What Rock Is Uluru Made From?
Uluru is a massive red rock centred in Australia’s Red Centre in the Northern Territory. The famous landmark became a UNESCO World Heritage Site in 1987, and is cherished by Indigenous Australians. Uluru has gained widespread popularity across the globe, attracting thousands of visitors each year, travelling from far and wide to witness this natural phenomenon with their own eyes. The fascinating rock is over 500 million years old, deeming it 250 million years older than dinosaurs!
You can find Uluru in the Uluru-Kata Tjuta National Park, 460 kilometres from the remote town, Alice Springs. The National Park is on the land of Australia’s Traditional Owners, the Anangu people. For thousands of years, the local Anangu people have inhabited this area, holding spiritual bonds with Uluru and its surroundings.
What type of rock is Uluru?
Uluru is Australia’s largest rock formation and is made up of coarse grained sandstone, known as arkose. Arkosic sandstone is a sedimentary rock classified by its high feldspar composition (25%). Feldspar is a group of aluminosilicate minerals that are among the most abundant in the earth’s crust. You can find arkosic sandstone in different corners of the world. The Rocky Mountains in North America, the Alps in Europe, and the East African Rift are all places where arkose has been discovered.
Uluru is often classed as a monolith, a standalone rock that has been exposed above the surface of the earth. However, geologists would argue that Uluru is an inselberg, an isolated mound that rose abruptly due to erosion.
How was Uluru formed?
500 million years ago, the land where Uluru stands was actually an inland sea, known as the Amadeus Basin. Over time, sand and mud fell to the bottom of the seabed which eventually turned into a large pile of arkosic sandstone. Eventually the sea dried up, the rocks tilted as the earth’s tectonic plates moved, leaving a mountainous rock the size of the Himalayas behind. Without the help of plants, roots and soil to help hold the rock together, it began to erode leaving what we now know to be Uluru. Today, Uluru stands 348 metres tall (taller than the Eiffel Tower), 1.9 kilometres wide and 3.6 kilometres long. Most of Uluru’s mass is actually beneath the surface. In fact, the large rock continues to stretch underground for 2.5 kilometres!
Why does Uluru look smooth?
The reason Uluru appears smooth is due to the fact it was underwater for thousands of years. As the Amadeus Basin evaporated, it caused the sandstone to erode and soften. When you look closely at Uluru, you will see that the surface is made up of flakes of red rock, remnants left behind as minerals in the rock decayed due to water and oxygen exposure. On the northern side of Uluru, weathering and rainwater has created parallel raised ridges outlining the sedimentary layers which you can see.
What makes Uluru so red?
Uluru wasn’t always red, its original colour was grey. In fact, if you were to explore Uluru’s caves nestled within the rock, you will discover that the grey surface remains. As Uluru was underwater, it was starved of oxygen. So when the inland sea drained over thousands of years, the arkosic sandstone was exposed to the air. This created a chemical reaction between the high contents of iron within the rock to rust when it was exposed to oxygen, leaving behind the red colour we see today. The process is similar to if you left your bike outside for a long period of time, it will rust.
If you look at Uluru throughout the day, you will notice that the colours appear to change. This is a result of the mineral composition in the rock. When the sun moves throughout the day, it reflects rays onto Uluru from different angles. These rays rebound from the ground to the rock, creating the illusion of colour change.
Can I climb Uluru?
As of October 2019, climbing Uluru has been banned. Uluru is a sacred place for the local Anangu people who are the Traditional Owners of the land. For years, the Anangu people were pleading with tourists to stop climbing the rock, before it became illegal. Uluru has been a significant landmark to the Anangu people since the beginning of time. They believe the rock was formed during the Dreamtime and remains a resting place for ancient spirits in the region. Today, ceremonies are held by the local tribes in the sacred caves nestled within Uluru.
Years of climbing Uluru has caused erosion which has changed the surface of the rock. The arkosic sandstone is fragile and climbing has caused the rock to wear and erode. Uluru is steep which proves to be dangerous for anyone scrambling along. People have been severely injured, stuck, suffered heat exhaustion or rescued from Uluru. Weather patterns also rapidly change the conditions of the rock deeming it unsafe to climb.
How can I visit Uluru?
If you’re planning a trip to the remarkable Uluru, we offer numerous tours. Although you are permitted from climbing the rock, there are plenty of ways of seeing the rock up close. Hot air balloon rides, scenic flights, bike and camel tours are among the many tours available. Chat to our team of experts today who will hook you up with the hottest deals to visit this iconic destination!
