Pipeline & South Pipeline Mines

Site Name

Primary: Pipeline & South Pipeline Mines
Secondary: Cortez Joint Venture Mines
Secondary: Pipeline Complex
Secondary: South Pipeline Extension deposit (Crossroads)
Secondary: Crescent Pit

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Commodity

Primary: Gold
Secondary: Mercury
Secondary: Silver

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Location

State: Nevada
County: Lander
District: Bullion District

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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.
Administrative Organization: Battle Mountain BLM-administrative district

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Holdings

Not available

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Workings

Not available

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Ownership

Owner Name: Barrick Gold Corp.
Percent: 100.0
Info Year: 2009
Years: 2008 -

Owner Name: Cortez Joint Venture: Kennecott Explorations
Percent: 40.00
Info Year: 2004

Owner Name: Cortez Joint Venture: Placer Dome, Inc.
Percent: 60.00
Info Year: 2004

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Producer
Deposit Type: Sediment-hosted Au
Plant Type: Leach
Operation Type: Surface
Mining Method: Open Pit
Milling Method: Heap Leach-Agglomerate-Carbon Column-Merrill-Crowe
Year First Production: 1996
Discovery Year: 1991
Years of Production:
Organization:
Significant: Y

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Physiography

Not available

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Mineral Deposit Model

Model Name: Sediment-hosted Au

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Orebody

Form: irregular

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Structure

Type: L
Description: range-front fault

Type: R
Description: Roberts Mountains thrust fault

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Alterations

Alteration Type: L
Alteration Text: The main alteration evident is argillization and silicification of the host Silurian Roberts Mountains Formation. The host rock is also decalcified and oxidized to varying degrees.

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Rocks

Name: Alluvium
Role: Host
Age Type: Host Rock
Age Young: Quaternary

Name: Siltstone
Role: Host
Description: calcareous
Age Type: Host Rock
Age Young: Early Devonian
Age Old: Wenlock

Name: Carbonate
Role: Host
Age Type: Host Rock
Age Young: Early Devonian
Age Old: Wenlock

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Analytical Data

Not available

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Materials

Ore: Quartz
Ore: Pyrite
Gangue: Gold

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Comments

Comment (Commodity): Ore Materials: free gold

Comment (Commodity): Gangue Materials: quartz iron oxides, pyrite

Comment (Workings): Conventional open-pit mining methods are used for the Pipeline and South Pipeline deposits, scheduled in nine stages. From 2001?05, production is expected to average 70Mt/y. Pit wall slopes vary from 34? to 50?. Mining is carried out with electric shovels, a hydraulic shovel and haul trucks. A fleet of miscellaneous equipment includes rotary/hammer blasthole drills, wheel loaders, bulldozers, graders and water trucks. A pit dewatering system including 40 wells helps to prevent water inflows, the water being transported from the pit to a series of shallow infiltration ponds for recycling.

Comment (Economic Factors): 6-2-97: IN 1981, THE MILL PROCESS WAS CONVERTED TO A CIL PLANT FROM A STANDARD MERRILL-CROWE PLANT.

Comment (Production): FIRST GOLD POUR MARCH 1997, MINE LIFE IS EXPECTED TO BE 12 YR. SEE CORTEZ FILE 0320150509 FOR PRODUCTION:

