The Ouldburra Formation is the lower of 2 major carbonate units in the NE Officer Basin. It is essentially an Early Cambrian shallow marine / epeiric sea sequence, underlain by the Murnaroo Formation and overlain by the Observatory Hill Formation. Using lithologies, textures and associated sedimentary structures, 12 major diagnostic lithofacies are defined and an environment of deposition is postulated where possible. These can be used to standardise the description of Ouldburra Formation sediments. Those lithofacies which retain a primary texture provide useful environmental indicators to interpret the cyclicity of sedimentation, which in turn will enable broad correlations between drillholes and assist in the prediction of likely facies packages to be intersected in future drillholes.