This report book contains zircon - derived U-Pb geochronological data, which was obtained between January 2005 and April 2006, for basement rock samples taken from the Gawler Craton of South Australia. The data has been generated as part of the National Geoscience Agreement, in a collaborative research project conducted between the Office of Minerals and Energy Resources of the Department of Primary Industries and Resources, South Australia, and Geoscience Australia. The aim of the ongoing project is to provide geochronological constraints on geodynamic and tectonic models for geological provinces of South Australia, and to help meet the objective of providing an improved geological and metallogenic evolutionary framework for these provinces. This report describes the samples analysed and the analytical results obtained for the Gawler Craton in Year 1 of the research collaboration, and provides a brief discussion of their geochronological interpretation. The broader geological implications of the data will be published elsewhere. The complete data files, including data for QGNG and Temora standards, will be stored in the Geoscience Australia database, OZCHRON. A summary of the U-Pb zircon ages obtained in studies completed to date is presented at the front of the subject report book in tabular format.