As part of a regional search for possible buried diamondiferous kimberlite within an area lying 50 km north-east of Tarcoola, 15 discrete magnetic anomalies regarded as having possible kimberlitic sources were recovered by means of ground magnetic traverses covering 16 line km. In addition, a discrete large (8000 nT) aeromagnetic anomaly, previously designated A1 by Samedan Resources, which was considered as having potential for Olympic Dam type mineralisation, was further defined by 7.35 line km of ground magnetics and 8.5 line km of detailed gravity profiling. The results were geophysically modelled by CRA to select optimum drilling locations. In the area now relinquished, 7 RC/aircore holes were drilled for an aggregate of 516.5 m. Two holes (83GRC6 and 7) were drilled over the A1 anomaly (215 m total), while the other five holes (83GRC1-5) were drilled over four selected kimberlite targets (for 301.5 m). A rotary mud/rotary percussion drillhole (RD/PD 84GD1) was also later drilled into the A1 anomaly. Loam samples were collected over seven selected kimberlite magnetic targets and were submitted for indicator mineral analysis plus, in two cases, for microdiamond analysis. All results were negative. All three CRA drillholes testing the A1 anomaly encountered acid igneous bedrock lithologies, probably belonging to the Gawler Range Volcanics suite. The last-drilled hole, RD/PD 84GD1, was able to explain the observed magnetic and gravity anomalies, which are caused by magnetite accumulations within the volcanics. Drilling of the kimberlite targets was hampered by thick Cretaceous and posible Permian cover sediment sequences. Holes 83GRC1 and 83GRC2 successfully reached basement, which consisted of non-magnetic felsic rocks, also attributed to the Gawler Range Volcanics. The remaining holes failed to pass through the cover sediments. It is concluded that the magnetic anomaly sources are either deeper than was geophysically modelled, or are present as maghemite concentrations in undetected ?Tertiary palaeochannels existing close to the ground surface.