Two areas that were believed to cover part of the concealed south-eastern margin of the Peake and Denison Domain of the northern Gawler Craton were taken up by the Monax-Antofagasta copper exploration consortium to explore for possible buried economic iron-oxide associated copper-gold (IOCG) mineralisation, probably of Cloncurry style. An earlier review of past exploration data had revealed a significant gravity high feature, without an associated magnetic response, at Eitzen Bore, and an isolated but coincident gravity and weak magnetic anomaly at Ruby Hill, both of which undrilled geophysical features the partners thought might be caused by basement magnetite/haematite breccia systems that had developed during emplacement of the 1530 Ma Lagoon Hill granite, which outcrops not far away to the north. During the first licence year, in May 2013, Monax Alliance acquired detailed gravity surveys on NE-SW aligned grids over both anomalies, using 250 m x 350 m/500 m/700 m station spacings, with 555 new stations read at Eitzen Bore and 527 at Ruby Hill. Modelling of the gravity data from Eitzen Bore indicated that the >3 mGal anomaly is 5 km long, with a source body depth of between 300 m and 700 m. For Ruby Hill the anomaly covering an area of 5.6 km x 2.2 km was found to have a 4 mGal amplitude, with a likely source body depth of between 300 m and 875 m. This latter dense body was considered to have IOCG potential. Following its evaluation of the results of the gravity surveys, Antofagasta made the decision to not take up its option to earn an additional 19% interest in the licences beyond its strategic 51% stake. No further work ensued on the subject licence area over the next 21 months. Having deliberated over the modelled depth of the Ruby Hill target, and the costs and risks entailed by the known difficulties of drilling through the Great Artesian Basin cover sediments, Monax Alliance decided to relinquish tenure.