Folding a Mountain

Folding a Mountain

Mountains can be formed in many ways. Some form when lava spills from a volcano, and piles up on Earth's surface as it hardens. Others form when pieces of Earth’s crust pull apart from one another, a process called "rifting." Most commonly though, mountains form when tectonic plates collide, folding and pushing layers of land into mountain ranges. The Flinders Ranges—the largest range in South Australia—is a classic example of a folded mountain range.

The many curves and folds of the Flinders Ranges are visible in this image, which the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired on April 12, 2019. The range spans 430 kilometers (270 miles), with nearly all the peaks exceeding 300 meters (1,000 feet). One of the most notable features is the Wilpena Pound, an orange-tinted sandstone valley surrounded by high rock walls. The mountains are surrounded by low-elevation flat lake systems such as Lake Frome and Lake Torrens, which drain from rivers in the Northern Flinders Range.

The Flinders Ranges began forming about 800 million years ago, when an ancient sea deposited sediments in a basin known as the Adelaide Geosyncline. Around 300 million years later, the basin sediments were folded into mountains during an orogeny, or mountain-building period. The mountains have since eroded. However, the folded and faulted rocks remained and were uplifted in the last five million years to create a rugged landscape filled with sandstone, mudstone, limestone, and quartzite.

The region is known for more than its rocks and rugged look. The Northern Flinders Range is home to a community of around 66 indigenous Adnyamathanha people in the town of Nepabunna. Established in 1931, Nepabunna is the tribe’s first permanent settlement since being displaced from their traditional lands by Europeans in the 1850s.

The Nepabunna community has played an important part in revitalizing their ancestral lands. In 1987, the community received back more than 58,000 hectares (140,000 acres) of their historical Adnyamathanha land in the region from a pastoralist. Over the past 20 years, the Nepabunna community restored the site—known as Nantawarrina—by replanting native vegetation, preserving native animals such as the yellow-footed wallaby, removing feral goats from the area, and adding activities to promote tourism. The Nepabunna community was recognized for their excellence in management of their lands by winning the International Union for Nature Conservation Award.

Nantawarrina was Australia’s first Indigenous Protected Area; there are now 75 of them covering 67 million hectares, many situated near Australia’s most fragile environments.

NASA Earth Observatory image by Lauren Dauphin, using MODIS data from NASA EOSDIS/LANCE and GIBS/Worldview. Story by Kasha Patel.

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