Australia is very interesting for its numerous natural resources. The valuable resources are mined in great scale and are one reason for the wealth of the country. Huge coal deposits are transported by train and shipped to the furnaces of Japan. Other mines produce bauxite, iron ore or uranium. The most famous minerals are the opals from the red center, mined especially at Cooper Pedy.
Mining is a major industry in Australia, and as many people live of mining, either in big mining companies or as private miners, fossicking (mineral collecting) is regulated strongly. Almost everywere a special permit is needed, in many areas it is completely forbidden. There are only a few show mines, as most of the mines are still operational. Historic mines are rare, because of the short history of this young country.
This number of different resources give a first idea about the complexity of Australias geology. Australia has rocks of all stages of Earths history. The oldest rocks are from the Precambrian era, between two and three billion years old crystalline and volcanic rocks and some sediments with the oldest remains of multicellular life on earth. They are found in the west, in the center and the north of Australia.
Most of the surface is covered by Palaeozoic and Mesozoic sediments. Most famous are the red sandstones of the so called "red center", Ayers Rock and the Olgas are outstanding examples.
Beneath the sandstone sediments there are only small patches of limestone. Most of the limestone areas were formed during the Cenozoic, which means they are rather young. The two biggest limestone areas, the Nullarbor Plains and the limestones south of Adelaide are such limestones.
The caves in Australia are often big and contain many beautiful speleothems. In the south eastern caves helictites are very common. Many caves are developed as show caves.