In a search for possible economic Permian coal seams buried at the southern end of the Boorthanna Trough of the Arckaringa Basin, the Petromin joint venture consortium selected an area to drill where it was inferred that such coal might lie within 300 feet of the surface, based on evidence gained from regional geophysics and past stratigraphic drillholes and water bores. An initial drill traverse was laid out in the north of EL 15 near the Stuart Highway, approximately 50 miles north of Coober Pedy, and three open rotary holes totalling 1315 feet were put down, which did not encounter coal in the target Lower Permian Mount Toondina Formation, although some carbonaceous shale is present. Hand-held scintillometer scans made over the drill cuttings did not produce any radioactivity readings above background. When unseasonal wet weather conditions had abated to allow access for heavy drilling equipment onto the remoter, more southerly parts of EL 15 and the adjoining EL 39, the licensees carried out further open hole rotary drilling along three east-west traverses spaced about 5 miles apart, completing ten holes, all to total depths of 400 feet. Most of these drillholes intersected thin uneconomic coal, as individual seams less than 1 foot thick, which all lie at depths greater than 250 feet. A minor increase in the overall Mount Toondina Formation interval sediment thickness in the vicinity of drillhole ED9 may denote some syn-depositional structural downwarping. It appears that these seams may correlate with those which were previously encountered in SADM Mount Furner 1 located some distance to the north, but here they are mostly stratigraphically thinned almost to pinchout.