OSL dating: an essential tool for building a geoarchaeological framework - evidence from sites in Asia and Australia

Optically-stimulated luminescence (OSL) dating provides the time since sediments and their associated artefacts and fossils were last exposed to sunlight prior to deposition and is therefore an essential tool for establishing chronologies for many disciplines. Further to this, OSL dating provides the chronological link between the landscape/surface processes and human activity, which is inferred from the archaeological evidence within the sediment. No other dating technique of this age range (100 yrs-200 ka) provides this intimate connection between the sedimentary processes and the evidence for human behavior. Without this connection, robust geoarchaeological frameworks can prove difficult to construct and maintain. In this paper, we demonstrate the use of OSL dating techniques in sites across Asia and Oceania, focusing on the Tam Hang caves in northern Laos and the rock shelters of northern Kimberley, Western Australia. OSL dating has proved to be the key to understanding how the geomorphological and geological processes within the karst region of northern Laos are intimately related to human activity. Similarly, in the rock shelters of northern Kimberley OSL dating of the sand sheets within the occupation sites and mud wasp nests over the rock art is critical for developing a geoarchaeological framework for understanding the behavior of the first Australians. This framework is of particular importance as these locations may contain some of the oldest signs of modernity on the continent.