Miscellaneous publications have given geological descriptions of the area and no important new geological discoveries have been made affecting the gelogical conclusions. Tertiary sediments, which overlie the PreCambrian slates, yield only limited groundwater supplies of varying salinity. The wells in these sediments are nearly all out of use. The Pre-Cambrian slates of the Adelaide system normally contain sufficient groundwater supplies to be considered for irrigation purposes. There appears to be a relatively wide range in the amount of dissolved salts, and in the western portion groundwater is of inferior quality, compared with the groundwaters in other parts of the district.