Up until now, normal radiocarbon dating, using accelerator mass spectrometry, has been unable to accurately date most Australian rock art. This is due to the fact that the paint used was ochre, which is an inorganic pigment and therefore does not contain any carbon.
     Now a new technique, co-produced by Dr Vladimir Levchenko, a research scientist working for ANSTO, the Australian Nuclear Science and Technology Organisation, has turned his attention to the oxalate crust which covers the rocks where the paintings occur. This crust was formed by a photosynthetic bacteria which uses carbon which it extracts from the air, ands is what is being identified and dated.
     Using this approach they have been revisiting rock art sites in Western Arnhem Land, with the full blessing of the indigenous population, tentatively dated the art to approximately 8,000 - 4,000 BCE. The one problem with this technique is that the rock art below the crust may well be a lot older than the crust itself.
     The other co-author of the paper, Ms Tristen Jones, is quoted as saying, "The results are exciting as although they generally support the chronology and assumed antiquity for the NRF (Northern Running Figures) art style, they provide minimum ages which suggest that the art style is actually a few thousand years older than what was anticipated". Dr Levchenko added that, "Indigenous Australian rock art is very interesting, it is believed to be among the most ancient in the world but it is one of the least dated!".

Edited from ANSTO (6 December 2016)