Upper Devonian to lower Carboniferous stratigraphy of the Pertnjara Group, Amadeus Basin, central Australia

The Parke Siltstone, Hermannsburg Sandstone and Brewer Conglomerate of the Late Devonian to Early Carboniferous Pertnjara Group in the Amadeus Basin, central Australia, have been subdivided into eight new members. The Parke Siltstone at the base is an alternating sequence of siltstone and sandstone occurring in the central part of the basin. It has been subdivided into the following members in ascending stratigraphic order—Deering Siltstone Member, Harajica Sandstone Member, Dare Siltstone Member, and Amulda Member. The overlying Hermannsburg Sandstone is the most extensive formation of the Pertnjara Group and the following members have been recognised—the quartz-rich Ooraminna Sandstone and Owen Springs Sandstone Members, both of localised extent, and the Ljiltera Member which is more widespread and forms the upper pebbly part of the formation. The Undandita Member has been erected to distinguish the interbedded sandstone and conglomerate in the upper part of the Brewer Conglomerate from the massive conglomerate underlying it. The relationship between the three formations is conformable and transitional over most of the basin except around local structures mainly on the northern margin of the basin. The lateral relationship between the Pertnjara and Finke Groups is discussed in terms of interdigitating facies. A brief summary of the structural features of the Amadeus Basin is given and the effects of the Rodingan, Pertnjara, and Henbury Movements and the Alice Springs Orogeny on sedimentation of the Pertnjara Group are discussed in terms of syntectonic deposition.