Post Deposit

The Post Deposit is a gold mine located in Eureka county, Nevada at an elevation of 5,561 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Post Deposit
Secondary: Post Mine
Secondary: Deep Post
Secondary: Lower Post
Secondary: Betze
Secondary: Betze Deposit
Secondary: Post/Betze
Secondary: Upper Post

Commodity

Primary: Gold
Secondary: Silver
Secondary: Arsenic

Location

State: Nevada
County: Eureka
District: Lynn; Carlin Trend, Bluestar/Goldstrike Subdistrict

Land Status

Land ownership: BLM Administrative Area
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.

Holdings

Not available

Workings

Not available

Ownership

Owner Name: Newmont Gold Co. (Newmont Mining Corp.)
Years: 1993 -

Owner Name: American Barrick Resources Corp. (Barrick Goldstrike Mine)
Years: 1993 -

Production

Not available

Deposit

Record Type: Site
Operation Category: Producer
Operation Type: Unknown
Year First Production: 1986
Discovery Year: 1982
Discovery Method: Other
Years of Production:
Organization:
Significant: N
Deposit Size: L

Physiography

General Physiographic Area: Intermontane Plateaus
Physiographic Province: Basin And Range Province
Physiographic Section: Great Basin
Physiographic Detail: Basin And Mountains

Mineral Deposit Model

Model Name: Carbonate-hosted Au-Ag

Orebody

Form: STRATIFORM (APPROXIMATELY)

Structure

Type: R
Description: Roberts Mountain Thrust

Type: L
Description: N-Nnw-Trending Zone Considered Main Hydrothermal Conduit; Nnw To N, And Ne-Striking Faults

Alterations

Alteration Type: L
Alteration Text: Decarbonization; Argillic And Silicic Hydrothermal; Oxidation

Rocks

Not available

Analytical Data

Analytical Data: 6.3 (LOWER POST/BETZE) (SEE LAUHA & BETTLES, 1993, FOR ADDITIONAL DRILLHOLE GEOCHEMISTRY).
Analytical Data: AU IS PART OF THIN RIND OF ARSENIAN PYRITE SURROUNDING GRAINS OF ARSENIC-POOR PYRITE. 2 TYPES OFAU-BEARING ARSENIAN PYRITE OR MARCASITE: EITHER 200 MICRONS OR 10-20 MICRONS, SIZES OCCUR IN APPROX. EQUAL PROPORTIONS. APPROX. AU:AG RATIOS, FROM 79 DRILL HOLES= 3.1 (POST OXIDE)

Materials

Ore: Gold
Ore: Marcasite
Gangue: Orpiment
Gangue: Gypsum
Gangue: Jarosite
Gangue: Sericite
Gangue: Calcite
Gangue: Hematite
Gangue: Alunite
Gangue: Kaolinite
Gangue: Quartz
Gangue: Pyrite
Gangue: Goethite
Gangue: Stibnite
Gangue: Barite
Gangue: Illite
Gangue: Dickite
Gangue: Realgar

Comments

Comment (Workings): OPEN PIT

Comment (Development): ANOMALOUS GOLD DETECTED IN OUTCROPS; OREBODY ENCOUNTERED IN FIRST DRILL HOLE. WESTERN STATES MINERALS COMMENCED MINING IN 1986, AND SOLD THE POST DEPOSIT TO BARRICK GOLDSTRIKE IN JANUARY 1987. LOWER POST WAS DISCOVERED BY DEEP DRILLING IN 1987. FURTHER DRILLING IN 1987 DEFINED THE BETZE OREBODY, "THE LARGEST DEPOSIT DESCOVERED TO DATE IN THE CARLIN TREND" (LAUHA & BETTLES, 1993). THE POST OREBODY IS MINED BY BARRICK GOLDSTRIKE AS A MAJOR ORE SOURCE FOR THE GOLDSTRIKE MINE PROCESSING FACILITIES. MOST RESERVES (SEE 1992 FIGURES) TO BE MINED FROM BETZE PIT, WHICH IS EXPECTED TO REACH DEPTH OF APPROX. 1,600 FT, WITH A STRIPPING RATIO OF 1:7. REFRACTORY ORE WILL BE PROCESSED BY AUTOCLAVE , WHICH IS EXPECTED TO REACH A DAILY CAPACITY OF 15,000 TONS/DAY IN 1993. THE NEWMONT PORTION OF LOWER POST WILL BE MINED SOMETIME AFTER 1993. ; ECON.COM: CYANIDATION RELATIVELY UNSUCCESSFUL ON REFRATORY SUFIDE ORE, SO BARRICK PROCESSES SUCH ORES BY ROASTING OR PRESSURE OXIDATION, THEN CYANIDATION.

