Northumberland Mine

Site Name

Primary: Northumberland Mine
Secondary: Blue Bell
Secondary: Monitor
Secondary: Last Chance Group
Secondary: Cyprus-Northumberland Mine

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Commodity

Primary: Gold
Primary: Silver
Tertiary: Arsenic
Tertiary: Iron

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Location

State: Nevada
County: Nye
District: Northumberland District

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Land Status

Land ownership: National Forest
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

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Holdings

Not available

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Workings

Type: Surface/Underground

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Ownership

Owner Name: Cyprus Mines Corp.
Years: 1985 -

Owner Name: Cyprus Mines Corp
Years: 1985 -

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Production

Year: 1984
Time Period: 1981-1984
Material type: ORE AU
Description: Cp_Grade: ^0.045-0.07 Oz Au/Ton

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Deposit

Record Type: Site
Operation Category: Producer
Operation Type: Unknown
Discovery Year: 1866
Years of Production:
Organization:
Significant: N
Deposit Size: M

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Physiography

Not available

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Mineral Deposit Model

Model Name: Carbonate-hosted Au-Ag

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Orebody

Not available

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Structure

Type: R
Description: Reg.Struct: Major Thrust Sheets

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Alterations

Alteration Type: L
Alteration Text: Silicification, Sericitization, Jasperoid, Argillic

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Rocks

Name: Quartz Monzonite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Late Jurassic

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Analytical Data

Analytical Data: SAMPLES FROM THE LAST CHANCE CONTAIN $1-$3 IN GOLD AND 5-40 OUNCE SILVER PER TON.

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Materials

Ore: Cerargyrite
Gangue: Quartz
Gangue: Barite
Gangue: Sericite

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Comments

Comment (Production): AMOUNT UNKNOWN

Comment (Workings): OPEN PIT (LARGE); ORE CRUSHER, MILL BUILDING; ALL ON SITE OF EARLIER ESTENSIVE UNDERGROUND WORKINGS CONSISTING OF 4000 FT OF DEVELOPMENT AT THE BLUE BELL, 1600 FT IN 3 ADITS AT THE LAST CHANCE. ORE IS HAULDE TO HEAP LEACH PADS AT MOUTH OF WEST NORTHUMBERLAND CANYON IN BIG SMOKY VALLEY.

Comment (Location): UNSURVEYED TOWNSHIP AND RANGE . INFO FROM LAND.ST :(1972)

Comment (Deposit): 3 MAIN VEINS: LADY CIMMINGS, NORTHUMBERLAND AND DETROIT VEINS. DISSEMINATED GOLD MINERALIZATION OCCURS LARGELY IN A CARBONACEOUS SHALE BED NEAR CONTACT OF GRANITIC INTRUSIVE. ORE IS PRESENT IN BOTH UPPER AND LOWER PLATE ROCKS ALON THRUST FAULT. SILTSTONE AND LIMESTONE HAVE BEEN CONSIDERABLY REPLACED BY JASPEROID, WHICH IS LOCALLY HYDROTHERMALLY BREDDIATED. LATE-STAGE VEINLETS CONTAIN COARSE BARITE CRYSTALS. ORE IS STRONGLY ALTERED, FE OXIDE-STAINED THIN-BEDDED CARBONACEOUS SHALE. ON THE WEST SIDE OF THE CANYON ARE HIGHLY ALTERED, FRACTURED VOLCANICS. GOLD OCCURS IN MICROFRACTURE FILLINGS OF QUARTZ AN BARITE IN SILICIFIED HORIZONS OF THE ORDOVICIAN POGONIP GROUP ASSOCIATED WITH MARGINS OF A MINZONITE INTRUSIVE.

