The Purnululu National Park

The Purnululu National Park occupies almost 240,000 hectares of Western Australia and is a stunning example of nature at its finest. The park has become internationally renowned, in part due to large sandstone formations, commonly known as the Bungle Bungle range. You would think that knowledge of formations like this would be widespread, yet the area has only recently been discovered and exposed to the wider world.

Although indigenous communities have roamed the area for over 20,000 years and understand and respect the area, it wasn't until 1982, when aerial photography captured the formations, that the beauty of the Bungles was revealed to the world. As scientists, we were extremely excited about this new- found location and were keen to explore. Around 20 years later, in 2003, the site was rightfully classified as a World Heritage Site, meaning that we could protect and conserve the area. The main features of the Bungles are the magnificent dome-shaped formations made from sandstone. Other sandstone formations have been found all over the world, and in other parts of Australia, but the Bungles are truly remarkable.

The main reason why these particular sandstone formations are incredible is because they are the best example of beehive-shaped, natural structures anywhere in the world. The sheer expanse of them remains unsurpassed, while their colours and ecological features are unrivalled. What we are not completely certain about is how exactly they were formed, although we estimate that they began forming around 350 million years ago and that they were part of a riverbed, with layers that were created over the millennia. We know that they have been weathered and eroded by water as well as wind to create their impressive shapes, but their exact formation remains a mystery.

The structures are an extremely important scientific discovery, as they highlight the process of their formation, even though we have yet to fully understand it. In fact, we have only recently discovered the effect of dome formation on sandstone. What we can see is evidence of the effect that ecology, biology, erosion, and climate have on sandstone and this iS something we will be investigating for many years to come. The Bungles are unique in their range of diversity, so there is a vast amount of research to be completed.

The colours of the structures are outstanding. The striking orange and black pigments have become characteristically part of the Bungles' charm. When the iron in the sandstone oxidises, it creates the stunning orange colour that can be seen, in what is called the 'rusting process. This part of the rock is liable to dry out more quickly because it has less clay content, which means that bacteria which protect it from oxidisation cannot grow properly. In contrast, some of the layers are dark; these areas contain more clay, which retains moisture, meaning the bacteria can protect these layers from erosion and oxidisation. However, possibly the most exciting thing about the colours is the changes they undergo in different lighting conditions. Rays from the sun hit the rocks at different angles creating a variety of hues which are just astonishing. Add in the shadows created by the sun and the spectacle is truly amazing. The notorious wet season in the area helps to fill the pools and power the waterfalls dotted around, making for a stark comparison between the rock colours and bright skies.

Since the creation of the World Heritage Site at Bungles, there has been a rise in the number of visitors to the area, and this needs to be carefully managed. Management of the park is shared between the Western Australia Department of Environment and Conservation and the local, indigenous people. It is essential that the land is co-managed in this way, so as to repect the culture and traditions of the people who know the area best. It would be a travesty if control were taken away completely.

Although welcoming visitors to the area is to be encouraged, it is vital that the land is protected and shielded from any environmental impact from tourists. The Bungles are in a relatively remote location and remain fairly inaccessible, which means that many tourists take to the skies in helicopters to observe the formations instead of walking. This, in fact, is probably the best way to see the Bungles. Travelling by air means less of an impact on the ground so the fragile sandstone structures and the land surrounding them are preserved.

The management of relatively low tourist numbers has so far been effective in keeping conservation levels at a stable rate. A recent conservation report recorded that the threat level to the area remains low, but this does not mean that management can be complacent. There may not have been any decline in the geological value of the site, but there are still threats that pose risks to the scientific and cultural heritage on offer at the Bungles. Some of the threats to the land include fire and invasive species, in addition to the environmental impact from tourists. Indeed, in 2016, a fire ripped through a large area of the Purnululu National Park, burning tens of thousands of hectares of land and leading to the temporary closure of the park to tourists.

The importance of the Purnululu National Park and the Bungles cannot be underestimated, yet as we study it and learn about their formation, we must preserve the cultural heritage by encouraging sensitivity towards the indigenous culture, traditions, and knowledge which have kept the area safe for over 20,000 years.