Comment (Deposit): HIGHER GRADE ORE GENERALLY FOUND ADJACENT TO FAULTS AND IN CRESTS OF FOLDS, BELOW IMPERMEABLE UNITS. DEPOSIT CONTAINS BOTH SULFIDE AND OXIDE ORE. LOWER POST AND BETZE ARE HORIZONTALLY AND VERTICALLY ADJACENT PARTS OF THE SAME OREBODY, DISCOVERED AND THEN NAMED SEPARATELY. BETZE IS NW OF AND BELOW POST; LOWER POST IS DIRECTLY BELOW POST. SUPERGENE ALUNITE FROM POST K/AR DATED AT 8.48 TO 9.58 MA (AREHART, CITED IN LAUHA & BETTLES). POST OREBODY IS OXIDE, HOSTED BY VININI FM. LOWER POST/BETZE ARE REFRACTORY, HOSTED BY POPOVICH & TO LESSER EXTENT ROBERTS MT. FM. SECONDARY MINERALIZATION TREND AT LOWER POST/BETZE IS N40-70E. TOP, BOTTOM, AND LENGTH ARE MAXIMUM DIMENSIONS FOR ALL POST/BETZE OREBODIES, COMBINED.

Comment (Commodity): AU OCCURS AS MICRON TO SUBMICRON-SIZED PARTICLES ASSOCIATED WITH QUARTZ AND CLAYS IN THE OXIDE ZONES AND WITH PYRITE AND MARCASITE IN THE SULFIDE ZONES. SIMPLE REFRACTORY ORE IN THE LOWER PORTIONS OF THE LOWER POST/BETZE OREBODY IS CHARACTERIZED BY SILICIFICATION WITH KAOLINITE & 5-10% DISSEMINATED PYRITE. CARBON FOUND DISTAL AND PROBABLY UNRELATED TO THE OREBODIES. INCREASING AU GRADES ASSOCIATED WITH INCREASING AMOUNTS OF PYRITE/MARCASITE.

Comment (Reserve-Resource): BONHAM, 1989 GIVES BREAKDOWN OF 1987 BARRICK RESERVES: POST OXIDE-1.4 MILLION OZ AU; DEEP POST/BETZE-7.3 MILLION OZ AU. ANNUAL RESERVE OR RESOURCE/RESERVE FIGURES ARE SHOWN IN THE ANNUAL EDITION OF THE NEVADA MINERAL INDUSTRY. ONLY THE EARLIEST 1983 FIGURES FROM THE 1989 EDITION ARE GIVEN HERE. 1992 FIGURES AS OF DEC 31, 1991. 1993 FIGURES, EXCEPTING * ARE PRESUMABLY ONLY FOR BARRICK'S ORE. * IS PRESUMABLY A TOTAL FOR BARRICK + NEWMONT RESERVES.

Comment (Production): BARRICK AND NEWMONT EACH MINE PART OF THE DEPOSIT SEPARATELY.

Comment (Geology): AREHART, FOLAND, ET AL. (1993, LATEST PUB. ON THIS DEPOSIT) GIVES AGE OF MINERALIZATION AS 117 MA. OTHER POSSIBLE AGES OF MINERALIZATION ARE: 36-37 MA, 39 MA, OR 158 MA. THE LOWER POST, BETZE, AND DEEP POST DEPOSITS LIE BENEATH THE POST DEPOSIT AND SPACIALLY DISTINCT FROM POST. POST LIES ON THE UPPER PLATE OF THE ROBERTS MOUNTAIN THRUST; BETZE & LOWER POST ARE IN THE LOWER PLATE OF THIS THRUST. LOWER POST AND BETZE ARE A SINGLE OREBODY (AREHART ET AL). ASSOCIATED IGNEOUS ROCKS, SHOWN ABOVE, ALSO HOST ORE IN THE POST DEPOSIT. NNW TO N FAULTS AND SOME NE FAULTS SHOW MOVEMENT AFTER ORE FORMATION. FAULTING CAUSED BRECCIATION AND PREPARATION FOR HIGHER GRADE MINERALIZATION. COLLAPSE & HYDROTHERMAL BRECCIAS OF ABOVE-NAMED HOST ROCKS ALSO HOST ORE. MINOR AU MINERALIZATION FOUND IN GOLDSTRIKE INTRUSIVE, USUALLY ALONG FAULTS OR JOINTS. AMERICAN BARRICK AND NEWMONT USE DIFFERENT NAMES FOR THE SAME UNITS (SUCH AS ROBERTS MOUNTAIN FM.).

