The early Cretaceous Coorikiana Sandstone has been proven to be a bona fide exploration, appraisal and development target in the South Australian sector of the Cooper/Eromanga basin. The stratigraphically shallower, early Cretaceous Mackunda Formation has the potential to replicate the success of the Coorikiana Sandstone. This report is a comprehensive documentation of the Mackunda Formation play and is aimed at providing explorers with a better understanding of the geology and potential importance of these marginal marine to paralic sandstone reservoirs. Recent activity in the South Australian portion of the Cooper/Eromanga basin has proven successful via low-cost shallow drilling campaigns, focussing on delivering additional production rate and reserves for both oil and gas. These positive results in the Coorikiana Sandstone have not only placed the spotlight on this formation as a legitimate hydrocarbon target but it has also increased our knowledge on the importance of understanding the value of shallow hydrocarbon plays in the Eromanga Basin, like the Mackunda Formation.