A circular magnetic low in the extreme north-west of SML 204, delineated by BHP aerial surveying in 1969, was investigated due to its resemblance to magnetic patterns often seen over porphyry copper deposits. The area of investigation lies at the eastern end of the Gawler Range Volcanic Complex, with the volcanics here comprising porphyritic rhyolites, tuffaceous and amygdaloidal rocks and flow-banded lavas characteristic of the lowest horizons of this complex. No evidence of mineralisation was detected during a programme of mapping and geochemical drainage sampling, nor was any further light shed on the source of the magnetic low. This anomaly could, however, reflect the presence of a late stage intrusive granite. Possible IP anomalies were recorded over outcropping volcanics one mile north of the SML 204 boundary. A recommendation to percussion drill the best of these anomalies is being considered.