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Pipeline & South Pipeline Mines

Producer in Lander county in Nevada, United States with commodities Gold, Silver, Mercury
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Alteration
  9. Mineral occurrence model information
  10. Host and associated rocks
  11. Nearby scientific data
  12. Geologic structures
  13. Ore body information
  14. Controls for ore emplacement
  15. Economic information about the deposit and operations
  16. Mining district
  17. Land status
  18. Ownership information
  19. Reserves and resources
  20. Links to other databases
  21. Bibliographic references
  22. General comments
  23. Reporter information

Geologic information

Identification information

Deposit ID 10310340
MRDS ID MP90059
Record type Site
Current site name Pipeline & South Pipeline Mines
Alternate or previous names Cortez Joint Venture Mines, Pipeline Complex, South Pipeline Extension deposit (Crossroads), Crescent Pit
Related records 10048827

Comments on the site identification

  • Record replaces MRDS records #MP90059 and MP90061 and includes all information from the earlier records which should be deleted.

Geographic coordinates

Point of reference Pit
Geographic coordinates: -116.712, 40.247 (WGS84)
Relative position The Pipeline & South Pipeline Mines area is located on the southwest side of Crescent Valley about 100 kilometres southwest of Elko.

Site location context

Political divisions (FIPS codes)

Lander(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Cortez Canyon(quadrangle 1:24,000 scale)

Crescent Valley(quadrangle 1:100,000 scale)

Winnemucca(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Middle Humboldt(hydrologic unit)

Humboldt(hydrologic accounting unit)

Black Rock Desert-Humboldt(hydrologic subregion)

Great Basin(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management NV)

Bureau of Land Management NV BLM(Type of land area)

BLM(Federal land areas administered by BLM)

Geographic areas

Country State County
United States Nevada Lander

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 027N 047E 06 Nevada

Comments on the location information

  • South Pipeline is approximately 500 feet south of the Pipeline deposit. Coordinates are for the center of the pit that includes both deposits.

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Mercury Secondary

Comments on the commodity information

  • Ore Materials: free gold
  • Gangue Materials: quartz iron oxides, pyrite
  • Mercury (Hg) is recovered but more as a pollution abatement measure than for economic reasons.

Materials information

Materials Type of material
Quartz Ore
Pyrite Ore
Gold Gangue

Alteration

  • (Local) 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.

Mineral occurrence model information

Model code 173
USGS model code 26a.1
Deposit model name Sediment-hosted Au
Mark3 model number 17

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate
    Rock unit name Roberts Mountains Formation
    Stratigraphic age (youngest) Early Devonian
    Stratigraphic age (oldest) Wenlock
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Rock type qualifier calcareous
    Rock unit name Roberts Mountains Formation
    Stratigraphic age (youngest) Early Devonian
    Stratigraphic age (oldest) Wenlock
  • Host or associated Host
    Rock type Unconsolidated Deposit > Alluvium
    Stratigraphic age (youngest) Quaternary

Nearby scientific data

Pit (1) -116.712, 40.247
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description range-front fault
Type of structure Regional
Structure description Roberts Mountains thrust fault

Ore body information

  • General form irregular

Controls for ore emplacement

  • Lithology and structure both control ore formation.

Comments on the geologic information

  • 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.

Economic information about the deposit and operations

Operation type Surface
Development status Producer
Commodity type Metallic
Significant Yes
Discovery year 1991
Mining method Open Pit
Year of first production 1996
Plant type Leach
Milling method Heap Leach-Agglomerate-Carbon Column-Merrill-Crowe

Mining district

District name Bullion District
District name Cortez district

Land status

Ownership category BLM Administrative Area
Area name Battle Mountain BLM-administrative district

Ownership information

  • Type Owner-Operator
    Owner Cortez Joint Venture: Placer Dome, Inc.
    Interest 60
    Year 2004
  • Type Owner-Operator
    Owner Cortez Joint Venture: Kennecott Explorations
    Interest 40
    Year 2004
  • Type Owner
    Owner Barrick Gold Corp.
    Interest 100
    Year 2009
    First year 2008

Comments on the production information

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

Reserves and resources

  • Type In-situ
    Estimate year 1996
    Demonstrated 85140000mt ore
    Total resources 85140000mt ore
    Remarks South Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.5 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1996
    Demonstrated 44000000mt ore
    Total resources 44000000mt ore
    Remarks South Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.75 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1996
    Demonstrated 1696000mt ore
    Remarks South Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 5.01 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1996
    Total resources 16692000mt ore
    Remarks South Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 5.45 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1997
    Demonstrated 47808636mt ore
    Remarks South Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.86 g/mt Gold Major 1997
  • Type In-situ
    Estimate year 1997
    Demonstrated 102511876mt ore
    Remarks South Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.58 g/mt Gold Major 1997
  • Type In-situ
    Estimate year 1997
    Demonstrated 54703240mt ore
    Remarks South Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.34 g/mt Gold Major 1997
  • Type In-situ
    Estimate year 1997
    Demonstrated 42700000mt ore
    Remarks South Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1.82 g/mt Gold Major 1997
  • Type In-situ
    Estimate year 1994
    Measured 19210000mt ore
    Demonstrated 19210000mt ore
    Total resources 19210000mt ore
    Remarks Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 4.1 g/mt Gold Major 1994
  • Type In-situ
    Estimate year 1994
    Measured 7533000mt ore
    Demonstrated 7533000mt ore
    Total resources 7533000mt ore
    Remarks Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 1 g/mt Gold Major 1994
  • Type In-situ
    Estimate year 1996
    Demonstrated 32300000mt ore
    Remarks Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 4.15 g/mt Gold Major 1996
  • Type In-situ
    Estimate year 1997
    Demonstrated 36500000mt ore
    Remarks Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 3.63 g/mt Gold Major 1997
  • Type In-situ
    Estimate year 1997
    Demonstrated 82700000mt ore
    Total resources 82700000mt ore
    Remarks Pipeline
    Commodity Subtype Grade units Group Importance Year
    Gold Au 2.7 g/mt Gold Major 1997

