Result of 2 months field work (2 men, 1 vehicle). Recommends two vehicles (one supply truck) in future. Reviews evidence for existence of Officer Basin and probable limit (See Env 0057). GEOLOGY: Superficial material (kunkar, laterite, duricrust or desert sandstone kopi). Emu Sandstone: fine to medium grained, micaceous (up to 10%) quartz sandstone. Up to 60 thick at Emu. Maximum dip 7 degrees (??Permian). Shale (eg. 29 12 S, 131 37 E), highly weathered, may be associated with Emu Sandstone Stonehenge beds (29 06 S, 131 55 E), thinly bedded siltstones and shales with calcareous and one sandstone bed, 70 thick (age unknown). Mount Johns Sandstone: Quartzose, medium to fine grained, well sorted and rounded, arkosic where in contact with gneiss. Sprigg reports 2 thin limestone beds (GSA5-2) within a 500 feet thick sequence near Chambers Bluff. Becomes thinner to west. A few worm burrows (?0rdovician cf. NT). Proterozoic: Indulkana Range Sturtion (c.f. Peake and Dennison Ranges); Maralinga bores (?Marinoan). Brief summary of Lake Phillipson sequence and its possible significance. Recommends geophysical work with full review at end of each stage.