A 360-million-year-old geological event
The beehive-like domes of the Bungle Bungle Range are composed of Devonian-age quartz sandstone. This rock formed from sediments deposited by ancient riverbeds around 360 million years ago. Tectonic plate movements later lifted this massive block of sandstone to form a plateau. For the last 20 million years, wind from the Tanami Desert and intense seasonal rainfall have been eroding this plateau, carving out the hundreds of conical towers visible today. Some of these domes rise up to 250 meters above the surrounding grasslands.
The range is a example of sandstone cone karst, a landform whose formation is still not completely understood by geomorphologists. The striking orange and black bands are the result of a interaction between water, rock porosity, and microscopic life. The dark grey or black bands are a surface layer of cyanobacteria, some of the oldest forms of life on Earth. These organisms grow on layers of sandstone that have a higher clay content, which allows them to retain moisture for longer. This thin bacterial crust, just a few millimeters thick, creates a protective shield that slows erosion. The orange bands are layers of more porous sandstone that dry out too quickly for the cyanobacteria to survive. On these layers, iron and manganese compounds in the rock oxidize, or rust, staining the surface with its distinct color.
An ancient human landscape
The Bungle Bungle Range is located within Purnululu National Park, a UNESCO World Heritage site covering nearly 2,400 square kilometers. The name Purnululu is the Gija word for sandstone. Aboriginal people have lived in this area for at least 20,000 years, and likely as long as 40,000 years. The Gija and Jaru peoples are the traditional custodians of the park, which contains numerous rock art sites and ancient burial places.
Due to its remote location, the range was not widely known to non-Aboriginal people until 1982. A film crew producing a documentary on Western Australia was alerted to the site by a local pilot and captured the first aerial images, bringing the domes to global attention. The area was declared a national park in 1987 and was added to the UNESCO World Heritage List in 2003. The park is co-managed by the traditional owners and the Western Australian government. The park's ecosystem sits in a transition zone between arid desert and monsoon savannah climates, supporting more than 600 plant species, including isolated patches of rainforest fan palms in its deep gorges. It is also home to at least one endemic lizard species, a small skink named Lerista bungle bungle.