Neoproterozoic stratigraphy of the Centralian Superbasin, Australia

The basement of central Australia includes the Arunta Block and the 1200-1100 Ma Musgrave Block succeeded by 1075-1000 Ma bimodal volcanic rifts and dolerite dykes. A regional hiatus at 1000-800 Ma, interpreted as reflecting a central post-volcanic (underplated) upland, was followed at 800 Ma by a second swarm of dykes in the Musgrave Block, Gawler Craton and Stuart Shelf, associated with the crustal sagging that initiated the Centralian Superbasin. The Centralian Superbasin is defined here to encompass the Neoproterozoic fill of the Amadeus, Georgina, Ngalia, Officer and Savory Basins. The intra-cratonic superbasin was disrupted internally 540-600 Ma ago ("Petermann Ranges Orogeny") by a central uplift and associated thrusts, and by mid-Carboniferous (320 Ma) tectonism ("Alice Springs Orogeny") to form the structural basins listed above. The stratigraphy and sedimentology of the relatively well known areas can be used as a basis for predicting those of the poorly known regions. New results from acritarch biostratigraphy and isotope chemostratigraphy, in conjunction with conventional lithostratigraphy and sequence analysis, allow better stratigraphic resolution than previously possible. Field observations in the recently discovered Savory Basin in Western Australia provide a basis for correlations with the adjacent basins.