This bulletin contains geochronological data and interpretations from the Gawler Craton of South Australia that have been completed by Mark Fanning of The Australian National University, by Geological Survey of South Australia personnel, and by industry and university collaborators. The data have been collected over the period 1992 to 2005 by performing Sensitive High-Resolution Ion Microprobe (SHRIMP) analyses of rock samples, using equipment based at the Research School of Earth Sciences, The Australian National University, as part of collaborative research programmes. The geochronology presented in this bulletin builds on the work done throughout the 1970s and early 1980s by Alan Webb and co-workers, who systematically surveyed the crystalline, and in some instances, sedimentary rocks of the Gawler Craton, and other geological provinces of South Australia, using Rb-Sr and K-Ar techniques (Steveson et al., 1971; Webb, 1978; Webb et al., 1982; Webb et al., 1986). However, the relatively low closure temperatures of the Rb-Sr and K-Ar isotopic systems and the mobility of the elements during overprinting thermal or metamorphic events resulted in many of the ages being more indicative of these later events, rather than of the age of rock formation; or else they reflected mixtures thereof. As these early studies were being completed, analysis of the U-Pb isotopic system via thermal ionisation mass spectrometry (TIMS) became routine, and was applied to zircons from the major rock units of the Gawler Craton (Cooper et al., 1985; Fanning et al., 1988). The results of Fanning et al. (1988), in particular, provided a useful platform for the numerous other geochronological studies that were undertaken across the craton throughout the late 1980s and into the 1990s. Our understanding of the crustal evolution of the Gawler Craton was further refined with the application of the high spatial resolution afforded by the SHRIMP instrumentation. The ca. 15 to 30 mm diameter spot size that characterises a SHRIMP analysis allows the study of small portions within individual zircon crystals. Because it has been found that zircon grains may record evidence of an earlier magmatic or metamorphic history within their crystal structure (e.g. Black et al., 1986), the spatial resolution of the SHRIMP tool provides a means for examining the fine-scale geochronological relationships preserved within complex zircon grains. This is extremely useful, since zircon is a common rock - forming accessory mineral that is able to survive metamorphism and melting, and thus is able to record evidence within an individual crystal of more than one magmatic or metamorphic cycle. The data reported herein have been collected over an extended period of time with the use of successively different design SHRIMP ion microprobes (types I, II and RG). Furthermore, the data were collected for a variety of purposes, ranging from reconnaissance to more detailed studies, and the mechanisms of data collection have been significantly refined as SHRIMP methods and understanding have developed over the 15-year period. Notably, when the SHRIMP program was intiated, cathodluminescence (CL) imaging of the sectioned zircon grains was not a standard part of the analytical protocol, as it did not come into use until the mid-1990s. Thus much of the SHRIMP I data from the early 1990s must be considered reconnaissance in nature, and such data is presented here in the interests of making it available on the public record, particularly as some of the ages have been presented in previous reports without a full data tabulation to support the geochronological interpretation. In all instances, however, the SHRIMP data have been reprocessed and so standardised to a common platform using SQUID software (Ludwig, 2001). Consequently, some of the ages presented here may differ slightly from those quoted in their original place of citation. Future use of the age of various units should therefore be referenced to this report. Age calculations, concordia plots and relative probability figures in this bulletin have been generated using ISOPLOT (Ludwig, 2003). The errors listed in the tables are given at the one sigma level, and the data have been plotted on concordia diagrams at this acceptance level. However, weighted mean ages and concordia intercept ages are presented as 95% confidence limits. The decay constants used are those recommended by the IUGS Subcommission on Geochronology (Steiger and Jäger, 1977). The featured samples are discussed according to geographic area of origin, within chapter sections reserved for the southern, central western and northern Gawler Craton. Two-thirds of the samples came from outcropping rocks, while the remainder were derived from drill cores.