Ice Age cave find upends what we know about Australia’s first people

Glacier landscapes may not have been hurdles for early human migration, study suggests

Archaeologists have unearthed rare artefacts dating to the last ice age at a cave in Australia’s Blue Mountains, providing definitive proof that the rugged ranges were once occupied by the continent’s first people.

Researchers working with First Nations community members found that Dargan Shelter, a frigid site at an elevation of about 1073m (3280 ft) west of Sydney, was occupied by early humans 20,000 years ago.

The findings, published in the journal Nature Human Behaviour, provide the oldest evidence yet of occupation above 700m in Australia.

It upends previous beliefs that the Blue Mountain ranges were too difficult to occupy during the last ice age, and also hints that such icy landscapes may not have been a hurdle for early human migration.

Dargan Shelter on Dharug Country in upper Blue Mountains (Dr Amy Way)

The research also raises further questions about the ingenuity of early indigenous Australians that enabled them to adapt to these inhospitable conditions.

During the last Ice Age, frigid conditions extended to the upper reaches of the Blue Mountains above 600 metres with temperatures at least 8.2 degrees cooler than today, and vegetation much sparser than modern times.

Little firewood would have been available in this region during the ice age, and water sources would have been frozen through winter, scientists say.

“Until now, we thought the Australian high country was too difficult to occupy during the last ice age,” said archaeologist Wayne Brennan from the University of Sydney.

“Yet, despite the harsh conditions, our research demonstrates people were moving in and through this high elevation landscape, which is approximately 400m above the treeline,” Dr Brennan said.

In the latest excavations, archaeologists unearthed nearly 700 artefacts at the cave site dating to the last Ice Age, including features of a hearth.

Many of these were prehistoric tools likely used by Australia’s first people for cutting or scraping, researchers say.

“It was the excellent state of preservation that enabled us to construct such a robust chronology for Dargan Cave spanning the last 20,000 years,” said Philip Piper, another author of the study.

Most of the claystone tools unearthed were made locally, but one seems to have come from the Jenolan Caves area, which is about 50km (31 miles) away from the Dargan Shelter site, indicating ancient people were travelling from the north and south.

Dargan Shelter excavation (Meagan Warwick/Australian Museum)

While the Blue Mountains range is a UNESCO World Heritage-listed site recognised for its plant and animal diversity, there have been no safeguards to protect the cultural heritage of its indigenous people, researchers say.

“Our people have walked, lived and thrived in the Blue Mountains for thousands of years and we knew the cave was there,” said study author and Dharug woman Leanne Watson Redpath.

“It is not only a tangible connection to our ancestors who used it as a meeting place for sharing, storytelling and survival, but is a part of our cultural identity. We need to respect and protect our heritage for the benefit of all Australians,” she said.

Scientists are still unsure which early people accessed the mountains during the last Ice Age.

They suspect multiple indigenous groups may have been connected to the region.

“We hope that by combining our traditional knowledge with scientific research, we can protect these invaluable storehouses of our history for generations to come,” Dr Brennan said.