There are two mining areas in the Durkin North mine plan, being the D1/D2 area and the D3/D5 area. The D1/D2 area strikes predominantly east-west with a strike length of ~550m, extending from ~-85mRL (~420 mbs) to -260mRL (175m extent). This area gently plunges to the north resulting in a long strike over a relatively small vertical extent. The orebody in D1/D2 is generally narrow (1-3m), with one main lode and a small hangingwall splay in the southern area. The orebody dips to the north, with dips ranging from relatively shallow dipping (down to 45° in parts) up to 75°. The D3/D5 area strikes southeast/northwest with a strike length of ~380 m, extending from -270mRL to -450mRL (180 m extent). The plunge in this area tends to vertical. Dips are generally steeper than D1/D2, ranging from 65-80° to the north-east. The D3/D5 area contains several closely spaced economically extractable lodes in parallel, with widths 1-3m.

The Long Mineral Resource generally strikes northwest-southeast. The Mineral Resource is spread out over an extensive area. Ore pod strike lengths are variable, ranging from 20-30m to ~500m. Some areas dip steeply and continuously to the north-east at approximately 70-80°, while other ore pods are flat dipping at 15-25°. The orebody is generally less than 2m thick.

The Durkin North mine is planned to be accessed both through the existing Long mine and the existing Otter mine. Both mines are accessible and require minimal rehabilitation. The Durkin North access decline will be developed from both sides and will connect Long and Otter when broken through. The Long designs are all located within the existing Long capital development. Long orebodies will initially be accessed through the Long-Victor portal. Once the Durkin decline has broken through, all access will be via the Otter portal, as this provides a shorter haul distance than the Long-Victor portal with additional ventilation benefits.

Based on the orebody spatial and geotechnical characteristics, the primary mining method proposed is bottom-up longitudinal longhole stoping (LHS) with modified Avoca assuming cemented rockfill (CRF). This mining method requires minimal capital and development and provides void support for dilution mitigation.

Vertical sub-level intervals are 14-16m floor-to-floor, allowing good drill and blast control. Areas without top access (i.e. crown stopes or levels directly beneath sill pillars) will be mined using conventional longhole open stoping, retaining in-situ pillars for support. Maximum open stope strike lengths of 20m have been applied based on geotechnical studies. Slots to open stoping spans have been designed assuming handheld development methods. Subsequently mined stopes in filled levels will be fired against fresh CRF w ........

- subscription is required.