Karnatukul (Australie) : Humans braved hostile desert thousands of years earlier than thought

April Reese

Source - https://www.sciencemag.org/news/2018/09/humans-braved-australia-s-hostile-desert-interior-thousands-years-earlier-thought

Desert 16x9 0The Little Sandy Desert region of Australia’s Western Desert - INGO OELAND/ALAMY STOCK PHOTO

Humans trekked into Australia’s vast, harsh Western Desert almost 50,000 years ago—10,000 years earlier than thought and just a few thousand years after people first arrived on the continent, a new study suggests. The research offers the earliest evidence of aboriginal occupation in the region and underscores how quickly the colonizers adapted as they spread into the continent’s arid interior.

Humans came to Australia about 65,000 years ago. Artifacts and remains of ancient campfires suggest that, after arriving on the tropical northern shore, the first Australians reached the west coast and southern Australia 49,000 to 50,000 years ago. But little was known about when they reached western Australia’s interior, a region of hot, red sand flats and dunes punctuated by a jumble of quartz and sandstone mountains.

The new study helps answer that question. A team led by archaeologists Peter Veth and Jo McDonald of The University of Western Australia in Perth investigated a site known as Karnatukul, which lies within a subregion of the Western Desert called the Little Sandy Desert. The ancient rock shelter, weathered into a sandstone cliff, has yielded thousands of objects—stone tools and other artifacts, as well as charcoal and more recent rock paintings of snakes, turtles, and human figures—that suggest the area remained a popular stop for native Australians for tens of thousands of years. 

When Veth, McDonald, and colleagues began to excavate the shelter floor, they discovered a small, crescent-shaped stone tool beneath rocks that had fallen from the roof as it weathered over time. The tool was probably used for processing wood or as part of a spear. Radiocarbon dating the sediment layers surrounding the tool revealed that it was about 43,000 years old—10,000 years older than similar tools found elsewhere on the continent. The team also found an iron scraper—likely used to clean meat off hides—dated to about 47,000 years ago.

But people could have arrived at the site even earlier, McDonald says. “Fifty thousand years is the limit for radiocarbon dating, so we really are at the edge of the barrier, and that’s why it’s possible this site is even older.”

Together, the findings indicate that people had reached this part of Australia at least 47,000 years ago, and likely before that, McDonald and colleagues report this month in PLOS ONE.

Rachel Wood, a radiocarbon dating expert at the Australian National University in Canberra who was not involved in the study, says she agrees the site is at least 45,000 years old. But she draws the line there. It’s difficult to put an exact timestamp on the artifacts based on the charcoal found in the same spot, she explains. “Because the charcoal may not have been made by people, it’s hard to say whether the charcoal and stone tools were deposited at the same time, and the tools may have moved around over time” from one sediment layer to another, she wrote in an email.

The results confirm the adaptability, innovativeness, and dynamism of early aboriginal settlers in exploring and colonizing some of the toughest to live places on Earth within a very short space of time,” wrote archaeologist Chris Clarkson of The University of Queensland in Brisbane, Australia, who was not involved in the study, in an email from the field.

The team is still analyzing bits of ancient DNA and other material found at the site, which the researchers hope will offer some insights into how people eked out a living in the arid interior.