Australia

In the center of Australi a is a large sedimentary basin or depression spanning 450 mi (720 km) from east to west and 160 mi (256 km) north to south at its widest point. Sedimentary rocks of all varieties can be found in the basin rocks which erosion shaped into spectacular scenery including Ayres Rock and Mt. Olga. These deposits are mostly of pre-Cambrian age (over 570 million years old), while sediment along the present-day coastline including those in the Eucla Basin off the Great Australian Bight are less than 70 million years old. North of the Eucla Basin is the Nullarbor (meaning treeless) Plain which contains many unexplored limestone caves.

Dominating interior southern Queensland is the Great Artesian Basin which features non-marine sands built up during the Jurassic period (190 million to 130 million years ago), sands which contain much of the basin's Artesian water. Thousands of holes have been bored in the Great Artesian Basin to extract the water resources underneath but the salt content of water from the basin is relatively high and the water supplies have been used for livestock only.

The Sydney basin formed over the folded rocks of the Tasman geosyncline and is also considered to be an extension of the Great Artesian Basins. Composed of sediments from the Permian and Triassic periods (290 million to 190 million years old) it extends south and eastward along the continental shelf. The sandstone cliffs around Sydney Harbor, often exploited for building stones, date from Triassic sediments.