The Castle Hill Mineral Resource comprises four deposits from south to north: Wadi, Mick Adam, Outridge and Kiora.

The principal lithology to host gold mineralisation at Mick Adams-Kiora and Wadi (Castle Hill Stage 1) is the Kintore Tonalite a large intrusive granitoid of granodioritic composition. The tonalite intrudes a sequence of basaltic and ultramafic rocks to the east and west. The elliptical Kintore Tonalite attenuates to the south to form very long narrow (80m wide in plan) intrusion which hosts the Mick Adams and Wadi gold mineralisation and a dyke swarm to the south-east which hosts the Outridge and Kiora gold mineralisation. Gold mineralisation is also hosted along the eastern margin of the main body of the tonalite at Wookie and Picante. Gold mineralisation in this area is hosted within the tonalite and within the flanking mafic/ultramafic sequence. The Lady Alice gold mineralisation is associated with a fault array hosted entirely within the bulk of the tonalite intrusive. The Lady Alice fault array coincides with the boundary between de-magnetised tonalite to the east and magnetised tonalite to the west.

Vertical vein arrays and kinematic indicators at Mick Adams and Kiora show the primary deformation at Castle Hill was extension with an east block down (sinistral normal) sense of movement, suggesting emplacement of the tonalite coincided with the beginning of an extensional doming event and the start of basin formation.

Mick A ........

Mining at Castle Hill will use a conventional drill and blast, truck and excavator open pit operation with 5-10m high blasting benches mined in two or four 2.5m flitches. The Castle Hill Ore Reserve estimate includes factors for ore loss and dilution. Waste material is classified as material below the marginal cut-off grade (0.50g/t Au) and will be transported to the waste storage facility. Mineralised waste between 0.50 and 0.85g/t gold is stockpiled separately and may be processed pending economic evaluation. Ore is classified as material greater than the marginal cutoff grade (0.85g/t Au) and will be taken to the ROM pad then hauled by road train to the Mungari plant for processing.

Mining dilution applied to ore mined on each bench is 15.0% at zero grade. This factor is higher than other deposits at Mungari (usually 5-10%) due to the small sub-block size in the geological model which will incur external dilution during mining.

Mining recovery of ore on each bench is applied as 99.0%, consistent with other deposits at Mungari based on actual performance at White Foil.

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