Changing adaptations in the Dampier Archipelago

The scarcity of datable sites means that it is difficult to develop a timeline for the occupation of the Dampier Archipelago. Because of development pressures, archaeologists have commonly focussed on the range and distribution of cultural heritage in particular areas rather than looking at change through time. Investigating questions about how long people have lived in the area and how people have interacted with changing environments through time is difficult on the Dampier Archipelago because rock shelters in which sequences of occupation layers can develop are rare and most occupation sites are simply open scatters of stone artefacts and shells.

Rock art is extremely difficult to date because it is unusual to find it in association with datable occupation deposits. Even rock art that has been covered with datable deposits can only be given a minimum age. For example, the rock art found in the Skew Valley excavation must be more than 3800 years old, but exactly how much older cannot be determined easily. Methods of dating that rely on measuring degrees of weathering or growth of micro organisms remain controversial or experimental. It is, however, possible to propose relative chronological sequences based on differential weathering, differences in style and technique, and superimposition of images. The depiction of animals that are now extinct can also offer dating clues, while many of the marine motifs most probably date to the period of the formation of the Archipelago and after. The fresh and unweathered petroglyphs are clearly very recent indeed. Some images that can be linked to the ceremonial and mythological beliefs of Pilbara people today might also provide clues to dating.

Australia was settled by about 50,000 years ago during the last Ice Age, at a time of lowered sea level. At this period the Dampier Archipelago would have been an area of rocky hills and ridges rising out of a broad plain, with the coast more than 100 km away. Climatic conditions during the last Ice Age fluctuated markedly, but were generally cooler and drier than today. Between about 50,000 and 35,000 years ago, conditions were cool but reduced evaporation rates generally meant they were also relatively wet. About 35,000 years ago, temperatures and rainfall began falling. The polar ice caps were at their greatest extent at the Last Glacial Maximum (LGM), about 20,000 years ago, and sea levels were at their lowest. The period from about 25,000 to about 13,000 years ago was particularly harsh, with very dry, cold and windy conditions. Like desert dwellers in central Australia in the recent past, the population would probably have comprised small highly mobile groups and ranged widely between reliable water sources.

There is plenty of archaeological evidence that people were living in the north-west of Western Australia by about 30,000 years ago. Habitation on what is now the Cape Range peninsula dates back more than 30,000 years, while there is evidence for occupation of what are now the Monte Bello Islands from about 27,000 years ago. Several inland Pilbara rock shelters have occupation deposits dated to more than 20,000 years ago.
The oldest dated evidence from the Dampier area is a trumpet shell from Gum Tree Valley radiocarbon dated to 18,500 years ago. However, it is reasonable to assume that the ‘Dampier Ranges’ were also visited before this date, perhaps by people who also visited the ancient coastline and inland ranges. The most ancient art probably dates to this period. The famous ‘archaic faces’, which archaeologists believe are among the oldest art in Australia, are found in the Dampier Archipelago and far inland at sites such as Cleland Hills in central Australia. These motifs may represent evidence of cultural connections over very long distances.