Exploration for possible kimberlite pipes in the Mount Arthur - Mount Toodla area, 30 km east-southeast of Oodnadatta, has included preliminary gravity and ground magnetic surveys, stream sediment sampling, and the drilling of a single diamond cored hole to 250.78 m total depth to investigate a local gravity high. The drillhole passed mostly through a section of Mesozoic sediments, including an artesian aquifer forming the section's basal 20 m interval, before encountering and coring part of a unit of sheared, highly altered gneissic/amphibolitic metamorphic basement over the last 1.5 m of the hole. When heavy mineral concentrates from 11 bulk samples of alluvium were processed in a metallurgical laboratory, scattered high nickel, cobalt and chromium values were inferred to be probably related to high iron contents within ferruginised Cretaceous limestones that were seen outcropping adjacent to the sampling sites. Three of only five hand-picked garnets from the stream sediment heavy mineral concentrates, when analysed for their MgO content, showed appreciably more of this than the 11% required for them to be classified as of pyrope rather than almandine composition, so the two source samples have been classed as containing pyrope kimberlitic indicators. However, when 105 ilmenite grains obtained from the same two samples were similarly analysed, their MgO contents were found to be much lower than the values generally attributed to kimberlitic ilmenites. Furthermore, no microdiamonds were recovered.