A landscape sculpted by deep time
The beehive domes of the Bungle Bungle Range are an example of sandstone cone karst terrain. The story begins around 360 million years ago, during the Devonian period, when rivers deposited sand and gravel into a basin. Over millions of years, these sediments were compressed into a massive plateau of quartz sandstone. Tectonic forces later lifted this plateau, and for the last 20 million years, erosion has been the primary force at work.
The sandstone itself is extremely fragile. Torrential wet-season rains and winds have carved deep chasms and gorges, sculpting the soft rock into the famous dome shapes that rise up to 250 meters (820 feet) above the surrounding plains. This ongoing process of weathering and erosion means the landscape is constantly, if imperceptibly, changing. Within the park, a 7-kilometer diameter circular feature, known as the Piccaninny Circular Structure, is believed to be the eroded remnant of a meteorite impact crater.
The biology of the stripes
The striking orange and grey bands that give the domes their tiger-striped appearance are the result of a complex interaction between geology and biology. The bands are a surface stain and a living ecosystem. The dark grey or black bands are biological crusts composed of cyanobacteria, some of some of Earth's oldest life. These single-celled organisms grow on layers of sandstone that have a higher clay content, which allows the rock to retain moisture. This thin microbial layer, only a few millimeters thick, stabilizes the fragile sandstone surface and protects it from erosion.
The bright orange bands are layers of sandstone with less clay. These layers are more porous and dry out too quickly for the cyanobacteria to establish a colony. Their color comes from oxidized iron compounds, essentially a form of rust, staining the rock. This combination of microbial growth and mineral staining creates the distinctive, alternating pattern that makes the Bungle Bungle Range geologically and biologically unique.