Exploration of an area situated between Whyalla, Iron Knob and The Bluff overlooking Myall Creek, 20 km south-west of Port Augusta, aimed to test for Olympic Dam - type Cu-U-Au mineralisation associated with products of igneous activity located in and around the Roopena Fault system, i.e. at the Middle Proterozoic / Adelaidean boundary, this search being prompted after SADME in 1967 and then again in early 1978 dislosed Cu-bearing breccias and sediments in their Roopena DDH1 and DDH1a stratigraphic drilling. Work carried out by Samedan under EL 398 consisted of 1:40,000 scale geological mapping of target Adelaidean, Carpentarian and Early Proterozoic age stratigraphic units, plus outcrop rock chip, soil and stream sediment sampling, which yielded numerous structural, facies and geochemical anomalies worthy of further investigation. Over the period January-September 1979 Samedan's initial stratigraphic and exploratory drilling, which comprised 285 RAB holes (total 2472 m) and 6 shallow diamond core holes (total 551.1 m), confirmed the existence of stratabound Pb-Ag and Cu-Pb-Ag-Co mineralisation within the pre - Pandurra Formation volcanic - metasedimentary 'Fresh Well Formation' (at the Fresh Well prospect) and of similar style Cu-Pb-Zn mineralisation within the underlying Corunna Conglomerate equivalent 'Mount Laura Formation' (at the 1050 prospect). At Fresh Well prospect, the sulphide mineralisation occurs at shallow depth (25-70 m) and occupies up to a 45 m thick interval within flat-lying Middle Proterozoic sediments (lithic ?volcanogenic sandstone and dolomitic siltstone with barite/siderite veins) that are interbedded with vitric tuffs and amygdaloidal basalt flows. In February 1980, Esso farmed-in to earn 25% of EL 398, and tested several Roxby Downs - type gravity and magnetic anomalies for possible Olympic Dam - type mineralisation, besides helping to broaden the search around the Fresh Well and 1050 prospect grids. The new work entailed aeromagnetic interpretation and detailed grid-based gravity and ground magnetic surveys, plus a lot of drilling and petrographic and mineragraphic studies of bedrock samples to establish depositional, structural, metamorphic and diagenetic controls on mineral genesis. In all Esso completed 6 percussion drill holes, 4 diamond core holes and 554 bedrock RAB holes, respectively totalling 456 m / 576.3 m / 15,007 m, before exiting from the joint venture agreement in October 1982. Thereafter Samedan continued alone exploring within the Carpentarian fault basin sediments and mainly along a metasomatically altered breccia zone adjacent to the Angle Dam Porphyry (at the 1050 prospect and 1050 East prospect). The breccia zone contains minor Cu-Ag mineralisation in composites of altered sediments and vein components. 19 percussion, 4 diamond and 414 RAB holes were drilled, respectively totalling 2128.5 m / 450.1 m / 13,523.5 m. Some reconnaissance downhole Mise a la Masse electrical surveys and surface IP and SP traverses were run in attempts to detect buried economic concentrations of sulphides, but these methods proved largely inconclusive. Lack of encouragement from drilling and an inability to otherwise pinpoint hydrothermally - emplaced metal mineralisation saw the eventual termination of the licence after 7 years.