Comments on the workings information

  • 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.

Comments on other 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.

  • 6-2-97: IN 1981, THE MILL PROCESS WAS CONVERTED TO A CIL PLANT FROM A STANDARD MERRILL-CROWE PLANT.

Comments on 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.

Reference information

Bibliographic references

  • Deposit

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

  • 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.

  • Deposit

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

  • Deposit

    The Nevada Mineral Industry, 1992, Nevada Bureau of Mines and Geology, Special Publication, MI Series

  • Deposit

    Royal Gold 1994 SEC Form 10K

  • Deposit

    Foo and others, 1996

  • Deposit

    Mining Record, Sept. 8, 1993, Howell Publishing Co., Denver, Co

  • Deposit

    Royal Gold Inc. press release, 12/22/97.

  • Deposit

    Adella Harding, Elko Daily Free Press Mining Quarterly, Fall 2002.

  • Reserve-Resource

    PLACER DOME, 1994 ANNUAL REPORT, P16..

  • Reserve-Resource

    AMERICAN MINES HANDBOOK 1996, P195, "CORTEZ MINE", #4-5.

  • Reserve-Resource

    RTZ-CRA, FACT BOOK, 1997, P21.

  • Reserve-Resource

    RTZ-CRA, 1996 ANNUAL REPORT ON FORM 20-F, PP. 17, 29.

  • Reserve-Resource

    THE NORTHERN MINER, 6-2-97, P.B1, B6.

  • Deposit

    THE RTZ COPR. PLC, 1994 ANNUAL REPORT.

  • Deposit

    PLACER DOME, 1994, 95, "NEWS ABOUT PLACER DOME".

  • Deposit

    THE MINING RECORD, V106, #14, APRIL 5, 1995, P1.

  • Deposit

    1995/96, NEVADA MINES DIRECTORY, P16.

  • Deposit

    THE NORTHERN MINER, JUNE 3, 1996, P B7.

  • Deposit

    THE MINING RECORD, VOL 107, #39, SEPT. 25, 1996, P3.

  • Deposit

    SKILLINGS MINING REVIEW, OCT 5 1996, P9.

  • Deposit

    CORAL GOLD CORPORATION, NEWS RELEASE, OCT, 1996.

  • Deposit

    RANDOL MINING DIRECTORY,1996/97, U.S. MINES & MINING COMPANIES, PP. 266, 273.

  • Deposit

    PAY DIRT, #693, MARCH 1997, P12.

  • Deposit

    THE MINING JOURNAL, VOL., 328, #8420, MARCH 14, 1997, P210.

  • Deposit

    THE MINING RECORD, VOL., 108, #13, MARCH 26, 1997, P1.

  • Deposit

    NAM, NORTH AMERICAN MINING, VOL 1, #3, APRIL, 1997, P24.

  • Deposit

    ENGINEERING AND MINING JOURNAL, 2-97, P. 46-50.

  • Deposit

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

  • Deposit

    PLACER DOME, 1995 FORM 10-K REPORT, PP. 19, 20.

  • Deposit

    RANDOL MINING DIRECTORY, 1994/95, U.S. MINES AND MINING COMPANIES, P 352.

  • Deposit

    SOUTHWESTERN PAYDIRT, # 688, OCT., 1996, P4.

  • Deposit

    THE MINING RECORD, VOL., 107, #49, 12/04/96, P8.

  • Deposit

    THE MINING RECORD, VOL., 108, #9, FEB. 26, 1997, PP. 8, 9.

  • Deposit

    MINING MAGAZINE, VOL., 175, #3, SEPT., 1996, PP. 6, 8, 11, 12, 15.

  • Deposit

    THE MINING RECORD, 12/4/96, P8.

  • Deposit

    PLACER DOME, NEWS RELEASE, 9/24/96.

  • Deposit

    SKILLINGS MINING REVIEW, V86, #27, JULY 5, 1997, P12.

General comments

Subject category Comment text
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.
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.

Reporter information

Type Date Name Affiliation Comment
Reporter 18-AUG-95 Sachiko Tanikawa U.S. Geological Survey
Reporter 10-SEP-97 Buckingham, David A. U.S. Bureau of Mines
Reporter 01-JAN-00 LaPointe, D.D. Nevada Bureau of Mines and Geology
Editor 01-SEP-07 Schruben, Paul G. U.S. Geological Survey Converted from S&A FileMaker format to Oracle. Edit checks on rocks, units, and ages with Geolex search, and other fields.

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Nevada resources

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