South Australian Gulf and Yorke Cenozoic Basins hydrogeological inventory

This South Australian Gulf and Yorke Cenozoic Basins dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus.

The South Australian Gulf and Yorke Cenozoic basins consist of eleven separate basins with similar sediments. These relatively small to moderate-sized basins overlies older rocks from the Permian, Cambrian, or Precambrian periods and are often bounded by north-trending faults or basement highs. The largest basins, Torrens, Pirie, and Saint Vincent, share boundaries.

The Torrens and Pirie basins are fault-bounded structural depressions linked to the Torrens Hinge Zone, while the Saint Vincent basin is a fault-bounded intra-cratonic graben. Smaller isolated basins include Carribie and Para Wurlie near the Yorke Peninsula, and Willochra and Walloway in the southern Flinders Ranges. The Barossa Basin, Hindmarsh Tiers, Myponga, and Meadows basins are in the Adelaide region. These basins resulted from tectonic movements during the Eocene Australian-Antarctic separation, with many forming in the late Oligocene. Sediment deposition occurred during the Oligocene to Holocene, with various environments influenced by marine transgressions and regressions.

The well-studied Saint Vincent Basin contains diverse sediments deposited in fluvial, alluvial, deltaic, swamp, marine, littoral, beach, and colluvial settings, with over 30 major shoreline migrations. Eocene deposition formed fluvio-deltaic lignite and sand deposits, before transitioning to deeper marine settings. The Oligocene and Miocene saw limestone, calcarenite, and clay deposition, overlain by Pliocene marine sands and limestones. The uppermost sequences include interbedded Pliocene to Pleistocene limestone, sand, gravel, and clay, as well as Pleistocene clay with minor sand lenses, and Holocene to modern coastal deposits. The sediment thickness varies from less than 50 m to approximately 600 m, with the Saint Vincent Basin having the most substantial infill. Some basins were previously connected to the Saint Vincent Basin's marine depositional systems but later separated due to tectonic movements.