The Widgiemooltha mineralisation is controlled by north-northwest trending structures and mainly hosted within basaltic rocks. Alteration assemblages consist of biotite-albite-carbonate and contain finely disseminated sulphides, mostly pyrite. The veining is dominantly quartz-carbonate with minor pyrite. Small aplite dykes, 1 m to 10 m thick, occur at Bass and Hronsky, and minor cherty-pyritic sediments and pegmatitic dykes at Flinders.

Two ore morphologies can be identified at North Widgiemooltha, namely the steeply-dipping tabular lodes such as Bass and Hronsky, and the stacked shallow-dipping reef complexes hosting Flinders, Darlek and to a lesser extent West Oliver.

There is only thin transported overburden in local areas (<3 m). The degree of weathering in the area varies with saprolite (100% weathered sulphides) from 0 to 15 m below the surface, while saprock (a mixture of weathered and unweathered sulphides) occurs down to 50 m depth.

Mine designs included geotechnical imports from Green Geotechnical who reviewed existing pits in the immediate area and fresh diamond drill core. There were recommendations of a series of wall and batter angles for pit designs; the steepest angle was 70°.

Pit designs assume open pit mining using six-wheel articulated trucks that haul on steeper ramps and have a small turning radius.

Mining dilution is factored at 20% for all pits, except the main Flinders pit which was assigned 10% given the greater ore widths. Mining recovery is 95% for all the prospects. A minimum mining width of 2.0 m was adopted. These parameters are considered appropriate by independent consultants for the types of mineralisation observed at Widgiemooltha.

Over the course of FY2019, four open pits were completed (Flinders Main, Bass South 3, West Oliver South and West Oliver North), with three pits in operation at 30 June 2019 (Flinders West, Hronsky and Darlek).

Mining activities ceased late in September 2019 following completion of the Flinders West, Hronsky and Darlek pits.

Standard CIP recovery from cyanide leached gold is the recovery method.