The Nullagine deposits (Golden Eagle, Camel Creek, Five Mile, Golden Gate Underground, Bartons Underground, Twenty Mile Sandy, Agate, Angela, All Nations, Anne De Vidia, Au81, Au81 West, Bartons Open Pit and Underground, Billjim South, Bow Bells, Buzzard, Condor, Condor North-West, Crossing, Crow, D Reef, Falcon, Gambols Hill, Golden Eagle, Golden Gate (ABC Reef-Harrier, D Reef, Condor, Crow & G Reef), Hopetoun-Endeavour, Hut, Junction, Little Annie, Little Wonder, Majuba, Mundalla, Mustang, Otways, Redbeard, Roscoes Reward, Round Hill, Shearers and Shearers North) are structurally controlled, sediment hosted, lode Au style of deposit. They are all situated in the Mosquito Creek Basin that consists predominantly of Archean aged, turbidite sequences of sandstones, siltstones, shale and conglomerate units.

- Agate – Several stacked lodes striking over 300 metres trend North-north-east.
- All Nations -The deposit has an overall north-south trend and has been drilled over some 750m of strike length.
- Angela – Several stacked lodes with an overall North-East trend strike over a distance of 350 metres and dip around 65 degrees to the north. Mineralisation extends to a depth of 100 metres below the surface.
- Anne de Vidia – Two multiple zones of mineralisation strike east-north-east and dip steeply to the north-north-west and north- north-east and occur over a strike length of approximately 545 metres.
- Au81 -Mineralisation strikes north-south, dips 70 to 80 degrees to the west and extends for 240m.
- Au81 West - The deposit consists of a main lode that has a strike length of over 800 metres and dips at about 60 degrees west and strikes at around 015 degrees. The true thickness of the main lode varies in thickness from 2 to 5 metres.
- Bow Bells – Two different trends of mineralisation containing multiple lodes trend almost east-west and northwest. This covers a strike of 350 metres and continue to a depth of 85 metres below the surface.
- Crossing –Multiple stacked lodes with a bearing of ~010 dipping 75 degrees to the west. The deposit has a strike length over 350m.
- Falcon - Mineralisation has a length of 260m and a nominal plan width of three metres. This deposit has been defined to 75 metres below the surface.
- Gambols Hill – Multiple stacked lodes trend over a distance of 860 metres in a north-east direction steeply dipping to the west.
- Golden Eagle -The main lode trends north- east, dips moderately to the north-west with a strike length of 1,900m and plan thickness 18m. The mineralisation has been defined to a depth of 230m below the surface.
- Hopetoun-Endeavour – is a broadly NE- striking, 2.25km mineralised fault/shear corridor. It is a steeply SE-dipping mineralised shear that outcrops in the order of 3-5 metres in thickness.
- Hut – Nine parallel, north-east trending and moderately dipping lodes over a strike length of 200m, with mineralisation tested to a depth of 100m.
- Junction -Mineralisation is comprised of several lodes that form continuous mineralisation over a strike length of 180m. Mineralisation remains open to the west-north-west.
- Little Wonder - The mineralisation dips steeply to the south and varies in plan width from four to twelve metres.
- Majuba Hill - Eight parallel, north-east trending and westerly steeply dipping lodes over a strike length of 500m, with mineralisation tested to a depth of 60m.
- Mundulla – contains a north south, north-west and north-east trending zone. These zones have a strike length of around 300 metres. Mineralisation - 110 metres.
- Mustang – A north east trending lode with ancillary lodes. Mineralisation extends to depth of 55 metres.
- Otways -The main lode at Otways trends east- north-east and dips steeply to the south, over a strike length of 950m.
- Red Beard - The outcropping quartz veins are mineralised and this continues to a current vertical interpreted depth of 80m. The lodes vary from near vertical to a dip of -75° and strike due westeast over a strike extent of 2km. The main continuous lode (Domain 1) strikes over a length of 490m.
- Roscoes Reward -The deposit has a north-west trending, steeply south-west dipping geometry that is discontinuously mineralised over a strike length of 850m.
- Round Hill -there are two main orientations to the lodes. The first is defined over 120m of strike and the second is defined over 40m of strike.
- Shearers -The deposit trends north-south, dips steeply to the west and extends over a strike length of 750m with an average plan width of 12m, to a depth of 110m below the surface.
- Shearers North - Three main lodes of mineralisation have been interpreted at the deposit, striking NE at approximately 32° over a strike length of 600m.
- Bartons Underground – The main lode is mineralised over a strike length of 1,000 m; the mineralisation plan widths are highly variable, typically ranging from 0.1 m to 4.5 m.

