One of the first projects undertaken by the Petroleum Exploration Section was the production of a structural contour map of the South Australian portion of the Great Artesian Basin and areas' immediately adjacent .in neighbouring states. Compilations by the. writer continued intermittently throughout 1962. Subsequently With the assistance of Michael Brownhill, student geologist, the map accompanying this report was finalized in February, 1963. New data will continue to become available regularly. Seismic prospecting and drilling in connection with oil exploration, surface geological mapping, and occasional boring for water will-all provide information which will necessitate modification of the existing map and develop a truer and more detailed structural picture. It is hoped to extend the map coverage westwards and northwards when more information, particularly hydrological, becomes available and when further mapping leads to a better understanding of the stratigraphy of the marginal zones of the Basin.