This study covers a southern lobe of the Eromanga Basin known as the Frome Embayment, which extends W-E from the Flinders Ranges to the Barrier Ranges, and southwards from the vicinity of Moolowatana Station to the Scott Hill-Mundaerno Hill region. Within the embayment the basal Algebuckina Sandstone (Jurassic) of fluviatile to lacustrine origin is overlain by transgressive Cretaceous, marginal marine Cadna-owie Formation, which grades upwards into marine Bulldog Shale. To the north, in areas overlying the southwestern Cooper Basin region, a different nomenclature is applied to the Mesozoic sequence, which here is considerably thicker than in the Frome Embayment. Lower Jurassic Hutton Sandstone and Birkhead Formation are present below the Algebuckina Sandstone equivalent, the Mooga Formation, which is further subdivided into the predominantly sandstone Namur Sandstone Member and the siltstones and shales of the Murta Member. The overlying Transition Beds, equivalent to the Cadna-owie Formation, are overlain by marine shales of the Tambo and Roma Formations. To the east, in Fortville 3, the Mesozoic section is reduced: the Murta Member is absent and the Mooga Formation is composed entirely of sandstone.