Mineralisation is associated with quartz veining and alteration focused within sub volcanic basaltic-andesite sills and adjacent volcaniclastic sediments. The deposits appear to have formed as the result of a rheological contrast between the porphyritic sub-volcanic sills and the surrounding volcaniclastic sediments, with the sills showing brittle fracture and the sediments ductile deformation, and have many similarities to well documented orogenic -lodestyle gold deposits.

Mineralisation at Wyoming One is developed within a number of different zones:

- porphyry – mineralisation hosted by a quartz stockwork within the carapace of a subvolcanic sill with dimensions roughly 60m x 150m. High grade mineralisation is developed along the eastern contact of the zone (‘contact’ zone);

- hangingwall – a linear zone of mineralisation situated approximately 30m to hangingwall of the ‘porphyry’ mineralisation and hosted within silicified and brecciated carbonaceous mudstone. This zone is interpreted to fold around the northern end of the porphyry (northern zone);

- ‘376’ – east west zone of high grade mineralisation developed at the northern contact
of the porphyry. Interpreted to be a bounding structure and primary fluid conduit. Other high grade east-west structures e.g. ‘831’ appear to be developed en-echelon and to the south of the ‘376’ zone;

- footwall – a low grade zone located in a similar stratigraphic position to the hangingwall zone but footwall to the porphyry.

Mineralisation at Caloma Two is developed within a series of ‘quartz lodes’ which dip north at flat to moderate angles and hosted dominantly within the sub-volcanic sills. Mineralisation is also developed along a sediment contact zone which appears to be a potential linking structure with the Caloma mineralisation to the north. There is also evidence for the development of an inverted saddle reef at depth. The lodes are cross cut by a number of post mineralisation dolerite dykes.

Tomingley Gold Operations (TGO) is based on four gold deposits near Tomingley (Wyoming One, Wyoming Three, Caloma One and Caloma Two). Mining at Wyoming Three completed in 2016, and at Caloma One in August 2017.

A significant drilling program continues targeting strike extensions and in-fill areas for the potential underground operation below the Wyoming One pit with the aim of lifting the gold ounces per vertical metre in any future designs. The program is expected to be completed around October 2017, at which time the geological models will be updated and a mine plan evaluated for development.

The Tomingley Gold Operations processing plant utilises two stage crushing, single stage grinding and a gravity/CIL gold recovery circuit. The plant has a designated throughput of 1.25mtpa of oxide ore and 1.0mtpa of fresh (sulphide) ore. The plant has been operational since February 2014.