Midas Mine

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

Geologic information

Identification information

Deposit ID 10000828
MRDS ID A011481
Record type Site
Current site name Midas Mine
Alternate or previous names Granby Consolidated Mining, Smelting and Power Co., Orebodies: Jumbo Lode, All-American
Related records 10136827

Geographic coordinates

Geographic coordinates: -146.27671, 61.01238 (WGS84)
Relative position 7.5 MI S OF OLD VALDEZ
(click for info)

Geographic areas

Country State
United States Alaska

Public Land Survey System information

Meridian Township Range Section Fraction State
010S 006W 10 SW Alaska

Comments on the location information

  • LOCATION GIVEN ON VALDEZ A-7 QUADRANGLE AS MIDAS MINE IS JUMBO LODE, COORDINATES GIVEN ABOVE; THE ALL AMERICAN LODE IS PLOTTED AS A MINE SHAFT SYMBOL ABOUT 1/2 MI SE OF MIDAS ADIT SYMBOL LAND STATUS VALUE CALCULATED 6-94 USING GIS OVERLAY ANALYSIS WITH BLM 1:2,500,000 SCALE OWNERSHIP STATUS MAP (1991). ; INFO FROM LAND.ST :49?

Commodities

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

Comments on the commodity information

  • THE MASSIVE SULFIDE ORE COMMONLY RUNS 3.0 TO 3.5% CU, VARIABLE ZN AND AG, AND LOW TO MODERATE AU; ADGGS GR15

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Pyrrhotite Ore
Sphalerite Ore
Calcite Gangue
Quartz Gangue
Pyrite Unknown

Analytical data

Result 3.4% CU, 4.2% ZN, LESS THAN 0.1% PB, 0.15 OZ/TON AU, 1.46 OZ/TON AG, CHIP SAMPLE ACROSS 3 FT MASSIVE SULFIDE VEIN, JUMBO LODE
Result 0.8% CU, 0.9% ZN, 0.05% PB, 0.03 OZ/TON AU, 0.03 OZ/TON AG, CHIP SAMPLE ACROSS 3 FT ZONE OF MINERALIZATION, ALL-AMERICAN LODE
Result DATA FROM ADGGS GR 15, TABLE I, P. 10

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Metavolcanic Rock > Mafic Metamorphic Rock > Greenstone
    Rock unit name Valdez Group
    Rock description Valdez Group
    Stratigraphic age (youngest) Late Cretaceous
    Stratigraphic age (youngest) Late Cretaceous
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Rock unit name Valdez Group
    Rock description Valdez Group;Valdez Group;Valdez Group;Valdez Group;Valdez Group

Nearby scientific data

(1) -146.27671, 61.01238

Geologic structures

Type Description Terms
Regional Shear Zones Developed In Slate Country Rock That Has Been Folded Against Graywacke
Local N-S Fault Runs About 1000 Ft W Of Mine, May Cut Off Ore Body; Minordrag Folds Suggest Anticline To The S

Ore body information

  • Strike N 75 W TO S 62 W
    Dip 40 TO 70 N
    Thickness 7M
    Length 300M

Controls for ore emplacement

  • Fracture Controlled

Comments on the geologic information

  • COUNTRY ROCK DOMINANTLY SLATES INTRUDED BY SILLS AND DIKES OF GREENSTONE; GREENSTONE BODY S OF MINE HAS EXPOSED DIMENSIONS OF 300 BY 1200 FT; AREA HAS BEEN METAMORPHOSED TO QUARTZ-ALBITE-EPIDOTE-BIOTITE SUBFACIES OF GREENSCHIST. BLACK SLATES INTERBEDDED WITH ARGILLITES, CHERTS, GRAYWACKE AND QUARTZITES. INTERBEDDED FLYSHOID SEDIMENTS DOMINATED BY BLACK SLATE. SCHISTOSE GREENSTONE (APPARENTLY AN ALTERED MAFIC-RICH GABBRO). GREENSTONE COMPOSED OF 70% ACTINOLITE AND 25% PLAGIOCLASE, AN60.

