Drilling of 1 rotary mud and 4 diamond holes (total 1447.2 m, including 602 m of rotary mud precollars) on the Mabel Creek gravity high, initially searching for Olympic Dam type Cu-U-Au mineralisation, found that several large coincident gravity and magnetic anomalies were due to significant deposits of folded Early Proterozoic banded iron formation (at least 140 m in true thickness), overlying an older metamorphic basement consisting of skarn-like rocks, garnetiferous granulites, felspathic gneisses, and minor amphibolite. Drilling of the inferred most prospective gravity anomaly, looking for possible polymetallic ores in a carbonate-silicate-sulphide facies BIF which had earlier been located in a basal position beneath thick oxide facies BIF, was unsuccessful, encountering only trace amounts of pyrite in this particular unit, beneath Permian and younger sedimentary cover. The oldest rocks penetrated were dated using Rb-Sr methods at between 2650-3310 Ma (samples of felspathic gneiss from DDH PB1). The BIF lithology was dominantly quartz and magnetite, with some haematite, and minor accessory anthophyllite, talc and hypersthene, plus trace pyrite and pyrrhotite. Its total iron content is of the order of 15-30%. Three selected samples of the BIF were sent to BHP's Whyalla Steel plant for beneficiation testing. All of the samples easily yielded high grade concentrates via wet magnetic separation techniques, with a high recovery of the magnetite present. However, the depth of burial of the BIF beds sampled, and their low in-situ grade relative to Middleback Range ore (>60% Fe), would seem at present to preclude their consideration as an economic source of iron ore.