The Devil’s Playground

As we crossed the border into Northern Territory we were overcome by how huge this country is! We drove for days along the same road and saw nothing for hours at a time. The landscape subtly changed into the dry dessert of Central Australia.

 

 

Changing our clocks back, we arrived at Barkley Homestead, exhausted and hungry. A quick dip in the pool was very refreshing and a trip to the pub filled our bellies. A load of laundry the next morning (which dried in about 30 minutes!) and we were ready to hit the road again.

 

 

The road from Barkley Homestead to Three Ways, was the longest and straightest we had ever driven on. We were surprised by the lack of wildlife (both living and dead) and figured it was too dry and hot out here for even them.

 

Along the way we saw giant plumes of smoke on the horizon. As we got closer, we realised that the locals were undertaking controlled burning of the undergrowth. Driving past, we could feel the heat of the fires through our car windows, and chills went up my spine at the thought of being trapped out here in a bushfire.

 

 

 

We stopped at Tennant Creek to fill up with fuel and beer and headed to the Devils Marbles Nature Reserve. The site is known as Karlu Karlu to the land's Aboriginal traditional owners. The ‘Devils Marbles’ or ‘Karlu Karlu’ with its gigantic, rounded granite boulders, some spectacularly poised, is a remarkable landscape. Scattered clusters of these ‘marbles’, including many balancing rocks, are spread across a wide, shallow valley. 

The Devils Marbles are made of granite, which surfaces like a little geological island in the desert, surrounded by large amounts of sandstone. The granite was formed millions of years ago as a result of the hardening of magma within the Earth's crust. Thick layers of sandstone on top of it put a lot of pressure on this granite. After the folding of the Earth's crust, which lead to the lifting of the granite and the erosion of the sandstone, the granite came to the surface. The pressure was gone, letting the granite expand; cracks formed, and it fell apart in big, square blocks.

The second phase of the formation of the Marbles started when the blocks were exposed to water. The surface of the blocks began to decay under the influence of the water, and a layer of loose material surrounded the individual blocks. When they came to the surface completely, this layer was flushed away by water and blown away by wind.

The rounding of the granite blocks is a result of both chemical and mechanical weathering. Firstly, exfoliation plays a part. Chemical processes cause the surface of the blocks to expand and/or shrink. Thin layers of rock come off the boulder. This rounds the granite block, because the chemical processes have more effect on areas with edges. These processes cause the rock to look like it is made of layers like an onion. In effect, only the outer few centimetres are affected by chemical weathering. This process is called spheroidal weathering. Secondly, the boulders are suffering from solarisation. Because the temperature differences between day and night are so great, the rocks expand and shrink a little bit every 24 hours. This causes some rocks to crack, sometimes even splitting them in half.

 

 

 

Another long drive today and we will arrive in Alice Springs where we will spend the next few months. I don't know what to expect from Alice Springs as I have heard many different stories from lots of people. We have got an interview with the Steiner School to see if they will accept the boys for next term, which will give me a well-deserved break from playing teacher-mum, and give me some time to play one-on-one with Zaccy.