Bounded to N by Precambrian complex; to S by northern limits of Eucla Basin; to W by Precambrian shield; E boundary uncertain; to SE by Precambrian complex. Reviews topography, vegetation, climate, access. GEOLOGY: - Reviews Archaean, Proterozoic and ?Ordovician (as in Geology of South Australia). Ordovician may underlie basin sediments, as a deeper water facies. Permian. Access to Lake Phillipson is at least as possible through Officer Basin as any other route. Offers possibility of thick marine section. Cretaceous and Tertiary both possible, but no great supporting evidence. Pleistocene to Recent superficial deposits. GEOPHYSICS: - BMR aeromagnetic traverses suggest up to 10,000 feet of sediments. Gravity and ground magnetics indicate gentle, (dipping N) south shelf and much steeper, (dipping S) north shelf. STRUCTURE: - Probably flat dipping, but folded Ordovician to N (Amadeus Basin) may continue S to give structures. Petroleum prospects interesting. Definitely worth additional work.