It is sometimes said that Australia is the oldest continent. It is just as often countered that this is impossible, as all the continents must be the same age. In a way, both of these statements are true. Sure, all the continents—or rather all that became the continents, either by breaking apart and drifting or running into other broken bits—appeared at the same time. However, all the other continents besides Australia are currently, or at least recently, undergoing some sort of dynamic change that makes them younger, whether we’re speaking of volcanic activity adding actual land or tectonic plate movements pushing land up (the Himalayas are still growing) or down (subduction zones where earthquakes are common). A lot of what you’re looking at on these younger continents is recently added.
In Australia, none of that stuff has happened for millions of years. The landscape is not created by volcanoes or uplift zones, but rather by erosion. The Great Dividing Range, for example, is not actually a mountain range, but rather all that is left of a huge plateau that has slowly been eaten away until all that is left is a long strip that runs like a spine up the eastern side of Australia. That’s why it was so hard for the first explorers to cross the Great Dividing Range: there were no passes. It was only finally crossed when explorers figured out you had to get on top of it, and then walk along the flat top to the other side.
Australia does have real mountains—lots of them—but most of them are fairly worn down. Australia’s highest peak is Mount Kosciuszko, which stands 7,310 feet high. Like all the rest of Australia’s real mountains, it started out much taller.
All over Australia, there are remarkable formations created by this history of erosion. Often, hard minerals that would be veins in mountains in other places stand alone because the mountains have washed away, as is the case with both Broken Hill and the long ridge of quartz known as the Great China Wall.
Other places, it is the veins which were softer, and while the surrounding rock remains, the veins are gone. This is the case with Standley Chasm, one of the wonderful formations worn into the red rock of the MacDonnell Ranges. Here, the softer rock has been eroded away, leaving a 15-foot-wide channel through the wall of rock.
Everywhere one goes in Australia, there are wonderfully wind- and water-sculpted rocks, from the “beehives” of the Bungle Bungles in the north corner of Western Australia to the Remarkable Rocks on Kangaroo Island to the fabulous caves in Tasmania.
The photo below is of Standley Chasm, which we saw on the same day we visited Ormiston Gorge. The walls close in as you get farther into the chasm, until the sky is just a strip of light far overhead.