In a continuation of geochemical exploration for possible large blind base metal sulphide orebodies which may have formed within the concealed Cambrian basement, North Broken Hill carried out infill sampling of significant mercury soil anomalies (> 150 ppm Hg) at 0.1 mile intervals, and also performed fortnightly re-sampling of certain sites over a whole year to check for possible temporal variations in mercury vapour flux that could be due to the changing weather. The detailed sampling could not replicate the tenor of the mercury anomalies formerly detected in regional soil sampling on SML 198 at 0.5 mile intervals, and the strange variability of assay results was frustrating and inconclusive. The licensee commissioned Amdel to conduct applied research into the mercury halo exploration method, and a report was written. Six reconnaissance traverses laid out across the two apparently most mercury-anomalous zones situated near Mount Boothby were closely soil sampled and had ground magnetometer readings taken along them. The latter survey revealed several small magnetic anomalies, one of which lay over an exposure of adamellite that contains minor magnetite. Examinations of all of the few outcrops of granitic rock present in the licence area showed that the vein of molybdenite found previously is probably an isolated occurrence. It was concluded that the Colebatch area is not suitable for utilising the mercury halo method of surface geochemical prospecting for buried sulphide mineralisation, since the local soil types are mainly calcrete and sand, both of which are porous and transmit mercury vapour rather than absorbing it.