The Skillogalee Dolomite is a 3 700 metre thick repetitive siliciclastic stromatolitic dolomite intraclastic magnesite succession deposited in rapidly fluctuating shallow marine, paralic and arid playa environments.27 samples from the Willouran Ranges from representative sedimentary environments were analysed for total organic carbon. Results for the cryptalgal dolomite and stromatolite facies (range 0.1 - 1.38% TOC) were encouraging. Analyses of 6 drill hole and 2 outcrop samples indicate post maturity with respect to hydrocarbon generation. Nevertheless, the residual organic carbon contents are sufficiently high to indicate that the algal carbonates would have been good petroleum source rocks in the past. This poor to fair residual organic richness coupled with the very great thickness of these rift related deposits implies a good overall source potential for equivalent deposits in areas that have undergone less deformation and metamorphism (e.g. eastern Officer Basin).