Orientation geochemical sampling, and 1:25,000 scale geological mapping that included long sectional mapping of four railway cutting bedrock exposures in the Eudunda area, revealed pervasive low grade stratiform copper mineralisation in Sturtian interglacial sedimentary rocks, but gave no encouragement for doing more detailed investigations. 39 rock thin sections prepared from the Eudunda Arkose Member of the Tapley Hill Formation that was channel sampled in road and railway cuttings were examined to determine the unit's composition and look for lateral facies variations.