Archaean, Early and Middle Proterozoic rocks of the north-western Gawler Craton have features which suggest good prospectivity for base metals, precious metals and other commodities. However, outcrop is poor and there has been relatively little exploration in the region. A report by Youles (RB 91/00105) has summarised previous exploration and highlighted prospective areas of part of the north-western Gawler Craton. In late 1991 SADME carried out an extensive regional program of reverse circulation drilling to bedrock on parts of the TARCOOLA, BARTON and TALLARINGA 1:250 000 map areas. 501 holes totalling 16,872 m (average 33.7 m) were drilled on traverses mainly along existing tracks, at intervals of between 2.0 and 0.5 km. Ground magnetic surveys were also carried out along all traverses, with coverage totalling 668.2 km in 45 traverses. Concurrent with the drilling program, LANDSAT TM imagery covering the study area was processed and briefly assessed. This work resulted in the siting of a diamond drillhole on a possible hydrothermal alteration zone. An airborne GEOSCAN multispectral scanning survey was also carried out over part of TARCOOLA, including this site. The rotary drilling program showed substantial anomalous base metal and gold values, including the following: - Gold in Archaean Mulgathing Complex rocks. Anomalous values tend to be associated with paragneisses and banded iron formation rocks, and there is a concentration of anomalous holes in the Woomera Tank to West Well area. Best assay value was 700 ppb Au over 10 m at Woomera Tank. Several other holes have values in the 50-300 ppb range. - Ni, Cr (Pt, Pd) and Cu, Zn in Mulgathing Complex mafic rocks (meta volcanics?), mafic gneisses and gneisses. - Numerous elevated Cu and Zn values (maxima 2935 ppm Cu, 1660 ppm Zn) in an Early Proterozoic (?) intermediate to basic intrusive complex (the Muckanippie anorthosite complex). Similar Cu and Zn anomalies were also obtained in granitic and pegmatitic rocks on the southern margin of the anorthosite complex. - Cu, Zn, Pb, As and Au anomalies in Mid Proterozoic Gawler Range Volcanics. Maximum values obtained were 320 ppm Cu, 785 ppm Zn, 980 ppm Pb, 630 ppm As and 57 ppb Au. Highest Pb and Zn values were on a magnetic high south-east of Birthday Quarry.