Comprises details of the operations, field acquisition, results and interpretation of the seismic survey. Five lines totalling 20 miles of 4- and 6-fold reflection seismic were recorded. The survey aimed to investigate the NW flank of the Merrimelia High and its relationship with the Gidgealpa High. Interpretation was difficult because of diffraction and other forms of interference arising from the large fault system. However, the more modern techniques used reduced some of the problems previously encountered in this area, and provided a much improved picture of the structure and stratigraphy. A series of shallow refraction surveys (36 profiles at 28 locations) were also made to investigate the depth of weathering in the Merrimelia area. No structural closure was found on the Swan Lake nose, but the greatly increased stratigraphical detail indicates the possibility of stratigraphic/fault traps in the Tirrawarra Formation.