Wood charcoal analysis at Riwi cave, Gooniyandi country, Western Australia

Abstract

Wood charcoals excavated from archaeological sites provide a useful tool for palaeoenvironmental reconstruction, particularly in arid and semi-arid zones, where suitable catchments for palynological archives are often limited. Preservation of organic material in northern Australia is characteristically poor, and wood charcoal analysis provides a viable alternative to understand shifts in woody vegetation in the past. The analysis of charcoal from matrix contexts at Riwi cave, located in the southern Kimberley region of northern Western Australia, has allowed a reconstruction of the local woody vegetation during occupation over the last 45,000 years. The wood charcoal assemblage from the Holocene stratigraphic units reflects the composition of the modern vegetation, and illustrates that people were occupying the site during periods of relative humidity. The Pleistocene stratigraphic units show a shift in vegetation composition from Eucalyptus spp. to Corymbia sp. dominated savanna, with an understory of secondary shrub, associated with a Late MIS 3 arid event observed in both terrestrial and marine archives, suggesting that activities continued at Riwi during this arid event. Further anthracological analysis of other sites in the Kimberley will help to build a regional picture of woody vegetation change, and will further disentangle local and regional climatic signals, particularly in relation to phases of occupation.