Less than two years ago, scientists at the Australian Museum (Sydney, NSW) and the University of Wollongong (NSW) announced that they had evidence that Aborigines had settled Australia a lot earlier than previously thought. In fact, they pushed the date back from 40 000 years ago to between 120 000 and 176 000 years ago.

However, this theory has now been laid to rest with new findings published in Nature ( 28 May 1998) by a team from La Trobe University (Melbourne, Victoria), CSIRO, the Australian Museum, the Australia Nuclear Science and Technology Organisation, the Australian National University, and University College, London. They place the artefacts at a mere 10 000 years ago.

Jinmium, in the Northern Territory, is home to the famous Aboriginal shelter (which is just a large block of sandstone on a tilt) where the controversy began. Dr. Richard Fullager and Dr. Paul Tacon (Australian Museum) used a heat-dating method known as thermoluminescence, but failed to wait for other dating techniques to back up their studies before publishing their findings. Now, a new technique (developed in Melbourne) called OSL, which accurately dates the time of burial of individual grains of sand, has disputed their claims. Furthermore, even good old carbon-14 dating says only 10 000 years.

Dr. Richard Roberts, a geomorphologist at La Trobe Uni and world expert in dating rocks, said that the original samples were probably tainted with sedimentary deposits. As for criticisms that the pair did not approach him before publication, Roberts states that Fullager did indeed do so, but did not want to hold off on the publication of his finds. Dr. Roberts feels this big mistake could have been avoided by checking their finds against other methods.

Dr. Tacon defended the premature publication by saying it was mainly to encourage debate, as there have long been many who feel 40 000 years is too conservative a figure for the settlement of Australia. He also argued that they stated outright that further research and dating with other methods had to be carried out. In defence of Fullager, Tacon added that his colleague had been willing to wait for other dating material, but had been uncertain how long he would have to wait, so decided to publish their findings.

The debate over the Jinmium artefacts may now be over, but the date when man first entered Australia is another matter. Many feel there is enough evidence to point to 100 000 years or more of inhabitation, while others feel 40 000 years to be too liberal an estimate. The debate continues......