The search for underground water and mineral wealth was the principal stimulus to the growth of geology of South Australia. The state's central position within the Australian continent gives the state the advantage of hosting rocks with a wide range of ages and lithologies which are all potential (and proven) targets for mineral exploration. South Australia featured some of Australia's most recent volcanic activity and is the location of dormant volcanoes, notably Mount Gambier, which last erupted approximately 6,000 years ago.