Purnululu or “The Bungle Bungles” – The South

March 17, 2014graeme@churchard.com

 28th to 30th August 2013

The southern part of the National Park is famous for the stripy domes. These had been known to the local population and occasional visitor for many years but were unknown to the outside world until sometime in the 1980′s when a film crew flew over and released a film which became, in modern terms, “viral”. Within ten years it was a National Park and in twenty it was a World Heritage Site.

Visiting the area lets you know that it deserves its status!

HERE is yesterday’s route with photos. Open with Google Earth. Part of it concerns the south of the Bungles.

Here is a map of places we visited.

Bungle geol29
Places visited in the south of the Bungle Bungles

In the late afternoon of Wednesday the 28th we drove to the southern part of the range to get a first glimpse of the stripy domes and found them at their best in the evening light.

The Domes Walk
Stripy domes of the Bungle Bungles

They are all around.

The Domes Walk
More stripy domes

What is the cause of the stripiness? A close look at the rock shows that it is a surface phenomenon.

The Domes Walk
A close up of the stripes

The red colour is easily explained – most of Western Australia is iron stained! Rain falls on the rocks and soaks in. It dissolves some of the iron oxide in the rock. The sun comes out, dries the rocks and the water with dissolved iron oxide comes to the surface. The water is evaporated, the iron oxide is left on the surface. It doesn’t take much iron oxide to give a very noticeable red crust.

The black or grey colour is less easily explained. Careful examination of the sandstone shows that it is not uniform. Some layers have slightly more clay content so when the sun shines after rain they stay damp for longer. And this encourages cyanobacteria to grow and this is black in colour.

So the red stripes are fairly pure sandstone; the black stripes are sandstone with some clay minerals.

The red and black crusts protect the sandstone from weathering and erosion when the rock layers form cliffs but not when they are horizontal. You can see this in the next photo; all the rocks are white sandstone but only the cliff faces are stripy.

On Thursday we returned to the south.

HERE is today’s route with photos. Open with Google Earth.

Around Whip Snake Gorge
Chris walking along the bed of the Piccaninny River

But there is more to see than just stripes – there are multi storey termite nests!

The Domes Walk
Termites nest climbing a stripy dome

We also walked into Cathedral Gorge which is a rather wide gorge with an overhang and pool at its head.

Cathedral Gorge
Cathedral Gorge

We also walked along the Piccaninny River to Whip Snake Gorge. As a gorge it is rather disappointing – we had been spoiled by the gorges of the previous day but scenery of the walk was breath taking. The temperatures of the walk were also breath taking – the white sandstone of the river bed reflected the heat and temperature were into the mid forties!

Around Whip Snake Gorge
View on the way to Whip Snake Gorge

The next day – Friday 30th August we drove to Lake Argyle. I drove the first bit and was able to get from the Ranger Station to the main road in five minutes less than Chris took. I just thought I would mention that.

HERE is today’s route with photos. Open with Google Earth.

It was on the Great Northern highway, heading north from the Bungle Bungles, that we had our nearest approach to an accident. Chris was driving and we were on a long bend with a big road train coming towards us. Then we noticed a 4×4 on our side of the road coming towards us! Most unexpected. Chris slammed on the brakes and steered for the side of the road. The idiot must have had his guardian angel watching as he squeezed between us and the front of the road train. It reminded us never to pass a road train on a bend.

We stopped at Kununurra to get some provisions and then carried on to the Lake Argyle camp site.