Comment (Deposit): The Pipeline deposits are situated along the Cortez/Battle Mountain trend in the north-central Nevada Basin-and-Range province. Submicroscopic free gold particles are evenly distributed throughout carbonate host rocks commonly in association with secondary silica, iron oxides, or pyrite. The two principal lithological units are a sheared and altered thinly-bedded calcareous siltstone and quaternary alluvium varying from chert, argillite, siltstone, limestone and quartzite to fine sands and silts. The Pipeline/South Pipeline/South Pipeline Extension (Crossroads area) deposits are comprised of two mineralized zones: a shallow zone with depth to the top of the zone ranging from 10 metres to 180 metres below the pre-mining surface and a deeper zone that begins approximately 300 metres below the pre- mining surface. Both mineralized zones are low angle and tabular and range from 15 metres to 110 metres thick and dip to the east. The deposits are part of the same mineralized system and occupy area approximately 3,000 metres in a northerly direction and about 1,000 metres in an easterly direction. Gold mineralization occurs in a low-angle tabular zone (the Duplex zone) within the Silurian Roberts Mountains Formation. Gold is microscopic, occurring as sparse 1-2 micron, irregularly shaped blebs disseminated through the matrix of the host rock. Gold is commonly associated with silica, hematite, on iron oxide pseudomorphs after pyrite, in illitic matrix material, and in quartz veinlets. Unlike the nearby Cortez deposits, there are no dikes present at the Pipeline deposits.

Comment (Development): The Pipeline deposit was discovered in 1991 by Cortez Mine geologists during deep condemnation drilling in the area of a proposed heap leach expansion. The South Pipeline deposit was discovered later the same year by Cortez geologists targeting fault intersections similar to those at Pipeline. The South Pipeline project involves an approximately 4,000 acre mining claim position in the Cortez District, located in Crescent Valley, Lander County Nevada. It is approximately 500 feet south of the Pipeline deposit being mined by Cortez. Royal Gold held a 20% net profits interest royalty in the South Pipeline Project. In the combined Pipeline/South Pipeline deposits (excluding the Crescent Pit), drilling delineated 87.3 million tons of ore containing 6.75 million mineable ounces of gold. The total geologic resource was calculated to be 136.7 tons containing 8.7 million ounces of gold. Mining began at the South Pipeline Crescent pit in June 1994 on the 5060 bench. Three stages of mining were then planned for each of the two deposits. Stage I mining of the Pipeline deposit began in March, 1996. In 2000, the South Pipeline Plan of Operations permitting was approved and the South Pipeline Extension deposit (Crossroads Area) was discovered.In 2001, A Plan of Operations was submitted for the Pipeline Expansion Project. All requisite permits for the development of the Pipeline/South Pipeline production through Stage 7 and all Stages through the 4120 elevations have been obtained and are in good standing. Additional permitting is in progress to expand the Pipeline/South Pipeline Pit to include Stages 8 & 9, the Gap and Crossroads Pit and to mine below the 4120 elevation. Approximately 224,000 feet of exploration, development, and condemnation drilling were completed in 2002 on the Pipeline/South Pipeline/South Pipeline Extension property. Exploration will continue in the Pipeline/South Pipeline area, but potential is limited as the margins of the deposits are becoming better defined. The exploration in 2003 focused on continued refinement of the areas around the deposits. Attractive drill intercepts requiring follow up, as well as geologic and geophysical targets, are present to the south of the South Pipeline deposit along the projected strike of the Pipeline fault. These targets could generate additional mineralized material.

Comment (Deposit): 6-2-97: THE MINE IS PRODUCING COMMERCIAL QUANTITIES OF AU. THE STRIPPING RATIO IS 6.8 TONNES OF WASTE FOR EVERY TONNE OF ORE. THE OPERATION HAS A MINE LIFE OF 15 YRS. 310,000 OZ AU IS EXPECTED TO BE PRODUCED A YR (MUCH OF WHICH WILL BE PROCESSED THROUGH A NEW CARBON-IN-LEACH MILL). THIS OPEN PITABLE ORE BODY ALONG WITH THE SOUTH PIPELINE ORE BODY IS PART OF THE CORTEZ GOLD MINE JV: MAS SEQ#0320150509: AS OF 12/31/97 RESERVES/RESOURCES WILL BE INCLUDED IN THE CORTEZ GOLD OPERATIONS FILE; MAS SEQ# 03201500509: THE SOUTH PIPELINE OP (MAS SEQ 0320150610), SHOULD BE IN DEVELOPMENT BY 1997, PRODUCTION IN 1998. THE TWO PITS WILL EVENTUALY BE COMBINED INTO A SINGLE PIT.

