Dernan Property

Site Name

Primary: Dernan Property
Secondary: Reilly Mine
Secondary: NBMG Sample Site 2613

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Commodity

Primary: Tungsten
Secondary: Iron
Secondary: Manganese
Tertiary: Copper
Tertiary: Molybdenum
Tertiary: Gold
Tertiary: Zinc
Tertiary: Lead
Tertiary: Barium-Barite
Tertiary: Titanium, Metal
Tertiary: Beryllium
Tertiary: Bismuth
Tertiary: Cobalt
Tertiary: Nickel

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Location

State: Nevada
County: Humboldt
District: Potosi District; Getchell District

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Land Status

Land ownership: Private
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: Union Carbide
Years: 1964 -

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Production

Year: 1955
Time Period: 1943-1955
Material type: WO3
Description: Cp_Grade: ^0.53-0.7 % Wo3

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Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Contact Metamorphic
Operation Type: Unknown
Year First Production: 1942
Discovery Year: 1915
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: W skarn

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Orebody

Form: TABULAR, ALONG IGNEOUS CONTACT

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Structure

Type: R
Description: Getchell Fault Cuts S. End Of Ore Body

Type: L
Description: Fault Along Front Of Range

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Alterations

Not available

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Rocks

Name: Limestone
Role: Host
Age Type: Associated Rock Unit
Age Young: Late Cretaceous

Name: Limestone
Role: Host
Age Type: Host Rock Unit
Age Young: Late Cambrian

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Analytical Data

Analytical Data: . SAMPLE 2613 OF PALE AMBER GARNET SKARN WITH SUBHEDRAL GARNET, SCHEELITE SPECKS, CHALCOPYRITE, MOLYBDENITE, CONTA-INS +20 % FE, 1% MG, +20 % CA, 0.07 % TI, +5000 PPM MN, 2 PPM -AG, 30 PPM B, 20 PPM BA, 1.5 PPM BE, 20 PPM BI, 10 PPM CO, 100-0 PPM CU, 1000 PPM MO, 5 PPM NI, 50 PPM PB, 150 PPM SN, 1000 P-PM V, 5000 PPM W.

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Materials

Ore: Molybdenite
Ore: Sphalerite
Ore: Scheelite
Ore: Chalcopyrite
Ore: Galena
Ore: Pyrite
Gangue: Garnet
Gangue: Wollastonite
Gangue: Pyroxene

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Comments

Comment (Workings): 8 PITS

Comment (Deposit): Discovery Year: WWI ERA

Comment (Deposit): MINE OPERATED AS OPEN PIT FROM 1942 TO 1945. SOME PRODUCTION BY U.S. VANADIUM CORP FROM 1945 TO 1948. MINE WAS REOPENED IN 1952, AND OPERATED BOTH UNDERGROUND AND OPEN PIT THROGH 1957. IN 1945, A MILL WAS ERECTED BY NORTHERN NEVADA MINING CORP, AND A SMALL AMOUNT OF ORE WAS TREATED BEFORE IT WAS BOUGHT BY U.S. VANADIUM CORP. (LATER UNION CARBIDE NUCLEAR CORP.) THE AREA WAS PROSPECTED DURING WWI, BUT LITTLE, IF ANY, TUNGSTEN WAS THEN PRODUCED. RILEY AND RILEY EXTENSION MINES COMPRISE THE LARGEST SINGLE TACTITE DEPOSIT IN THE DISTRICT EARLY EXPLORATION WAS FOR SILVER ORE. THE PRESENCE OF SCHEELITE WAS KNOWN SINCE ABOUT 1917, BUT IT WAS NOT MINED UNTIL WORLD WAR II. SCHEELITE ORE WAS MINED FROM A SERIES OF EIGHT PITS ALONG THE TACTITES. ; INFO.SRC : 1 PUB LIT; 2 UNPUB REPT; 3 FIELD OBSERV

Comment (Commodity): 1943-1944, 80,000 TONS ORE AVG. 0.63% WO3=50,400 UNITS WO3; 1945, 8500 TONS ORE AVG. 0.70% WO3=5950 UNITS WO3; 1952-1955, 264,600 TONS ORE AVG. 0.57% WO3 = 150,822 UNITS WO3. PRODUCTION FROM 1945 TO 1948 IS UNKNOWN, BUT IT WAS SUBSTANTIAL, AS THE RILEY MINE WAS NEVADA'S 2ND LARGEST PRODUCER OF TUNGSTEN CONCENTRATES IN 1947.

Comment (Reserve-Resource): SUBSEQUENT PRODUCTION FROM 1945 TO 1957 TOTALLED ABOUT 430000 TONS ORE YIELDING 280000 UNITS WO3, WHICH WOULD HAVE- DEPLETED MOST OF THESE RESERVES, BUT A SMALL TONNAGE OF ORE R-EMAINED UNMINED BELOW THE LOWEST LEVEL OF THE MINE AND BETWEEN- THAT LEVEL WORKINGS AND THE ADJACENT RILEY EXTENSION PROPERTY- LINE

Comment (Production): OVER 206,000 UNITS WO3 PRODUCED FROM 1943-1945 AND 1952-1955, PLUS A SUBSTANTIAL AMOUNT PRODUCED FROM 1945-1948.

