Many settlements were built in areas that were on dry land at the end of the Ice Age, when sea levels were lower, but sank as the sea rose, according to a study published in the journal PLOS ONE on Wednesday.
Australia’s coastline is 100 miles offshore now, says a team of researchers led by archaeologist Jonathan Benjamin of Flinders University in Adelaide, so many ancient sites are likely to be underwater.
The scientists sent divers to explore possible locations and also used many techniques, such as aerial and submarine remote sensing.
They found two locations in northwestern Australia. The first, on the Cape Bruguieres Channel, contained objects at least 7,000 years old. In the second location, the Flying Foam Passage, they found a unique artifact of 8,500 years old.
Many of the objects had marine life growing on them, but the team was able to locate a number of processed stone tools, including two possible grinding stones.
The findings show that these exploration techniques are useful for detecting underwater archeological sites, said the authors, who hope they can be used to systematically retrieve and explore ancient objects.
The group also urged the Australian government to enact legislation that would protect and manage indigenous areas along the coastline.
“Managing, exploring and understanding the archeology of the Australian mainland in collaboration with traditional owners and guardians of the Aborigines and Torres Strait Islander Islands is one of the latest frontiers in Australian archeology,” Benjamin said.
“Our results represent the first step in a journey of discovery to explore the potential of archeology on continental shelves that can fill a large gap in human history on the continent,” he added.
In 2016, a genomic study revealed that Aboriginal Australians are the oldest known civilization on Earth, with ancestors dating back about 75,000 years.
The findings show that the Aborigines deviated from the Eurasian ones 57,000 years ago, after a single exit from Africa about 75,000 years ago.
The data may show that Indigenous Australians came to the continent as early as 31,000 years ago.