Australia

Great Cobar Project

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Categories

Overview

Mine TypeUnderground
StagePermitting
Commodities
  • Copper
  • Gold
  • Zinc
  • Lead
  • Silver
Mining Method
  • Longhole stoping
Backfill type ... Lock
Mine Life... Lock
SnapshotThe Great Cobar Project is new satellite base metals and a gold underground mine which would deliver ore to the Peak Mine process plant.

The Great Cobar Project's maiden Ore Reserve was released in January 2022. During FY2023, Ore Reserve tonnage increased by 43%.

Regulatory approvals for the construction of an exploration decline to the Great Cobar project have been granted. Regulatory approvals for production mining at Great Cobar are in progress.
Related AssetPeak

Owners

SourceSource
CompanyInterestOwnership
Aurelia Metals Ltd. 100 % Indirect
Peak Gold Mines Pty Ltd. (operator) 100 % Direct
Peak Gold Mines Pty Ltd (PGM) (a subsidiary of Aurelia Metals) owns and operates the Peak Mine which includes Great Cobar underground mine.

Contractors

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Deposit type

  • Vein / narrow vein
  • Breccia pipe / Stockwork

Summary:

The deposits fall under the group of epigenetic “Cobar Style” mineralisation and are controlled structurally by major fault zones (Rookery Fault System) and subsequent spurs and splays. The faults are within the Devonian-Nurri Group of sedimentary units displaying lower green schist facies alteration. The economic minerals are contained within quartz stockworks and breccias. The breccia matrix are combinations of quartz, sediment, rhyolite and sulphide. The deposits are often polymetallic with copper, gold, zinc, lead and silver occurring in parallel lenses to the fault zones within the PGM leases.

The Great Cobar deposit is located in the northern part of the Cobar Gold Field on the eastern margin of the Cobar basin. The deposit is localised within the sub-vertical dipping Great Cobar Fault which is located wholly within siltstones and shales of the Great Cobar Slate. The deposit has a planar-shaped geometry dipping sub parallel to the regional cleavage and plunging steeply north parallel to a strong stretching lineation. The deposit is approximately 200m long, 20-30m wide and extends over a vertical distance of at least 1,200m.

The copper mineralisation is associated with a zone of intense quartz veining, magnetite brecciation and chlorite-stilpnomelane alteration. Copper is contained within chalcopyrite and shows a close association with pyrrhotite.

Significant lead and zinc intersections have been recorded from drilling. These intersections form a lens immediately west of the copper mineralisation referred to as the Great Cobar Lead (GCL) lens. The lens typically consists of galena and sphalerite with varying proportions of pyrite and pyrrhotite.

Geology and Mineralization
The main ore bodies of the Cobar field are known for their great vertical persistence. Their depth may be many times the horizontal length along the shear strike. Their length in turn is usually greater than the worked width. The ore bodies have the shape of a flattened pipe or carrot.

The Great Cobar deposit occurs in an anastomosing shear zone within the beds of the Cobar Slate formation (Cobar Group). The strike of the mineralized zone is approximately north-south. The dip of the lodes is almost vertical, with local variation favouring east or west in parts, resembling pinch, and swell. The pitch is steeply to the north.

The lead/zinc lode on the western edge of the shear can vary in thickness considerably, from centimetre scale wisps to metre scale massive sulphide.The lead/zinc is usually a marker indicating the end of the copper-gold primary target zone.

The copper zone broadly extends eastward from the lead/zinc horizon. An eastern edge does not have a well-defined or sharp contact. The mineralisation can consist of zones of massive mineralisation or stock work space veins. The assemblage consists mainly of chalcopyrite-magnetite-pyrrhotite. Gangue includes quartz, chlorite, and stilpnomelane.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

CommodityProductUnitsLOM
Copper Metal in concentrate kt 66
Gold Metal in conc./ doré koz 92

Operational metrics

Metrics
Annual ore mining rate  ....  Subscribe
* According to 2023 study.

Production Costs

Commodity production costs have not been reported.

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNamePhoneEmailProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Dec 1, 2023
....................... Subscription required ....................... Subscription required ........... Subscription required ........... Subscription required Dec 1, 2023
....................... Subscription required ....................... Subscription required Subscription required Dec 1, 2023

Aerial view:

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