Low-level mercury anomalism, possibly originating from blind base metal sulphide orebodies lying within the Cambrian basement concealed under ~ 300 m thickness ofextensive porous sediment cover in an area on the south-western fringe of the Murray Basin, was followed up by repeat sampling of residual soil horizons at reduced, 0.1 or 0.2 mile spacings, and by extending the coverage from roadsides into the adjoining farm paddocks. Numerous problems with achieving constancy of the mercury content sampling methodology, with availability and reliability of the laboratory-based analytical instruments, and with determining presently still unknown natural factors which may affect the distribution and retention of mercury in surficial sediments, led to a decision to abandon further usage of this exploration technique, particularly as no large surface anomalies (> 500 ppb Hg) have been detected. Geochemical data is presented for the sampling which was carried out for one year from certain fixed sites at regular fortnightly intervals, to try to assess the temporal flux of mercury vapour and the effects of weather upon it.