The majority of ASG’s tenements stretch down the Pilbara in an area approximately 320 kilometres southwest of Karratha, or 170 kilometres southeast of Onslow (see map).

The tenements are located on the western edge of the Bangemall Basin, which is a mobile belt that separates the Pilbara and Yilgarn Blocks.

The older element (Late Archaean to Early Proterozoic; 2800 – 2500 Ma) comprises sediments and volcanics of the Mount Bruce Supergroup. These overlie stable Archaean granite-greenstone basement of the southern Pilbara Block. The younger element is termed the Capricorn Orogen and consists of trough and shelf sequences deposited in the Ashburton Trough and Nabberu Basin.