By Jim Brace-Thompson
Exactly when humans first arrived in places like the Americas and Australia is the subject of vigorous debate. Some believe humans made their way to the isolate+d island continent of Australia as far back as 65,000 years ago, but concrete evidence confirming a date-of-arrival has been frustratingly elusive. Now one group of researchers writing in the journal Geology believes they’ve found evidence of human habitation written in stone.
Argon-Argon Dating And Oral Histories
Aboriginal peoples of Australia have an oral tradition of passing down stories across generations. These stories could be some of the oldest in the world. One such story, told by the Gunditmjara people living near the Budj Bim Volcanic Complex in the southeastern Australian state of Victoria, seems to refer to volcanic eruptions. Yet, the Budj Bim Volcanic Complex has long been dormant.
A team of researchers, including Erin Matchan (University of Melbourne), examined samples of some of the oldest volcanic rocks from Budj Bim using sophisticated argon-argon dating methods and arrived at a date of 37,000 years old. In the course of their research, her team also ran across a reference to a stone ax that had been found 76 years ago beneath a layer of volcanic ash in yet another area known as the Tower Hill Volcanic Complex. Dating volcanic rocks from that area also delivered the date of 37,000 years. Thus, with oral traditions that seem to describe erupting volcanoes and a human artifact, these scientists believe they have found concrete geochronological evidence in the rocks confirming human habitation in Australia for tens of thousands of years.
Some, however, are saying the evidence is merely “suggestive without being conclusive.” If indeed eruptions had been witnessed by ancient peoples at Budj Bim, they could have occurred much more recently.
Although the first eruptions here took place 37,000 years ago, the last eruptions before the volcanoes went dormant have date back 8,000 years. Previous estimates of the age of that stone ax at Tower Hill also put it at a much younger age of between 4,000 and 6,000 years. And so the debate continues!