Steeply dipping, east-northeast-striking BIFs are known to occur in three ridges at Weld Range: the North, Central and South Ranges.  The BIFs are interleaved with metabasic rocks that show doleritic and lesser basaltic and gabbroic textures.  The BIFs within the North, Central and South Ranges are referred to as the Madoonga, Lulworth and Wilgie Mia beds, respectively.  Iron mineralisation within the three ranges is not continuous and occurs as 44 distinct iron ore lenses, named W1 to W44. 

The Madoonga deposit contains a steeply south southeast-dipping rock sequence that comprises, from north to south, felsic sedimentary rocks, a 60 to 250 m thick BIF and a 20 to 50 m thick zone of deeply weathered and altered rocks within which the iron mineralisation is hosted.  Sediments and sedimentary rocks lie above an erosional unconformity on the iron mineralisation and deeply weathered rocks.  The sedimentary rocks comprise ferruginous conglomerate and pisolitic gravels that have a thickness of up to 20 m and locally have high Fe grades (>60% Fe).

The Beebyn deposit contains numerous steeply southeast dipping BIFs interlayed with dolerite, of which the most economically important is approximately 40 m thick.    Least altered and unweathered BIFs contain millimetre to centimetre thick bands rich in iron, silica and Fe-silicate and some of the bands are carbonate rich.  These mineralised zones are offset by up to 100 m late sub vertical northwest striking faults.

Mining will occur at two main deposits, namely Beebyn and Madoonga.  The ore will be fragmented at the mine face using conventional Ammonium Nitrate Fuel Oil (ANFO) and controlled blast designs.

Beebyn and Madoonga will be developed as conventional open cut mines.  The proposed operations at Weld Range are expected to have a disturbance footprint of about 4074 ha (40.7 km²), or 18% of the total area occupied by the Weld Range (approximately 22,500 ha (225 km2
)).

The viability of the Project is dependent on both deposits, Beebyn and Madoonga, being mined in parallel.  A staged pit design will allow the deposits to be developed progressively. 

Mining the two deposits together will allow for a degree of blending with higher Beebyn iron ore grades, partially offsetting the lower Madoonga iron ore grades.  Moreover, mining the deposits together avoids infrastructure bottlenecks that could be experienced if each site was required to produce peak production independently.

Weld Range is a Direct Ore Shipping Project.