The Pilbara region comprises a large part of the ancient continental shield of Western Australia which is comprised of both Proterozoic and Archaean rocks. The Pilbara is overlain by the Proterozoics deposited in the Hamersley and Bangernall Provinces.

The BIF is a member of the ~620 m thick Brockman Iron Formation which makes up part of the 2.63 2.45 Ga Hamersley Group. The Hamersley Group comprises almost 2.5 km of consecutive sedimentary and volcanic rocks located within the ca. 80,000 km2 Hamersley Province of the Pilbara craton in North West Australia, approximately 1100 km north of Perth. In the lower part, it consists of dolomite, shale and BIF, while the upper part consists of dolerite, various lava types and BIF with minor amounts of tuffs and shales. Underlying the Hamersley Group, is the 2.78–2.63 Ga Fortescue Group, which consists of flood basalts and rhyolites. These volcanics were laid down on the uplifted and eroded Pilbara block. This volcanic succession may contain remnants of a Large Igneous Province (LIP).

The Brockman Iron Formation ofthe Hamersley Group is divided into four sub-lithostratigraphic units, namely the lowermost Dales Gorge Member (BIF), the Whaleback Shale Member, the Joffre Member (BIF), and the uppermost Yandicoogina Shale Member. After deposition, these laterally extensive BIF have all experienced minor folding and basinal uplift along with low-grade regional metamorphism – from burial prehnite–pumpellyite facies to greenschist facies.

General consensus exists regarding the depositional model of the Brockman Iron Formation. According to this model, the succession was deposited on a large, stable, and clastic-starved, continental platform, which was influenced by episodic inputs of fine-grained tuffaceous detritus.

Development of this Mineral Resource assumes mining using standard Rio Tinto Iron Ore equipment and methods similar to other Rio Tinto Iron Ore operations. The assumed mining method is conventional truck and shovel, open pit mining at an appropriate bench height. Mining practices will include grade control utilising blast hole data.

There are two existing dry crush and screen processing facilities and one existing wet desliming processing facility to which Brockman Syncline 2 – East Detrital ore could be fed. Product prediction regressions for both dry and wet processing routes are assigned to the designated domains, based on the most appropriate available metallurgical data generated from PQ-3 cores, WDC, winzes and production data.

The dry plants crush and screen the ore into dry lump and fines products.

The wet desliming plant scrubs, screens and deslimes the ore to produce washed lump and fines products. The plant was commissioned in early 2015.