AIM:To extend the regional seismic grid to areas not previously covered by the Lake Thomas, Beal Hill and Pillan Hill surveys, to find leads for subsequent seismic detailing, and to investigate the regional structural configuration to allow further assessment of the Pedirka Block's prospectivity, following the encouragement of good shows found in Poolowanna 1 drilled in 1977. Regional lines were programmed in the salt lakes area lying east and northeast of the Poolowanna structure (the Larry's Lake area), in the SE and SW corners of the block, and in the Walkandi weak lead area southwest of Poolowanna, near Pillan Hill line 76-WBG.METHODS: Survey dates: 25/5/79 - 25/11/79. Energy source: Explosives - line source (Geoflex), plus Anzomex boosters over salt lakes. CDP coverage: 1200%, and/or 600% over lines WDA-WDE during early experimentation in the Pedirka Southeast area. Recording mode: 48 channel digital - TI DFS V recorder. SP interval: 100.0, 150.0 or 200.0 metres, group interval: 100.0 or 75.0 metres.34 new lines totalling 2415 line km were acquired, including some semi-detailed work over the Walkandi weak lead. Short offset refraction shoots were used to determine the weathering profile.RESULTS:The survey located more than 20 areas of interest within the block, and enhanced the Walkandi lead for maturation as a drilling target. The Kuncherinna, Kuncherinna South, Miandana and Pedirka Southwest leads warrant immediate follow-up detail seismic work, but no immediate detailing is recommended at present for the small structures mapped in the Larry's Lake area. Similarly, seismic work on other leads found to the southwest and southeast of the Kuncherinna area should be delayed until results are available from any drilling in this part of the block.