Australia

Australia has been less affected by seismic and orogenic (mountain building) forces than other continents during the past 400 million years. Although seismic (earthquake) activity persists in the eastern and western highlands, Australia is the most stable of all continents. In the recent geological past, it has experienced none of the massive upheavals responsible for uplifting the Andes in South America, the Himalayas in south Asia or the European Alps. Instead Australia's topography is the end result of gradual changes over millions of years.

Australia. Illustration by Hans & Cassidy. Courtesy of Gale Group.

Australia is not the oldest continent, a common misconception arising from the continent's flat, seemingly unchanged expanse. Geologically it is the same age as the Americas, Asia, Africa, Europe, and Antarctica. But Australia's crust has escaped strong earth forces in recent geological history, accounting for its relatively uniform appearance. As a result, the continent serves as a window to early geological ages.