Comment (Geology): THE GRANODIORITE CONTACT TRENDS GENERALLY NORTH: THE "EAST VEIN" EXTENDS ALONG THE GRANODIORITE CONTACT FOR ABOUT 1600 FEET AT SURFACE, MINED ON BOTH RILEY AND RILEY EXTENSION PROPERTIES. THE MAIN ORE BODY WAS A TABULAR TACTITE BODY MINED FOR APPROX. 800 FT. DOWN DIP, AVERAGING 10 FT. THICK. THE SHEAR ZONE EXPOSED IN THE CUTS AT THE RILEY MINE CONTAIN SEVERAL TENS OF FEET OF MARGINAL GOLD ORE (GETCHELL-TYPE). TUNGSTEN ORE BODIES ARE LOCALIZED IN "TROUGHS" FORMED BY JOGS IN THE ATTITUDE OF THE IG NEOUS/SE DIMENTARY CONTACT. THERE ARE 4 SUCH DISTINCT ORE BODIES.

Comment (Development): THE PROPERTY CONSISTS OF 80 ACRES OF PATENTED GROUND THAT IS PART OF THE TOM DERNAN ESTATE. IT WAS LEASED TO MR. J-. E. RILEY OF RENO IN THE FALL OF 1942 AND WAS DEVELOPED AND -OPERATED BY HIM IN 1943-1944, YIELDING ABOUT 80000 TONS ORE AV-ERAGING 0.53 % WO3, THAT WAS SOLD TO METALS RESERVE CO FOR THE- NEARBY GETCHELL STOCKPILE. A MILL WAS BUILT ON THE PROPERTY, -IN THE WINTER OF 1944-45 AND AN ADDITIONAL 8000 TONS ORE WAS M-INED AND MILLED BEFORE THE PROPERTY WAS SOLD TO THE U. S. VANA-DIUM CORP. (LATER UNION CARBIDE CORP.) IN OCTOBER, 1945. ALL O-F THE ORE PRODUCED TO THE END OF 1945 CAME FROM 8 OPEN PITS AL-ONG THE OUTCROP. IN 1945 THE USBM EXPLORED THE DEPOSIT BY 15 D-IAMOND DRILL HOLES HAVING AN AGGREGATE LENGTH OF 2630 FT, AND -ADDED GREATLY TO THE KNOWN RESERVES. FROM LATE 1945 TO 1948 AN-D FROM 1952 TO 1957 THE PROPERTY WAS OPERATED BY U. S. VANADIU-M CORP. AND THEN UNION CARBIDE CORP, WITH A LARGE PRODUCTION O-F ORE FROM OPEN PITS AND UNDERGROUND WORKINGS.

Comment (Deposit): THE PROPERTY IS ALONG THE EAST CONTACT OF THE NORTHERN LOBE OF THE OSGOOD STOCK WITH LIMESTONE AND INTERBEDDED ARG-ILLITE STRIKING N, DIP 30-60 E (BOTH BEDDING AND CONTACT). A B-AND OF TACTITE 3-20 FT THICK IS PRESENT ALONG MUCH OF THE CONT-ACT AND IN PLACES EXTENDS UP TO 40 FT OUT INTO THE LIMESTONE. -THE TACTITE EXTENDS AS MUCH AS 500 FT DOWN DIP TO THE POINT WH-ERE THE GRANODIORITE CONTACT DROPPED BELOW THE E-DIPPING LIMES-TONES. AT THE SOUTH END OF THE PROPERTY THE TACTITE LENSES ARE- CUT OFF BY THE GETCHELL FAULT. THE FOUR MAJOR OREBODIES OCCUR- ALONG A STRIKE LENGTH OF 1700 FT ALONG THE CONTACT, LOCALIZED- BY TROUGHS OF E-DIPPING FOLDS CUT BY THE CONTACT. THE ORE ZON-ES EXTENDED ONTO THE RILEY EXTENSION MINE PROPERTY TO THE NORT-H

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References

Reference (Deposit): WILLDEN, R, 1964, GEOLOGY AND MINERAL DEPOSITS OF HUMBOLDT CO., NEV; NEV. BUREAU OF MINES BULL. 59.

Reference (Deposit): HOTZ, P.E., AND WILLDEN, R., 1964, GEOLOGY AND MINERAL DEPOSITS OF THE OSGOOD MOUNTAINS QUAD. HUMBOLDT CO., NEV; U.S.G.S. PROF. PAPER 431.

Reference (Deposit): HOBBS, SW. AND CLABAUGH, S.E., 1946, TUNGSTEN DEPOSITS OF THE OSGOOD RANGE, HUMBOLDT COUNTY, NEV. UNIV. NEV. BULL. V. 40, NO. 5; GEOL & MIN. SER. NO. 44

Reference (Deposit): HOLMES, G.H., 1946, EXPLORATION OF THE RILEY TUNGSTEN MINE, HUMBOLDT CO., NEVADA; U.S.B.M. REPT INV. 3945

Reference (Deposit): STAGER, H. K., IN PREPARATION, NBMG BULLETIN ON TUNGSTEN DEPOSITS OF NEVADA

Reference (Deposit): TINGLEY, J. V., 6 SEP 84, NBMG FIELD EXAMINATION AND SAMPLE ANALYSIS.

Reference (Deposit): NBMG MINING DISTRICT FILE 136, ITEM 26, 1963, USBM UNPUBLISHED DATA.

Reference (Deposit): SCHILLING, JOHN, 1968, MOLYBDENUM RESOURCES OF NEVADA; NBMG OFR 79-3

Reference (Production): HOTZ, P.E., WILLDEN, R., 1964; STAGER, IN PREP.

Reference (Reserve-Resource): STAGER, H. K., IN PREP

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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.