An archeologist says tests show Aboriginal rock art in an Outback cave was made 28,000 years ago, making it the oldest in Australia and among the oldest in the world, the Associated Press reported.

The dating of one of the thousands of images in the rock shelter known as Nawarla Gabarnmang will be published in the next edition of the Journal of Archaeological Science.

University of Southern Queensland archeologist Bryce Barker said Monday, June 18 that the rock art was made with charcoal, so radiocarbon dating could be used to determine its age.

Most rock art is made with mineral paint, so its age cannot be accurately measured.

Australian National University archeologist Sally May, who is not involved with Barker's research, described his find as "incredibly significant."