The Hamersley Range is a mountainous region of the Pilbara region of Western Australia. The range was named on 12 June 1861 by explorer Francis Thomas Gregory after Edward Hamersley, a prominent promoter of his exploration expedition to the northwest. The range is one of the oldest mountain ranges on Earth and primarily consists of ancient rock formations, including banded iron formations (BIFs), that are about 2.5 billion years old. The Pilbara Craton, which underlies the Hamersley Range, dates back to around 3.4 billion years, but the range itself is younger than that. The deformation that began uplift of the region and created the tightly folded rocks of the range began around 2.2 billion years ago, during the Ophthalmia Orogeny. This would make it approximately the 6th oldest mountain range in the world. Karijini National Park (formerly known as Hamersley Range National Park) lies within the range.

History

The traditional Aboriginal owners of the area that the range runs through are the Puutu Kunti Kurrama and Pinikura peoples. In 1999 a small range within the Hamersley was named the Hancock Range after the Hancock family, who were pioneers in the area. The Hancock range is east of Karijini National Park in a region of broad valleys and peaks that rise to almost 1200 m. The Hancock Range is close to Mulga Downs Station, a property owned by the Hancock family and where Lang Hancock is buried.

Geography

The range runs from the Fortescue River in the northeast, 460 km to the south. The range contains Western Australia's highest point, Mount Meharry, which reaches approximately 1249 m AHD. There are many extensively eroded gorges, such as Wittenoom Gorge. The twenty highest peaks in Western Australia are in the Hamersley Range. Peaks in the range include Mount Bruce (1234 m), Mount Nameless/Jarndunmunha (1115 m), Mount Reeder Nichols (1109 m), Mount Samson (1107 m), Mount Truchanas (1148 m) and Mount Tom Price (775 m). Karijini National Park (formerly Hamersley National Park), one of Australia's largest national parks, is centred in the range.

Mining

The range contains large deposits of iron ore, producing a large proportion of Australia's iron ore exports. It is predominately associated with banded iron formation. Western Australia's major iron producers have mines, communities and railways that occur along the range. Rio Tinto operates several iron ore mines within the range, including Mount Tom Price, Marandoo, Brockman, Channar, West Angelas, Mesa A mine, and Paraburdoo. Over 100 million tonnes of iron ore is removed from the range every year. Existence of crocidolite (blue asbestos) in the Hamersley Range has been known since 1915. In 1917 crocidolite was discovered at Wittenoom, it was mined from the 1930s and was discontinued in 1966 because of unprofitable production costs. Wittenoom was Australia's only blue asbestos mining town.

Juukan Gorge

A cave in Juukan Gorge, about 60 km from Mt Tom Price, was one of the oldest in the western Pilbara region, and the only inland site in Australia to show signs of continuous human occupation through the Ice Age. The cave was destroyed by Rio Tinto along with another Aboriginal sacred site on 23 May 2020 as part of their expansion of the Brockman 4 mine.