285 x 210 mm, 168 pages, 120 colour plates, 100 b&w illustrations
ISBN 9781877058448, $39.95, Paperback
Some parts of the Australian landscape are more than 100 million years old. The dinosaurs roamed a land in which Kakadu, the Macdonnell and Flinders ranges, the Arcoona Plateau and the Mt Lofty Ranges, and many parts of the Yilgarn Craton of Western Australia and the Eastern Uplands were recognisably present.
Landscape remnants of equal age are probably preserved in other continents, in parts of southern Africa and South America, for instance, but a combination of circumstances has permitted many of the very old Australian surfaces to be dated with reasonable confidence. They are incompatible with the received geomorphological wisdom which, plausibly, is that as the Earth’s surface has been exposed to the elements it has suffered attack by water and rivers, wind and waves. In terms of geological time, the land surface has been constantly changed. Surely they can be at most only a few millions of years old?
But the field evidence suggests otherwise: remnants of very old surfaces are preserved all over Australia. This is not to suggest that such land surfaces have not suffered minor modification since their formation: they have and, in particular, they have been stripped of any soil cover they may have had. But they are still recognisable for what they were: Kakadu was a dissected plateau and there was a Gawler Ranges 120-130 million years ago, Uluru was a (low) hill about 70 million years ago, the Flinders Ranges was a region of ridge and valley topography about 60 million years, and the high plains now evident in many parts of the Eastern Uplands were already in existence more than 100 million years ago; and so on.
Thus some Australian landscape elements are much older than the accepted theory suggests they ought to be. This has serious implications for general geomorphological theory and for the conventional models of landscape evolution.
The occurrence of very old surfaces in Australia is described on a regional basis. How the surfaces have been dated is explained. Brief biographies of some of those who pioneered their recognition and dating accompany several chapters and sections. Factors favouring the persistence of the surfaces are suggested and some of the implications for general theory are discussed.
A Glossary and substantial reference list are provided for those who wish to pursue further detail.
Australia is noted for its old rocks and fossils. Many Australian landscape elements also are very old, and very old plant species have taken refuge and survived in these ancient landscapes. As in so many things, Australia is different.