The Delamerian Orogeny continued in the southeast of the craton where there were extensive highlands, but marine conditions returned to central Australia as a result of a eustatic sea-level rise. The sea persisted in the Bonaparte Gulf area, with deposition of sands, and similar marine sediments, carbonates, and minor evaporites accumulated in parts of the Ngalia and Georgina Basins.

In central Australia quartz sand was deposited as intertidal and subtidal sandsheets and offshore bars on a shallow shelf. Trace fossils are abundant in these sandstones, an example being the worm tubes forming 'pipe rock' in the Pacoota Sandstone, the most important petroleum reservoir in the Amadeus Basin.

The marine shelf may, for the first time, have extended into the Canning Basin where limestone was deposited locally. On the eastern side of the craton, there was probably a connection between the Amadeus Basin and the more open shelf conditions of the Warburton Basin, and from there east into the deeper water.

Volcanism was widespread at this time along an island arc in central New South Wales, and in north Queensland. Shallow-marine sediments were deposited on the flanks of some volcanoes. Some exotic terranes (eg the Tamworth Terrane) may have 'docked' just off the Australian craton at this time.