The landscape

Central Australia can be daunting. Early on, several ill-equipped European explorers set out never to be seen again. This is perhaps where Central Australia got the nickname 'The Never Never'. Even today people can 'do a perish' if they breakdown off-road and have insufficient water.

This extremely ancient landscape was just as harsh when the first people arrived as it is now.

Yet people have made this environment home for tens of thousands of years (see When did people arrive in Australia? - 2017 Addendum - on this website).

 
George Gill Range - location of Kings Canyon - from the helicopter

The present Australian continent was once part of the landmass known as Gondwana, located at the South Pole.

Between 900 million and 300 million years ago a large depression in the Earth's crust here filled with layer upon layer of alluvial deposits: sand eroded from volcanic mountains. These sands were compressed to form sandstone layers of different density and particle size, some much more resistant to weathering than others.

Towards the end of this period the underlying crust began to disrupt the once horizontal sedimentary layers so that they tilted and deformed. In some places these became steeply sloped or vertical, forming the mountains, of which the various Central Australian prominences, the MacDonnell Ranges; Mount Conner; Uluru (Ayers Rock); and Kata Tjuta (The Olgas) are eroded remnants (see: Formation of Uluru and Kata Tjuta).

Thus, Uluru is the eroded tip of an almost vertical seam of hard arkose sandstone (the small rectangle to the right in the above graphic) that extends as much as six kilometres below the surface. A similar process formed the nearby Olgas (Kata Tjuta - the small rectangle to the left in the above graphic) although they consist of a coarser yet similarly hard-weathering sandstone. During these eons the Earth went thought cycles of glaciation and warming, eroding the ancient mountains and re-layering the valleys.

Until about 500 million years ago life on earth was single-celled, there were no multicellular plants to slow erosion and, of course, no multicellular animals to dig or trample.

The first terrestrial plants evolved from simpler organisms. The mostly nitrogen atmosphere then contained much more carbon dioxide and very little oxygen but photosynthesis in algae and then plants reversed this and during a hundred million years or so and, to cut a long story short, complex animals evolved to eat the plants; and each other.

Some of these got bigger and bigger until the age of the dinosaurs about 150 million years ago. Throughout these eons the oxygen in the atmosphere began to oxidise the many metals thrown up from the core and mantle by eruptions (except for gold that remained unoxidised). Principal among these metals was iron, of which the core mainly consists. So, with free oxygen, the Central Australian landscape went from grey, like the moon, to the red we see today, due to these iron oxides.

About 85 million years ago the continent that is now Australia, together with South America, began to separate from Antarctica and move north. This drift still continues now at a rate of about 7 cm a year and causes earthquakes and volcanoes in New Zealand where the Australian plate rubs against the pacific plate.

65 million years ago there was a mass extinction event, probably a meteor impact, when the dinosaurs, that once abounded here, together with many other animals, were all but wiped out; save for some smaller survivors like crocodiles and birds, setting the scene for the rise of the mammals, our ancestors.

About 30 million years ago Australia was fully separated from Antarctica.

At that time the planet was a lot warmer and largely ice free and sea levels were a lot higher. So, part of the new continent of Australia was below sea level and much of central Australia was under the ocean. Elsewhere great coniferous forests grew, converting carbon dioxide to oxygen, the carbon thus captured, eventually to be laid down as the rich coal deposits, now found in parts of eastern Australia.

But central Australia remained distant from the plate boundaries with their tectonic disruptions; folding; and vulcanism. As a result, almost all the landscape here consists of ancient sedimentary rocks. Some are so dense that early explorers thought them to be igneous (volcanic) or metamorphic. The underlying rocks are overtopped with the erosion products: coarse, often salty, and relatively infertile sand. Nevertheless, some plants thrive and there is a surprising variety of hardy grasses and many different and beautiful wildflowers.

Before humans evolved from earlier primates, a million or so years ago, and then some of our ancestors migrated here, perhaps 65 thousand years ago, other creatures including giant marsupials, roamed.

There is now good evidence that the first humans hunted the megafauna they found when they arrived, probably leading to their extinction (see When did people arrive in Australia? - Australian Megafauna - on this website).

Despite the preponderance of coarse grasses and scrubby trees we saw no native grazing animals. At Uluru we were told that there are no large kangaroos as it is too dry. But we saw many small lizards and lots of ants; flies; and other insects; that presumably feed the many birds, including stately raptors, like eagles and kites, like the Whistling Kite at the top of the page.

Alice Springs is noticeably more verdant than Uluru; but if Europe is a fifty The Alice is a five.

The Dingle Peninsular in Ireland and Alice Springs
No doubt a bit of a shock to those immigrant Irish stockmen like Clancy

We were told of larger lizards and snakes but our various, quite long, walks were on established paths. These are defined by the National Park to avoid damage to the fragile landscape, so no doubt these rather shy creatures, as did Clancy, prefer to avoid 'the ceaseless tramp of feet'.

But at Kings Canyon we did see a dingo (without a baby); some captive emus; and nearer to Alice Springs, a number of brumby horses and some wild cattle. There is also a camel farm at the Uluru (Yulara) Resort.

The winter climate took us by surprise. It rained lightly on several occasions, both at Uluru, where the setting sun created an amazing rainbow with its end right over the rock, and less spectacularly at the West MacDonnell Ranges.

Uluru Rainbow

It was cold. Daytime temperatures seldom rose above 20C. After dusk the temperature fell to half this and we were thankful for our down jackets and warm hats and gloves; still needed until the sun was well up in the morning. We were told by locals that this was unusually cold for June. In summer it's quite different. Daytime temperatures well over 30C are not unusual.