Continuing exploration for sedimentary uranium occurrences in the buried Tertiary Yarramba Palaeochannel, undertaken between 1978 and 1982 by a Mines Administration (Minad) - led consortium, comprised reconnaissance and infill traverse- based open hole rotary mud drilling and downhole geophysical logging (in 142 holes, total penetration 20,503.8 m) to test palaeochannel sections interpreted from surface resistivity survey data that had earlier been acquired by Murdoch Geophysics. The previously discovered East Kalkaroo uranium deposit, located about 50 km north-west of Cockburn and 4 km north-northeast of the Honeymoon deposit, which had been assessed during 1976 to contain an indicated 1150 tonnes of grade 0.15% U308, was appraised for its feasibility to undergo in situ leach (ISL) mining. Selected coring was performed across the mineralised zones (in 9 holes, EK 1 & 2, and MTC 266 - MTC 272, for a total of 139.33 m cored) to obtain sediment samples for geochemical, radiometric and petrophysical testing. As observed in other places along a 25 km stretch of the Yarramba Palaeochannel, the uranium mineral precipitation seems to be controlled jointly by the channel fill stratification and the loci of multiple redox interfaces. At East Kalkaroo the highest grade intercepts occur in much finer sands than at Honeymoon, but these sands are still permeable enough (> 700 mD) to suggest that they can be leached successfully using conventional ISL technology. In a drilling campaign carried out during July-December 1980, 34 of 40 reconnaissance drillholes encountered significant new uranium mineralisation dispersed within a 1.4 km long and 200 m wide section of the southern bank of the main Yarramba Palaeochannel, immediately west of the East Kalkaroo deposit. Following further close-spaced drilling of this occurrence, variously called either West Kalkaroo or Honeymoon Extension, during late 1981, Minad compiled a revised resource assessment of the combined East Kalkaroo and "Honeymoon Extension" mineralisation in mid-1982. The company made only a very slight improvement to the 1976 reserve figure by deciding to exclude uranium known to be present in clay horizons and in the upper sand unit of the palaeochannel, since it was thought that this uranium was unlikely to be recovered by ISL for reasons of formation permeability, and hydrological environmental constraints, respectively. The new estimate of potentially recoverable, possible and probable combined reserves became 1100 tonnes of grade 0.16% eU3O8. Reconnaissance drilling undertaken near Wallace Bore in the north-east of the tenement area encountered reduced Eyre Formation blanket sands showing no significant uranium content, but groundwater sampling returned anomalous radon values warranting follow-up. A dispute about the partners' equity in the Yarramba Joint Venture Project arose in early 1983, which precluded further uranium exploration from taking place during the next 3 years. When SA Supreme Court arbitration of this protracted dispute was finally about to occur in August 1985, the parties managed to resolve the matter at last by agreeing to negotiate a new joint venture agreement, whereby Teton and Minad withdrew from the consortium and CSR assumed by transfer both of their existing interests. This step was taken at CSR's behest to allow exploration of the Project acreage for commodities other than "Tertiary uranium", without affecting the equity levels which the former joint venture partners hold in the three currently defined Tertiary uranium deposits on that ground. Planned first stage development of the Honeymoon uranium resource (which extends partly onto EL 1060) subsequently was deferred indefinitely because of the uranium policy of the incumbent state government, and divestment opportunities for the three Project uranium resources began to be investigated. Therefore no further uranium exploration took place on the tenement after the change of Project participants and operator.