A Mountain Range Turned Inside-Out
From the air, Wilpena Pound looks like a colossal meteorite crater. It is a geological feature known as a synclinal basin, the remnant of mountains that have eroded over hundreds of millions of years. The structure is located in the Ikara-Flinders Ranges National Park, about 429 kilometers north of Adelaide. Its oval-shaped ring of mountains stretches approximately 17 kilometers long and 8 kilometers wide, enclosing a basin of nearly 80 square kilometers.
The story of the Pound begins over 800 million years ago, when the area was a shallow sea. Layers of sediment accumulated on the seafloor, which were later compacted into sedimentary rock. Around 500 million years ago, tectonic forces buckled and folded these rock layers, creating a massive downward fold called a syncline. The result was a mountain range once thought to be taller than the Himalayas.
The Pound's formidable walls are composed of Rawnsley Quartzite and Bonney Sandstone, extremely hard rocks that are resistant to weathering. The rock layers that once covered the center of the syncline were softer and more easily eroded. Over millennia, wind and water scoured away this softer material, leaving the hard quartzite rim is a, fortress-like enclosure. This process of differential erosion created the amphitheater we see today. The floor of the Pound is actually about 200 meters higher than the surrounding plains, making it a raised basin.
Deep Time and Human History
The highest point on the Pound's rim is St. Mary Peak (Ngarri Mudlanha), which at 1,171 meters is also the tallest peak in the entire Flinders Ranges. For the Adnyamathanha people, the traditional owners of the land, this landscape is a place known as Ikara, meaning "meeting place." Their Dreaming stories explain the creation of the Pound as the work of two giant serpents, or Akurra, whose petrified bodies form the encircling walls. Archaeological evidence shows continuous occupation of the region for at least 49,000 years.
The rock that forms the Pound is part of the Pound Subgroup, a geological formation famous for containing fossils of the Ediacara Biota. These fossils, found in the nearby Ediacara Hills, are some of the earliest known complex multicellular life on Earth, dating back to roughly 555 million years ago.
In the late 19th and early 20th centuries, European settlers attempted to use the Pound's naturally enclosed landscape. The Hill family established a farm inside the basin in 1899, growing wheat with some success. However, a devastating flood in 1914 destroyed their road through the narrow Wilpena Gap, forcing them to abandon the farm. The stone homestead still stands inside the Pound today.