To promote renewed regional exploration of the northern Yorke Peninsula using modern techniques and concepts, MESA as part of the SAEI programme has prepared a GIS-based data package, which incorporates a study of all available drillcore and a geological and aeromagnetic interpretation for the Maitland and Wallaroo 1:100 000 sheet areas, the site of the famous Moonta and Wallaroo copper-gold mining districts. The data package includes: - Summary logs of over 370 drill cores, highlighting lithology, alteration and mineralisation. - Geophysical images: aeromagnetics and gravity (colour and greyscale). - Geological map coverages: surface geology, interpreted basement geology, mining district geology with lodes and mines, magnetic domain and linear trend interpretation. - Drillhole locations and summary lithology for over 2100 exploration drillholes, 1140 of which penetrated more than 5 m of basement. A separate coverage gives details of nearly 6500 auger drillholes. - Over 3550 geochemical analyses of drill samples, downloaded from the MESA database. - A current Exploration Licence and Exploration Licence Applications map. - An interpretative report by consultant Colin Connor, giving a coherent, modern geological synthesis, suggested exploration models (e.g. volcanogenic massive sulphides, sedimentary exhalative base metals, skarn - type metasomatic ore deposition) and an extensive bibliography. Note: available as a digital version in ArcView or MapInfo format on CD-ROM, or as hard copy (report plus maps).