Seven days refraction seismic work. Results from three different locations indicate that the eastern and western margins of the basin may be faulted. Displacements of the Adelaidean sediments are 50 metres on the eastern margin and 120 metres and 130 metres at two different locations on the western margin. The results suggest that at least the central portion of the Willochra Basin is a graben structure with sedimentation controlled by faulting at the margins. In the central Willochra Basin thickness of sediments increase from 130 metres at the most northerly traverse to 30 metres at the most southerly. Refraction methods can be used at reasonable cost to map the floor of the basin and outline some of the features within it.