Agnew gold mine - Asset fundamentals

Asset fundamentals

General location

 

Agnew is situated at latitude 27° 55' S, longitude 120° 42' E in the Norseman-Wiluna Greenstone Belt. It is located 23km west of the town of Leinster in Western Australia, which is 375km north of Kalgoorlie and approximately 870km north-east of Perth. Well-established power, access roads and supporting infrastructure are in place.

Licence status and holdings

 

The Agnew Gold Mining Company Proprietary Limited (AGMC), ACN 098-385-883, was incorporated in Australia in 2001 as the legal entity holding and conducting mining activity on the Agnew mineral leases. The Gold Fields Limited Group holds 100% of the issued shares of AGMC through its 100% holding in the issued shares of Orogen Holding (BVI) Limited. Agnew controls exploration and mineral rights over a total area of 72,236ha (total of granted, inclusive of miscellaneous and non-managed tenements) and has security of tenure for all current exploration and mining leases that contribute to future Mineral Reserves.

Operational infrastructure

 

Agnew currently operates two underground mines, Waroonga and New Holland. At Waroonga, ore is sourced from the Kim South, FBH and Main North lodes that are accessed via declines. New Holland mining occurs in four primary areas: Genesis, New Holland, Cinderella and Sheba. These are accessed via declines. There are also centralised administrative offices, as well as engineering workshops at both Waroonga and New Holland and one active CIP processing plant (1.3Mtpa capacity).

Climate

 

No extreme climate conditions are experienced that may affect mining operations.

Local geology and deposit type

 

Agnew gold mine is situated in the northern portion of the Norseman-Wiluna Greenstone Belt of the Yilgarn Craton, Western Australia. Locally, the Belt comprises a sequence of mafic to ultramafic volcanics and associated interflow sediments, which have been folded to form the Lawlers Anticline. The Lawlers Anticline plunges in a northerly direction at approximately 30°. The core of the anticline has been intruded by granodiorite, which in turn has been intruded by late stage leucogranite.

The mafic and ultramafic volcanics of the Lawlers Anticline are unconformably overlain by a sequence of clastic sediments comprising the Scotty Creek Formation. The sedimentary rocks have been metamorphosed to lower greenschist facies and comprise conglomerates and very fine to very coarse-grained pebbly sandstones and siltstones.

The Agnew deposits are broadly hosted by the intersections between various structures and the relative stratigraphy. Gold mineralisation largely occurs in quartz veins within the sedimentary units of the Scotty Creek Formation.

Orogenic greenstone gold deposits are hosted in a number of different styles of lodes. Although all of the Agnew deposits broadly occur at the intersections between structures and stratigraphy, there are subtle differences in alteration and mineralisation, which are controlled in part by the local host rock chemistry.

LoM

Extensional and brownfields exploration continues, which could increase the LoM given the modelled endowment potential and under explored sections of the tenements. It is estimated that the current Mineral Reserves will be depleted in 2021 (four years).

Environmental, health and safety

 

Agnew continues to be certified to OHSAS18001 and ISO 14001. During 2014, the New Holland operations were amalgamated under these certifications.

The mine was recertified compliant with the International Cyanide Management Code (ICMC) in September 2016.