Australian aboriginal culture, the world's oldest continuous civilisation, could have started 18,000 years earlier than previously thought.
Axeheads and grinding stones discovered in a cave in Australia's far north suggest humans arrived on the continent about 65,000 years ago. This pushes back a previous scientific consensus of evidence of humans at 47,000 years ago.
A technique called luminescence dating aged the ancient tools, found at the bottom of a cliff on the edge of a sandy savannah plain about 300 kilometres east of Darwin.
Scientists believed humans first left Africa between 100,000 and 60,000 years ago, said Dr Chris Clarkson, the study's lead author.
"Because Australia sits at the end of this migration route we can now use this as a benchmark, and use it to say that people must have left Africa earlier than this."
Dr Clarkson's paper was published in the journal Nature, which last month revealed that fossils found in Morocco were 300,000 years old – 100,000 years older than any other human remains found before.
The Australian study used radio-carbon dating, which reaches its limits at about 50,000 years, and luminescence, which used laser beams to date 28,500 individual grains of sand from the site, which sits on a Rio Tinto uranium mining lease in the Northern Territory.
"Previous excavations didn't have the access to the dating methods that we do these days to actually confirm that the deposits and the archaeology really were that old," said Andy Herries, an expert in palaeoscience and geoarchaeology at La Trobe University in Melbourne, who was not part of the study.
"The problem previously was that there were some old dates and stones but it was just a couple of them, whereas this research shows a significant occupation."
Reuters