALIN MINES, BERNER'S BAY JUNEAU DISTRICT, ALASKA: UNPUBLISHED MINING FEASIBILITY STUDY SUBMITTED TO U.S.B.M.

  • Deposit

    USGS OFR85-717, NO. J093

  • Other Database

    BAG-OFR-85-717-093

General comments

Subject category Comment text
Deposit STOCKWORK OF IRREGULAR 1 IN-1 FT QUARTZ VEINS IN HIGH ANGLE ZONES OF SHEARED AND CHLORITIZED DIORITE; ORE BODY IS ELLIPTICAL IN PLAN VIEW, 80 BY 160 FT WITH LONG AXIS TRENDING N-S; VERTICAL EXTENT OVER 1000 FT; SULFIDES: DOMINANTLY PYRITE, SOME CHALCOPYRITE AND RARE GALENA; PYRITE VARIES FROM DISSEMINATED EUHEDRAL CRYSTALS TO MASSIVE VEINS UP TO 1 FT WIDE
Deposit SEE ALSO: JOHNSON, EUREKA, COMET, JUALIN ; INFO.SRC : 1 PUB LIT; 2 UNPUB REPT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-1985 Leonard, Kenneth R. (Elliott, R. L.) U.S. Geological Survey