Golden Gate:
- ABC Reef. The main lode is mineralised over a strike length of 300 m and 300 m down dip, typically ranging from 0.3 to 5 m.
- D Reef. The main lode is mineralised over 250 m along strike and 230 m down dip (from surface), typically ranging from 0.3 m to 2.5 m.
- Harrier. One single mineralised lode, trending north-west and dipping steeply to the north-east. Harrier was located along strike and north-west of the ABC mineralisation and extends over 80 m along strike and 65 m down dip (from surface), with plan widths being highly variable, typically ranging from 0.5 to 4 m.
- Crow. The two minor lodes are located approximately 80 m to the south-west of the Crow main lode. Continuity of the main lode is 170 m along strike and 80 m down dip (from surface) whilst the minor lodes are continuous over 50 m along strike and 60 m down dip.
- Condor and Condor North-West. Condor includes six mineralised lodes with mineralisation varying from 30 m to 90 m along strike and 50 m to 100 m down dip. Condor North-West comprises six mineralised lodes with continuity varying from 20 m to 80 m along strike and 30 m to 90 m down dip, typically ranging from 0.6 m to 3.0 m.
- G Reef. Three narrow sub-parallel mineralised lodes, trending north-north-west and dipping steeply to the south-east.

Open Pit
The mining method is conventional drill and blast and load and haul with an excavator and large open pit mining equipment. This is considered to be appropriate for the style of mineralisation being exploited and is applied to many similar type operations in Western Australia.

A 10% gradient and 14 m width (including safety windrow) is used in most in-pit ramp designs. At the base of some pits and in the smaller pits, a 14% gradient and 9m ramp has been utilised.

Geotechnical and hydrogeological recommendations have been applied during pit optimisation and incorporated in designs with ongoing reviews. Mining dilution and ore loss factors have been applied during pit optimisations and hence are considered in the Ore Reserves estimates.

Underground
The mining method for is the “Homestead Method” a minor refinement to the modified Avoca method ustilised extensively within Western Australia. This is considered to be appropriate for the style of mineralisation being exploited, the geothechnical conditions encountered and expected and is applied to many similar type operations in Western Australia.

A 14% gradient 5.5m wide, 5.5m high decline is used as the primary access with smaller drive sizes utilised for non-truck access locations.

Production from Nullagine has traditionally been sourced from open pits the AU81, Gambols Hill, Golden Eagle South, Mustang, Red Beard and Round Hill open pits during 2018, however mining commenced at the Company’s first-ever underground mine at Bartons in late 2018 and a second underground mine is scheduled to be developed at Golden Gate in Q3 2019.

The existing 1.5 Mtpa nameplate ore processing facility and infrastructure consists principally of a primary crusher, SAG mill, gravity circuit and carbon-in-leach (CIL) tankage and will be utilised for the processing of the Ore Reserves. Metallurgical recovery factors are based on metallurgical tests and ongoing actual plant recovery reconciliation factors. For the Oxide Pit reserves, Recovery factors range from 70% to 95% and vary depending on particular areas in each pit and deposit. These factors have been assumed in the pit optimisation and Ore Reserves estimates. For the Sulphide Pit reserves, an improvement on these recoveries (some of which are less than 50%) has been applied. All recoveries have been applied on a pit by pit basis and dependant on the planned processing regime.