The Japan Times, June 1, 1998

Old dates questioned on Aborigine arrival

SYDNEY (AP) New research indicates that a group of Australian scientists apparently were mistaken when they announced they found tools and rock art that showed Aborigines arrived in Australia tens of thousands of years before it was previously believed.
Two years ago, the group had claimed to find Aboriginal tools in layers of sand at least 116,000 years old, and rock art that was up to 75,000 years old.
The announcement caused a worldwide sensation because it appeared to rebuff the long-accepted belief that Aborigines came to Australia from Asia just 60,000 years ago. The announcement also went against current theories about how humans evolved and migrated across the continents.
Many scientists believe Homo sapiens did not emerge from Africa until about 100,000 years ago; and the oldest reliably dated rock art had been 32,000-year-old cave paintings at Chauvet in France.
New research published in the science journal Nature suggests the original dating methods were contaminated and the Aboriginal tools and nearby Jinmium rock carvings in the Northern Territory are very recent.
"It's definitely not a very ancient occupation site. It's no more than 10,000 years old. Probably human occupation at that site started 6,000 or 7,000 years ago," Richard Roberts of La Trobe University in Melbourne said.
The art at the Jinmium site consists of thousands of dot-like indentations engraved on a group of rock monoliths in the Kimberley region, 450 km southwest of Darwin.
The Aboriginal tools were found in quartz sand originally dated two years ago by scientists at the Australian Museum and University of Wollongong.
David Price of Wollongong University heated groups of quartz crystals in a process called thermoluminescence, indicating an age of 116,000 to 176,000 years.
Chips and crystals off the nearby Aboriginal rock carvings dated the same way appeared to be 50,000 to 75,000 years old, Price found.
The findings were published in 1996 in the archaeological journal Antiquity, but were released to the mainstream press first, making a huge splash in newspapers worldwide.
Roberts and his colleagues, however, using another dating method, have found that the Jinmium sediments range in age from 4,000 to 10,000 years old. The base of the Jinmium deposit is no more than 22,000 years old, he found.
In an interview with the Associated Press, Roberts suggested that the Australian Museum and University of Wollongong research was contaminated with weathered quartz crystals that had been buried since the formation of the rock, and therefore appeared far more ancient.
Roberts and his colleagues also used radiocarbon dating on charcoal samples found in the upper two-thirds of the excavation to check his dating.
The radiocarbon dating matched his findings, but not the original researchers' date estimates, he said.
Price declined to comment on Roberts' research until after the Nature publication, but said there was no reason yet to believe his findings are not valid.
Australian Museum archaeologist Richard Fullagar, who led the Jinmium dig, was one of the authors of the original study and also a co-author of the new paper with Roberts. He said Roberts' dates "do provide some agreement with some of the carbon dating that we think is more accurate."