Petermann Orogeny - Economic Geology

Economic Geology

The Petermann Orogeny exposes deep crustal roots of the previous Musgrave Orogen and lkely parts of several poorly exposed Proterozoic orogenic belts and igneous provinces. As such, the rocks of the Petermann Orogen are considered prospective territory for mineral exploration.

The history of mineral exploration in the Petermann Orogen extends back to the last half of the 19th century, with a series of prospectors and exploring pioneers transiting the area. Most famously was Lasseter, who allegedly found Lasseter's Reef, a near-mythical gold lode of such richness and scale that it has fired imaginations for over a century, but remains undiscovered.

In the mid and late 20th century, government missionaries brought to the indigenous Aborigines of the area European law, European culture and the concept of salaried work, previously unknown to the hunter-gatherer inhabitants. In order to provide work, subsidised exploration was undertaken by the Western Mining Corporation, resulting in the discovery of podiform copper at Warburton Range, and eventually the Wingelinna nickel laterite resource.

The advent of the Mabo Decision and land rights movements has seen aboriginal land rights improved, with the result that they now control access to land and exploration tenements. This has created uncertainty about tenure and land access for mineral exploration.

There are three main known forms of mineralisation in the Petermann Orogen;

• Magmatic Ni-Cu-PGE at the undeveloped Nebo-Babel Deposit, found by Western Mining Corporation, and now owned by BHP Billiton.
• Podiform copper hosted in sheared basalts in the Warburton Ranges, near Warburton, Western Australia, worked in the 1960s and 1970s.
• Laterite nickel, primarily at Wingelinna.

Exploration for Olympic Dam lookalikes and for magmatic nickel copper mineralisation is continuing.