Abstract
The small Collie Basin in southwestern Australia contains 1500 m of Lower Permian tillite and Lower to Upper Permian continental coal measures. Lower Permian sediments were probably widespread, but subsequent Permian sedimentation was restricted to a graben by contemporaneous faulting. An earlier interpretation that the basin is an erosional feature is rejected because the sediments are basically fluvial —not lacustrine. Later (?Neocomian) faulting tilted the beds and raised a mid‐basin ridge. Low reflectance of vitrinite and high moisture content show that the coals are low rank and it is tentatively estimated that about 300 m have been stripped from the least eroded parts of the basin since the Permian.