Five geophysical traverses have been made across an elongate regional gravity low centred on Durkin Outstation on the Mulgathing pastoral lease, in order to try to locate and outline the shape and depth of a previously discovered palaeochannel incised within Lower Proterozoic gneissic basement. A total of 50.4 line km of seismic refraction profiling was done along all five lines, while 250 gravity stations were read on three of the lines. The work has disclosed a channel structure at least 300 m deep that is probably filled with Recent, Tertiary and Lower Permian fluvial sediments, overlying a possible weathered basement layer developed on top of the crystalline basement rocks.