This Eucla Basin 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 Eucla Basin, located along Australia's southern margin, covers an extensive area of approximately 1,150,000 square kilometres, housing the world's largest grouping of onshore Cenozoic marine sediments. It stretches over 2000 km from east to west and has four main subdivisions: Scaddan Embayment, Esperance Shelf, Nullarbor Shelf, and Yalata Sub-basin offshore. The basin extends about 350 km inland from the modern southern Australian coastline and terminates around 200 km offshore where it meets sediments of the Australian-Antarctic Basin.
The sedimentary succession is largely consistent throughout the entire basin. In the west, it overlaps with the Yilgarn Craton and Albany-Fraser Orogen, while in the east, the Gawler Craton and Officer Basin separate it from the Musgrave Province. The basin contains mainly Cenozoic sediments, with thicker sequences in the east due to sediment movement and regional elevation differences. The onshore Eucla Basin hosts an unfaulted sheet of sediment deposited over a south-sloping shelf during several marine transgressions. The basal units rest on a prominent unconformity above the Bight Basin, indicating a break in deposition during the separation of Australia and Antarctica. The sedimentary sequence comprises various units such as the Hampton Sandstone, Pidinga Formation, and Werillup Formation, followed by the Wilson Bluff Limestone, Abrakurrie Limestone, Nullarbor Limestone, and Roe Calcarenite.
The basin's geological history is marked by significant events such as marine transgressions during the Eocene, leading to the deposition of extensive limestone formations. The Miocene saw slight tilting of the basin, exposing the Nullarbor Plain to the atmosphere and limiting further sediment deposition. During the late Miocene to Pliocene, barrier and lagoonal transgressions contributed to the formation of the Roe Calcarenite. The Pliocene period witnessed intense karstification and the development of ferricrete and silcrete, resulting in the unique modern-day topography of the region.
