Australian rock art shows some of the oldest-known artistic images by modern humans. However, there are considerable technical difficulties and uncertainties in dating rock art which make it difficult to determine the age of Australia's earliest rock art. Australian rock art, while extensive and in places of great age, is nevertheless not the oldest in the world. Both rock art and portable palaeoart were made long before Australia was apparently first settled. The oldest currently known rock art is in India, at such sites as Auditorium Cave and Daraki-Chattan, but similar Acheulian rock art is believed to exist in the Kalahari Desert of South Africa. Arrival of humans in Australia Archaeological evidence suggests that humans first arrived in Australia between 65,000 and 60,000 years ago. Northern Australia is the most likely place for people to have travelled from south east Asia across the land bridges then sailed across the ocean gaps to northern Australia. Archaeologists have now discovered early occupation sites at the three most probable entry areas - the Kimberley, Arnhem Land and Cape York Peninsula. In northern Australia there are numerous sandstone rock-shelters. Many of these have been used for camping and their floors are layered with charcoal and ash from camp fires, the remains of food such as shells and animal bones, stone tools and, very often, pieces of ochre. Ochre comes from soft varieties of iron oxide minerals (such as haematite - a fine-grained iron oxide which produces a strong red colour with a purple tint) and from rocks containing ferric oxide.  Nauwalabila shelter in Kakadu National park, Arnhem Land
Stone tools and ochre are the toughest of this camping debris. Their appearance in the layers of material on the floor of the shelter is usually interpreted as the beginning of occupation at the shelter. Charcoal may or may not have survived in the lower layers of a site, depending on local preservation conditions, and other organic material tends to survive in only the youngest part of the deposit, spanning at the most a few thousand years. How do we estimate the age of Australian rock art? The best way to establish the age of rock art is to date the art directly (such as by dating a sample of the paint or pigment used) or indirectly (for example to obtain a minimum age for the art work by dating something that lies on top of the art - say a mud wasp's nest or a natural chemical coating - or lies in a layer of material with objects or matter that can be dated). In the case of rock painting in Australia, dates have been obtained for pigment directly on the walls and for painted fragments buried in deposits of campsite material. For an interesting discussion of issues to do with dating Arnhem Land rock art, see the article by Chippindale and Tacon. Techniques for dating have usually involved radio-carbon dating of material associated with the art, but there are also newer techniques now available including optically stimulated luminescence (OSL) and accelerator mass spectrometry (AMS). These are described in the page on Dating Rock Art by Robert Bednarik. Radiocarbon dating is limited to a maximum age of around 40 000 years, and the newer techniques are required for dating of older materials. AMS is a new radiocarbon dating method enabling the dating of much smaller samples of carbon than the traditional radiocarbon (C-14) method. What are the Earliest Dates for Australian Rock Art?Ochre is the main pigment used in rock art and is plentiful across most of Australia. Pieces of ochre, including some showing signs of wear through use, have been found in almost all of Australia's ice-age sites. Most have been radiocarbon dated and the dates range from 10 000 to 40 000 years. Does the use of ochre necessarily imply painting? As well as rock art, ochre has many other uses in modern Aboriginal ceremony, and is repeatedly found in association with burial not only in Australia but also in other parts of the world. In Arnhem Land, there is no certainty either that ochre was used for painting from the beginning; or that painting with ochre was on rock surfaces (rather than on perishable subjects); or that the first paintings on rock are amongst the ones that survive. However, the hardness of much of the ochre found in deposits strongly suggests that it was used on rock or other hard surfaces and the pattern of wear is totally consistent with use of the ochre in art. The oldest dates so far found by direct dating of art were obtained by geologist Alan Watchman for layers of pigment in two rock-shelters on Cape York in north Queensland, one of 25 000 years and one of almost 30000 years. There is, however, indirect evidence going back a lot further, leading some archaeologists to argue that the rock art galleries in northern Australia are some of the oldest in the world by modern humans. This is, of course, a contentious area, with recent claims for dates in southern France and northern Italy going back as far as 35 000 years. |