Regolith 2005 – Ten Years of CRC LEME 64 PEDOGENIC CARBONATES, STRONTIUM ISOTOPES AND THEIR RELATIONSHIP WITH AUSTRALIAN DUST PROCESSES

Approximately 21 % of the Australian land surface is covered by pedogenic carbonates (Figure 1) that have formed in soils, saprolite, sediments and similar regolith materials (Chen et al. 2002). These carbonates are abundant in much of the semi-arid and arid regions of Australia and are a significant continental sink for calcium (Ca). The Ca may be derived from either in situ weathering of bedrock or external atmospheric sources. Identifying the relative mixtures of these two end-member components has important implications for understanding the behaviour of Ca in the continental weathering cycle. Figure 1: Location map and interpretive distribution of regolith carbonates, adapted from Chen et al. (2002)