The Warburton Basin consists probably of Cambrian to Ordovician deposits. This study collected 89 samples from 21 wells and introduces three acritarch assemblages of Middle Cambrian to Early Ordovician age. The acritarch assemblage from the Middle Cambrian is dominated by micrhystrids and leiosphaerids and also contains many distinct Middle Cambrian species described from Britain and Eastern Europe. The Late Cambrian assemblage from Coongie 1 contains very abundant specimens of Leiofusa cf. L. squama and Leiofusa stoumonense; nearly thirty species have been identified in this preliminary study. The third assemblage from Packsaddle 1 consists of many typical Early Ordovician acritarch elements such as Acanthodiacrodium sp., Aryballomorpha cf. A. grootaertii, Athabascaella penika, Athabascaella cf. A. playfordii and other forms, which can be used for intercontinental correlation. Three assemblages provide a standard for stratigraphic correlation among those wells lacking macrofossil evidence. The study of acritarchs from Innamincka 1 and comparison with above mentioned three assemblages indicates that the age of the Innamincka Red Beds probably ranges from the latest Cambrian to Early Ordovician. Sedimentary evidence suggests that the sequence might have been deposited in a marine delta or submarine channel and fan environment. The occurrence of kaolinite in the uppermost unit suggests a long period of erosion or leaching before deposition of the Permian rocks. The investigation of the acritarchs from Mudrangie 1 indicates that the pre-Permian rocks (Dullingari Group?) from the well are of Early Ordovician age and from Wantana 1 of Late Cambrian age. The organic matter maturity and abundance in the basin suggests that no significant source rocks were analysed, but in the Gidgealpa area there may be some source rock potential. Thermal alteration index on organic matter varies from 2 to 5; generally speaking, organic matter extracted from the wells in the southeastern part (such as the Gidgealpa region) is much more mature than those in the northwestern part (such as the Coongie - Innamincka region).