The Nifty copper deposit is a sediment hosted copper deposit hosted within the Neoproterozoic sub greenschist facies of the Paterson Orogen, immediately to the east of the Archaean Pilbara Craton.

Copper mineralisation occurred/s as both supergene oxide, sulphide, and transitional mineralisation to a depth of approximately 300m and as stratabound hypogene sulphides hosted by carbonaceous and dolomitic shales, principally within the Nifty carbonate member, to a depth of approximately 600m. The mineralisation is a structurally controlled, chalcopyrite-quartz-dolomite replacement of carbonaceous and dolomitic shale within a folded sequence. The copper mineralisation is largely confined to the northern limb and keel of a significant syncline.

Weathering has altered the mineralisation to a depth of about 200m and therefore three main styles of copper mineralisation occur at Nifty:
1. Oxide dominated mineralisation consisting of malachite, azurite, cuprite, and native copper which extends to depths of up to 100m below the surface.
2. Supergene secondary sulphide mineralisation occurs overlying the base of oxidation. This style of mineralisation is dominated by chalcocite and occurs typically between 100m and 200m below the surface.
3. Primary sulphides occur in quartz-dolomite altered carbonates and shales. The primary copper mineral is chalcopyrite with minor covellite and bornite. Pyrite is a common gangue mineral but only occurs with chalcopy ........

Open pit mining operations are planned to be re-established to provide heap leachable ores to the redeveloped existing heap leach pad. The original project commenced with open pit mining in 1993 and was focused on the relatively high-grade part of the oxide mineralisation but closed in 2006 when open pit economics became marginal and site focus was on the large and rapidly developing underground sulphide operation.

The proposed mining sequence is best described as dividing the open pit into east and west cutbacks. The eastern cutback will be developed first to access higher grade ore near surface and will encroach into the influence of the existing underground subsidence zone. Further discrete phases and cutbacks will need to be developed in such a manner as to deal with any geotechnical stability issues in the subsidence zone to re-establish a stable berm batter configuration.

The optimum open pit shell is based on the maximum un-discounted operating cashflow which reached a depth of 10,085mRL or approximately 225m below surface.

The overall slope angles within the proposed pit will vary between 30 – 38 degrees, similar to the historic open pit and reviews of the available structural and rock mass data indicates inter-ramp angles of up to 50 degrees may be possible within certain domains of the final excavation.

The planned operating areas are large enough to support two mining fleets directing waste and ore to distinctly separate facilities.

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