Comment (Development): THE SILVER WAS DISCOVERED IN 1866 AND MINITOR-BLUE BELL ORE WAS TREATED AT A 10-STAMP MILL ATA SPRING IN WEST NORTHUMBERLAND CANYON, NOW MARKED BY STONE RUINS. SPORADIC SILVER MINING CONTINUED UNTIL 1891. GOLD WAS DISCOVERED JUST EAST OF THE OLD SILVER WORKINGS IN 1936 AND THE NORTHUMBERLAND MINING CO WAS OPERATING IN 1939, UNTIL 1942 WHEN THE GOLD MINE WAS CLOSED. GOLD EXPLORATION WAS RESUMER IN THE 1960'S BY HOMESTAKE AND OTHERS -IDAHO MINING CO-1970'S RESULTING IN THE INING OF THE LOW-GRADE GOLD DEPOSIT IN 1981, FIRST BY AMOCO (LATERCYPRUS MINERALS), WITH MINING CONTINUING TO PRESENT. THAT RATE OF 3000 TPD HEAP LEACHED. STANDARD OIL CO SPUN OFF CYPRUS IN 1985.

Comment (Geology): DISSEMINATED GOLD MINERALIZATION OCCURS LARGELY IN A CARBONACEOUS SHALE BED NEAR CONTACT OF GRANITIC INTRUSIVE. ORE IS PRESENT IN BOTH UPPER AND LOWER PLATE ROCKS ALONG THRUST FAULT. SILTSTONE AND LIMESTONE HAVE BEEN CONSIDERABLY REPLACED BY JASPEROID,WHICH IS LOCALLY HYDROTHERMALLY BRECCIATED. LATE STAGE VEINLETS CONTAIN COARSE BARITE CRYSTALS.

Comment (Reserve-Resource): 8 MILLION TONS ORE WERE REPORTED, BUT 20 MILLION TONS IS PROBABLY CLOSER TO THE SIZE OF THE DEPOSIT (1981). 1986-LEACHING OF EXISTING HEAPS ONLY.

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References

Reference (Deposit): NBMG BULL 50.

Reference (Deposit): UNPUBLISHED NOTES, NBMG FILE42,ITEM 2

Reference (Deposit): NEVADA MINING ASSOCIATION NEWSLETTER, OCT., 1980.

Reference (Deposit): FIELD EXAMINATION OF THE PROPERTY, AND DISCUSSION BETWEEN L.J. GARSIDE AND H.F. BONHAM,JR.,NBMG, MAY, JULY, 1981.

Reference (Deposit): SMITH, P. AND BENTZ, J., 1981, NBMG FIELD EXAMINATION.

Reference (Deposit): TINGLEY, J.V. AND QUADE, JACK, 1986, NBMG OFR 86-14.

Reference (Deposit): GOLDSTEIN, I.J., 1973, GOLD MINERALIZATION AT THE NORTHUMBERLAND GOLD MINE, NYE CO., NV; GSA ABS.-CARD. SECTION

Reference (Deposit): MCKEE, E.H., 1974, NBMG REPROT 19

Reference (Deposit): KLEINHAMPL, F.J. AND ZIONY, J.I., 1984085, NBMG BULL 99 A AND B.

Reference (Deposit): OTT, L.E., 1983, GEOL. AND OPELICALIZATION AT NORTHUMBERLAND GOLD MINE, NYE CO. NV; MS THESIS; MONTANA COLLEGE OF MINERAL SCIENCE AND TECHNOLOGY.

Reference (Deposit): MOTTER, J.W. AND CHAPMAN, P.E., 1984, AEG FIELD TRIP GUIDEBOOK.

Reference (Deposit): NBMG MI-1987

Reference (Deposit): NBMG MINING DISTRICT FILE 242, NEWS CLIPPINGS.

Reference (Deposit): NBMG, 1994, MI-1993

Reference (Production): KLEINHAMPL AND ZIONY (1984-5), NBMG MI-1987. NBMG MI-1993

Reference (Reserve-Resource): 1981 FIELD EXAMINATION AND DISCUSSION BETWEEN L.J. GARSIDE AND H.F. BONHAM,JR.,MAY,JULY,1981. NBMG MI-1993

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Nevada Gold

Nevada has a total of 368 distinct gold districts. Of the of those, just 36 are major producers with production and/or reserves of over 1,000,000 ounces, 49 have production and/or reserves of over 100,000 ounces, with the rest having less than 100,000 ounces. Read more: Gold Districts of Nevada.