Ancient rocks in remote Western Australia have revealed how the tectonic plates of the Australian continent were formed, a study has found.
Uranium-lead dating of rock minerals revealed the rugged landscape of the East Pilbara was formed 3.6 to 3.4 billion years ago, when the earth's mantle was at its hottest.
Lead researcher Daniel Wiemer, from the University of WA, said the study was based on the oldest parts of the earth's crust to be found in the region.
It found the dome-shaped rocks were formed when extreme temperatures caused plumes of granite to rise above layers of dense basalt.
Known as gravitational overturn, the rocks underwent the process at least three times in 100-million-year cycles to ultimately emerge as a stable continent able to support tectonic plates.
By recreating the event, researchers were able to witness how plates were formed 3.2 billion years ago.
The study could lead to greater understanding of geographical events, and how planets evolve, Dr Wiemer said.
