Uluru was formed about 550 million years ago during the Cambrian period when central Australia was largely covered by a shallow sea. Layers of mineral-rich sand and mud were deposited on the ocean floor, which over millions of years compressed and hardened into sandstone, primarily arkose. Geological events, including the Petermann Orogeny—an ancient mountain-building episode—caused uplift and erosion. The sandstone layers were tilted almost 90 degrees upward due to tectonic activity around 400 million years ago. Over the subsequent millions of years, softer surrounding rocks eroded away, leaving the harder sandstone rock of Uluru standing prominently as a monolith. Its characteristic reddish-orange color results from oxidation (rusting) of iron-bearing minerals on its surface. The rock extends both above and significantly below the ground, similar to an iceberg. This natural formation process was further shaped by erosion from wind, rain, and temperature changes, creating its present smooth and rounded appearance.