Comment (Geology): Two principal lithologic units are identified within the Pipeline/South Pipeline/South Pipeline Extension (Crossroads area) deposit area - the Silurian Roberts Mountains Formation (?Srm?) and the Quaternary alluvium. The Pipeline/South Pipeline/South Pipeline Extension (Crossroads area) deposits are hosted in the sheared and variably altered Srm, a thinly bedded calcareous siltstone (silty carbonate unit). The thickness of the Srm exceeds 600 metres in the deposit area. The Pipeline/South Pipeline/South Pipeline Extension (Crossroads area) deposit area is covered by Quaternary alluvium ranging in thickness from approximately 10 metres to greater than 200 metres. The alluvium-bedrock contact dips gradually to the east (less than 10 degrees) at an angle shallower than and sub-parallel to the bedding of the strata below.

Comment (Identification): Record replaces MRDS records #MP90059 and MP90061 and includes all information from the earlier records which should be deleted.

Comment (Location): South Pipeline is approximately 500 feet south of the Pipeline deposit. Coordinates are for the center of the pit that includes both deposits.

Comment (Economic Factors): Production: From 1994 to 1996, the combined Pipeline - South Pipeline (Crescent) deposits produced 10.6 tonnes of gold and 0.55 tonnes of silver from 1843 kilotonnes of ore. (These figures include production from Gold Acres). In 1997 Placer Dome's Cortez Gold Mines (including Pipeline) produced 406,551 troy ounces of gold. In 2003, the Placer Dome Pipeline mine produced over a million ounces of gold. In 2004 the Placer Dome Pipeline mine production was expected to reach 940,000 ounces. Reserves/Resources - Pipeline: In 1991 Cortez reported a geologic resource of 11.3 million tons of ore grading 0.237 ounces of gold per ton. In 1993 Cortez reported a geologic resource of 35.3 million tons of ore grading 0.120 ounces of gold per ton. In 1994 Cortez reported reserves of 21.2 million tons of ore grading 0.145 ounces of gold per ton plus additional geologic resource of 8.3 million tons of ore grading 0.035 ounces of gold per ton. Reserves/Resources - South Pipeline: In 1992 reserves were reported at 9 million tons of ore grading 0.082 ounces of gold per ton. In 1993 a geologic resource was reported of 31.4 million tons of ore grading 0.106 ounces of gold per ton. In 1994: geologic resource was reported of 76.5 million tons of ore grading 0.048 ounces of gold per ton. Current reserves are combined with that for the whole Cortez operations and not listed separately. In 1994, the combined Pipeline - South Pipeline (Crescent) deposits were estimated to contain a remaining resource of 166,920 kilotonnes of ore containing 350 tonnes of gold (Long and others, 1998). In May 1997, Placer Dome U.S. Inc. informed Royal Gold that they estimated a proven and probable ore reserve of 52.7 million tons of ore, averaging 0.054 ounces of gold per ton, containing approximately 2.85 million ounces of gold, for South Pipeline. A decision to reclassify some, or all, of the additional mineralized material reported herein to proven and probable ore reserve status depends upon consideration of further drilling and metallurgical testing results, and application of economic and technical feasibility factors, such as mining, dewatering, and processing costs. Placer Dome will be reporting the updated 1997 year-end reserves in late February or early March 1998. At the end of 2003, Placer Dome reported proven and probable gold reserves at Pipeline of 12.3 million ounces.

Comment (Commodity): Mercury (Hg) is recovered but more as a pollution abatement measure than for economic reasons.

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References

Reference (Deposit): Geological Society of Nevada 1997 Spring Field Trip: Geology and Ore Deposits of Northeastern Nevada, Special Publication No. 25

Reference (Deposit): Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette.

