Musgrave Block - Proterozoic Basement

Proterozoic Basement

The Proterozoic of the Musgrave Block is composed of seven main classes of rocks;

• Surficial volcanics of c.1050 to 1080 Ma, both mafic (Mummawarrawarra Basalt) and andesitic to rhyolitic (Tollu, Smoke Hill Volcanics) and the Bentley Supergroup volcanics and sediments of c. 1080 Ma
• Large intrusive caldera type granite intrusive complexes (Palgrave, Skirmish Hill, Smoke Hill), possibly of c. 1050 and likely no older than 1080 Ma
• Partly metamorphosed, rarely dissected c. 1080 Ma granite
• Usually unmetamorphosed, rarely dissected granites of a c. 1050 intrusive suite
• Partly metamorphosed, dissected intrusive rocks of the mafic-ultramafic c. 1080 Ma Giles Complex
• Highly metamorphosed metagranites of the c. 1200 Ma suite
• High-grade crystalline metamorphic basement rocks of c. 1550-1300 Ma age

The Musgrave Block is flanked by several Proterozoic to Palaeozoic sedimentary basins, whose sedimentary history can elucidate the timing of tectonic events in the Musgrave Block post-1080 Ma. These include the Proterozoic Amadeus and Officer Basins.