The Braemar Iron Formation (The Braemar) is an emerging iron ore region in northeast South Australia and far western New South Wales. It consists of a series of alternating bedded, tillitic, and interbedded magnetite units that represent cycles of glacial advances and retreats.
The Braemar was discovered and named in the early 1900s by famed Australian geologist and explorer, Sir Douglas Mawson, whilst mapping the geology of the Adelaide Geosyncline in the Barrier Ranges.
In response to the discovery and development of the Pilbara in Western Australia, iron ore potential of the Braemar was investigated by the South Australian Government in the 1960s. Razorback Ridge was selected as the location to further explore because it is the largest known outcropping of the formation. Geological mapping, surface sampling, drilling, adit development, and metallurgical testing at that time identified the significance of the mineralisation.
Braemar ore deposits are unusually soft and only slightly abrasive when compared to typical taconite or BIF deposits. The Braemar deposits therefore offer competitive grinding cost advantages.
Braemar magnetite grains occur in a matrix of soft siltstone and shale and break readily along grain boundaries. In typical BIF and taconite deposits, the magnetite is inter-grown with a hard quartz-rich matrix and breakage is more often across grain boundaries.