Salt Lakes and Aboriginal Settlement: A case study at Lake Carey, southeast Western Australia

Abstract

This thesis documented and attempted to explain and predict the distribution of Aboriginal archaeological sites at Lake Carey, an intermittent salt lake (or saline playa) south of Laverton in southeast Western Australia. Although situated in the arid zone and usually dry, torrential rain in the region causes floods that fill Lake Carey at least once a decade, and probably has done so for all of the Holocene. Five study areas containing 230 artefact scatters and 18 quarries were selected to sample the pronounced geomorphological and environmental differences between the western shore, the eastern shore and the islands on the lake. The distinctive landforms and their associated vegetation communities were classified into seven landscape units and then the distribution of sites and artefacts was analysed in terms of these. An association index statistic was used to measure the propensity for sites to occur within landscape units and identify uncommon sites. Analysis of artefact lithologies indicated that the lake was a barrier to movement and the islands did not serve as stepping stones for people crossing the lake. But the claypans on the lake margin probably served as a corridor for travel around the lake following rains. Few clear associations could be demonstrated between archaeological material and the distribution of drinking water, foods, medicinal plants or stone for tools. Exploitation of waterbirds and their breeding colonies was the most likely resource attracting Aboriginal occupation. The archaeological evidence argued against large aggregations of people to harvest this resource, instead suggesting visits by small transient groups which moved clockwise around the lake. Models of Aboriginal settlement and subsistence were developed as working hypotheses to be tested by future research. The models are based on the distribution and availability of resources, principally potable water and waterbirds, and envisage that the lake and the islands were visited frequently in the months after floods. A predictive model for site occurrence was developed and a framework for assessing site significance, which will be important tools for heritage management at Lake Carey.