Reference (Deposit): Geology and Ore Deposits of the American Cordillera, Field Trip Guidebook Compendium of the April 1995 Geological Society of NevadaSymposium; 501 p.

Reference (Deposit): The Nevada Mineral Industry, 1992, Nevada Bureau of Mines and Geology, Special Publication, MI Series

Reference (Deposit): Royal Gold 1994 SEC Form 10K

Reference (Deposit): Foo and others, 1996

Reference (Deposit): Mining Record, Sept. 8, 1993, Howell Publishing Co., Denver, Co

Reference (Deposit): Royal Gold Inc. press release, 12/22/97.

Reference (Deposit): Adella Harding, Elko Daily Free Press Mining Quarterly, Fall 2002.

Reference (Deposit): PLACER DOME, NEWS RELEASE, 9/24/96.

Reference (Deposit): THE MINING RECORD, 12/4/96, P8.

Reference (Deposit): MINING MAGAZINE, VOL., 175, #3, SEPT., 1996, PP. 6, 8, 11, 12, 15.

Reference (Deposit): THE MINING RECORD, VOL., 108, #9, FEB. 26, 1997, PP. 8, 9.

Reference (Deposit): THE MINING RECORD, VOL., 107, #49, 12/04/96, P8.

Reference (Deposit): SOUTHWESTERN PAYDIRT, # 688, OCT., 1996, P4.

Reference (Deposit): SKILLINGS MINING REVIEW, V86, #27, JULY 5, 1997, P12.

Reference (Deposit): RANDOL MINING DIRECTORY, 1994/95, U.S. MINES AND MINING COMPANIES, P 352.

Reference (Deposit): PLACER DOME, 1995 FORM 10-K REPORT, PP. 19, 20.

Reference (Deposit): CORAL GOLD CORPORATION, NEWS RELEASE, OCT, 1996.

Reference (Deposit): RANDOL MINING DIRECTORY,1996/97, U.S. MINES & MINING COMPANIES, PP. 266, 273.

Reference (Deposit): PAY DIRT, #693, MARCH 1997, P12.

Reference (Deposit): THE MINING JOURNAL, VOL., 328, #8420, MARCH 14, 1997, P210.

Reference (Deposit): THE MINING RECORD, VOL., 108, #13, MARCH 26, 1997, P1.

Reference (Deposit): NAM, NORTH AMERICAN MINING, VOL 1, #3, APRIL, 1997, P24.

Reference (Deposit): ENGINEERING AND MINING JOURNAL, 2-97, P. 46-50.

Reference (Deposit): THE RTZ CORP., PLC CRA LIMITED, 1995 ANNUAL REPORT ON FORM 20-F, PP. 16, 17, 29.

Reference (Reserve-Resource): RTZ-CRA, FACT BOOK, 1997, P21.

Reference (Reserve-Resource): RTZ-CRA, 1996 ANNUAL REPORT ON FORM 20-F, PP. 17, 29.

Reference (Reserve-Resource): THE NORTHERN MINER, 6-2-97, P.B1, B6.

Reference (Deposit): THE RTZ COPR. PLC, 1994 ANNUAL REPORT.

Reference (Deposit): PLACER DOME, 1994, 95, "NEWS ABOUT PLACER DOME".

Reference (Deposit): THE MINING RECORD, V106, #14, APRIL 5, 1995, P1.

Reference (Deposit): SKILLINGS MINING REVIEW, OCT 5 1996, P9.

Reference (Reserve-Resource): PLACER DOME, 1994 ANNUAL REPORT, P16..

Reference (Reserve-Resource): AMERICAN MINES HANDBOOK 1996, P195, "CORTEZ MINE", #4-5.

Reference (Deposit): 1995/96, NEVADA MINES DIRECTORY, P16.

Reference (Deposit): THE NORTHERN MINER, JUNE 3, 1996, P B7.

Reference (Deposit): THE MINING RECORD, VOL 107, #39, SEPT. 25, 1996, P3.

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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.