Economic information

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1901
Year of first production 1912
Year of last production 1919

Mining district

District name Port Valdez

Production statistics

  • Year 1917
    Accuracy Accurate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Minor Ore Silver Silver 12g/mt
    Minor Ore Gold Gold 2g/mt
    Major Ore Copper Copper 4wt-pct
  • Year 1918
    Accuracy Accurate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Minor Ore Silver Silver 7g/mt
    Minor Ore Gold Gold 1g/mt
    Major Ore Copper Copper 3wt-pct

Comments on the production information

  • FIRST ORE SHIPMENT IN 1911 OR 1912, REGULAR SHIPMENTS BETWEEN 1914 AND 1919; ORE WAS SHIPPED TO GRANBY CONSOLIDATED SMELTER AT ANYOX, BRITISH COLUMBIA AND TO TACOMA SMELTING COMPANY IN TACOMA, WASHINGTON

Comments on the workings information

  • JUMBO LODE: 4000 FT OF UNDERGROUND WORKINGS IN 4 INTERCONNECTED TUNNELS EACH BETWEEN 500 AND 900 FT LONG WITH 290 FT VERTICAL SEPARATION BETWEEN LOWEST AND HIGHEST TUNNEL, ALL BUT ONE CAVED BY 1964; ALL-AMERICAN LODE: OPEN CUTS AND SHALLOW SHAFT, CAVED BY 1964; SURFACE IMPROVEMENTS INCLUDED 5 1/4 MI AERIAL TRAM AND ORE BUNKERS; IN RUINS BY 1943

Comments on development

  • 15 PATENTED LODE CLAIMS AND 2 MILL SITES; ALL-AMERICAN LODE STAKEDIN 1901, DEVELOPED IN 1905 BY SHALLOW SHAFT; JUMBO LODE STAKED IN 1906,DEVELOPMENT BEGAN 1911, MAJOR UNDERGROUND WORK FROM 1913 TO SEP. 1918, SOME DIAMOND DRILLING AFTER THAT; 1982 REPORT OF RECENT EXPLORATION ACTIVITY

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A011481

Bibliographic references

  • Deposit

    USGS BULL 622, P. 151-153, 156-157, 187-188

  • Deposit

    USBM BULL 142, P. 38, 40

  • Deposit

    USBM BULL 153, P. 46-47

  • Deposit

    USGS BULL 692, P. 164-166, 168-171

  • Deposit

    ADGGS GR 15, P. 1, 5-12, 19

  • Deposit

    USBM IC 8626, P. 21

  • Deposit

    USGS OFR 80-892B, LOC. 32

  • Deposit

    ADGGS SR 31, LOC. 146

  • Other Database

    BAG-OFR-80-892B-32

  • Production

    USBM BULL 153, P. 47 AND ADGGS GR 15, P. 7

General comments

Subject category Comment text
Deposit CRUDELY STRATIFORM MASSIVE VEIN AND DISSEMINATED PYRITE-PYRRHOTITE-CHALCOPYRITE-SPHALERITE REPLACEMENT DEPOSITS; LOCALLY REMOBILIZED AND ENRICHED ALONG FRACTURES TO FORM CROSSCUTTING POLYMETALLIC SULFIDE-BEARING QUARTZ-CALCITE VEINS AND FRACTURE FILLINGS; GENERALLY RESTRICTED TOSHEAR ZONES STRIKING N 75 W TO S 62 W AND DIPPING 40-70 N; JUMBO LODE RANGED FROM A FEW IN TO 20 FT WIDE, AVERAGING 3 TO 4 FT OF ORE IN SHEAR ZONE ABOUT 1000 FT LONG; ALL-AMERICAN LODE IS WIDER BUT LOWER GRADE
Deposit ONLY COPPER MINE IN VALDEZ QUAD. WITH ANY SIGNIFICANT PRODUCTION; SOME RESERVES REMAIN IN JUMBO LODE, AND VERY LITTLE WORK HAS BEEN DONE ON ALL-AMERICAN LODE TO DATE; ACTIVE CLAIMS AND EXPLORATION REPORTED IN 1982; TWO SMALL OCCURRENCES OF CHALMERSITE REPORTED IN SOLOMON GULCH, BUT NOT AT MIDAS ; INFO.SRC : 1 PUB LIT; 2 UNPUB REPT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1985 Leonard, Kenneth R. (Elliott, R. L.) U.S. Geological Survey
Editor 14-APR-1994 Mosier, Dan U.S. Geological Survey