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The Pinnacles Desert is located a little south of the town of Cervantes on the west coast.
It is part of the Nambung National Park and while the pinnacle structures are by far the most famous part of the park, there is also Lake Thetis that contains some of the oldest living organisms known to science.
These organisms are known as stromatolites and are estimated to have existed on Earth for 3,500 million years. They are not the most interesting life forms to observe but as Bill Bryson once said, "it's not the sight of stromatolites that makes them exciting. It's the idea of them".
Lake Thetis has been isolated from the sea for about 4,800 years. The highly saline lake is an ideal environment for the stromatolites. A boardwalk at the lake allows visitors to get close to the endangered stromatolites without disturbing them or damaging them in any way.
The pinnacles were once thought to be the remains of an ancient city and may have appeared on Dutch maps as early as 1658. There are about 150,000 individual structures.
The pinnacles are the fossilised remains of a forest that now jut from the sandy soil. There is some disagreement among scientists about exactly how the formations occurred, but a general consensus seems to be that minerals soaking down into the decaying root systems and holes left by large tree roots led to these spectacular outcrops.
The DEC Nature-base website gives the following information about the formation of the Pinnacles:
'The raw material for the limestone of the pinnacles came from sea shells in an earlier epoch rich in marine life. These shells were broken down into lime-rich sands which were brought ashore by waves and then carried inland by the wind to form high, mobile dunes. Three old systems of sand dunes run parallel to the WA coast, marking ancient shorelines.
The oldest of these, known as the Spearwood dune system, is characterised by yellow or brownish sands. In winter, rain, which is slightly acidic, dissolves small amounts of calcium carbonate as it percolates down through the sand. As the dune dries out during summer, this is precipitated as a cement around grains of sand in the lower levels of the dunes, binding them together and eventually producing a hard limestone rock, known as Tamala Limestone.
At the same time, vegetation that became established on the surface, aided this process. Plant roots stabilised the surface, and encouraged a more acidic layer of soil and humus (containing decayed plant and animal matter) to develop over the remaining quartz sand.
The acidic soil accelerated the leaching process, and a hard layer of calcrete formed over the softer limestone below. Cracks which formed in the calcrete layer were exploited by plant roots. When water seeped down along these channels, the softer limestone beneath was slowly leached away and the channels gradually filled with quartz sand. This subsurface erosion continued until only the most resilient columns remained. The Pinnacles, then, are the eroded remnants of the formerly thick bed of limestone.
As bush fires denuded the higher areas, south-westerly winds carried away the loose quartz sands and left these limestone pillars standing up to three and a half metres high.'
The Aboriginal name for the area 'Nambung' means winding or crooked and refers to the river running through the park.
In the late 1880s a stock route from Dongara to Perth passed through the area and in the early 1900s local farmers mined bat guano from caves.
James Mitchell (later Governor Mitchell) visited the caves and was so impressed with what he saw that he led efforts to have most caves on the south coast protected by law.
The first areas in the park to be protected were around the Nambung River in 1956. This was later added to and the National Park was created in 1968.
If you are visiting the park with your caravan or camper trailer in tow, then be prepared to drop the van off in the parking area if you want to drive around the 4 kilometre road through the park. If you don't want to un-hitch your van then you have to take the 1.2 kilometre walk trail.
Other attractions in the park are found only by those prepared to walk. Vehicle access has been deliberately restricted and walking is the only way to see many areas of the park. If you decide to explore this area on foot be aware that it is 'tick country'. Careful self examination is advised when you return from your explorations to remove any ticks that may have attached themselves.
Other attractions in the area include Kangaroo Point, Hangover Bay, Coloured Desert as well as the variety of plants and animals that live in the area.
An interesting book on the creation of the National park was written by the first Ranger to work there. 'Nambung Here We come' by A. Passfield.
NPW Website for more information
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