Comment (Deposit): THIS RECORD INCLUDES INFORMATION FROM MRDS RECORDS M242940 AND W700373, WHICH HAVE BEEN DELETED.

References

Reference (Deposit): ROCKY MOUNTAIN PAY DIRT, MARCH, 1988, P. 4A-5A.

Reference (Deposit): ROCKY MOUNTAIN PAY DIRT, JUNE, 1988, P. 3A.

Reference (Deposit): KNUTSEN, G. C., BETTLES, K. H., SULFRIAN, C. E., AND ZIMMERMAN, C. J., 1987, DISCOVERY AND GEOLOGY OF THE POST GOLD DEPOSIT, EUREKA COUNTY, NEVADA: SOCIETY OF MINING ENGINEERS PREPRINT NUMBER 87-86, 6 P.

Reference (Deposit): AREHART, G. B., ELDRIDGE, C.S., CHRYSSOULIS, S.L., KESLER, S.E., 1993, ION MICROPROBE DETERMINATION OF SULFUR ISOTOPE VARIATIONS IN SULFIDES FROM THE POST/BETZE SEDIMENT-HOSTED DISSEMINATED GOLD DEPOSIT, NEVADA, USA, GEOCHIMICA ET COSMOCHIMICA ACTA, V.57, PP.1505-1519

Reference (Deposit): ALBINO, GEORGE, 1993 ORAL COMMUNICATION, JULY 22, 1993, RENO, NV

Reference (Production): ALL 1980-1988 BARRICK FIGURES ALL IN BONHAM, 1989. 1988 NEWMONT AND 1989 BARRICK FIGURES FROM BONHAM AND HESS, 1990.

Reference (Deposit): BONHAM, H.L., 1988, BULK-MINEABLE PRECIOUS-METAL DEPOSITS, IN, THE NEVADA MINERAL INDUSTRY, 1987, NEVADA BUREAU OF MINES AND GEOLOGY MI-1987

Reference (Deposit): BONHAM, H.L., 1986, BULK-MINEABLE PRECIOUS-METAL DEPOSITS AND PROSPECTS, NEVADA BUREAU OF MINES AND GEOLOGY MAP 91

Reference (Deposit): BONHAM, H.L., 1991, BULK-MINEABLE PRECIOUS-METAL DEPOSITS AND PROSPECTS, NEVADA BUREAU OF MINES AND GEOLOGY MAP 91, 3RD ED.

Reference (Deposit): ENVIRONMENTAL ASSESSMENT, 1987, NEVADA BUREAU OF MINES AND GEOLOGY FILES

Reference (Deposit): NEVADA BUREAU OF MINES AND GEOLOGY MINING DISTRICT FILE 115, NUMEROUS PRESS CLIPPINGS

Reference (Deposit): LAUHA, E.A., AND BETTLES, K.H., 1993, A GEOLOGIC COMPARISON OF THE POST/BETZE AND PURPLE VEIN DEPOSITS OF THE GOLDSTRIKE AND MEIKLE MINES, NEVADA, SME PREPRINT 93-170, PRESENTED AT SME ANNUAL MEETING, RENO, NV, FEB. 15-18, 1993

Reference (Deposit): BONHAM, H.L., AND HESS, R.H., 1990, BULK-MINEABLE PRECIOUS-METAL DEPOSITS, IN, THE NEVADA MINERAL INDUSTRY, 1989, NEVADA BUREAU OF MINES AND GEOLOGY MI-1989, P21

Reference (Deposit): AREHART, G.B., FOLAND, K.A., NAESER, C.W., AND KESLER, S.E., 1993, 40AR/39AR, K/AR, AND FISSION TRACK GEOCHRONOLOGY OF SEDIMENT-HOSTED DISSEMINATED GOLD DEPOSITS AT POST-BETZE, CARLIN TREND, NORTHEASTERN NEVADA; ECONOMIC GEOLOGY, V. 88, NO. 3, P. 622-646

Reference (Deposit): BONHAM, H.L., 1989, BULK-MINEABLE PRECIOUS-METAL DEPOSITS, IN, THE NEVADA MINERAL INDUSTRY, 1988, NEVADA BUREAU OF MINES AND GEOLOGY MI-1988, P21

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.