Uluru / Ayers Rock, Northern Territory, Australia

Uluru / Ayers Rock is a massive rock structure located in Northern Territory, Australia. Consisting of red sandstone that is relatively resistant to weathering, Uluru / Ayers Rock prominently rises 348 meters above the surrounding lowlands. The structure has likely been formed by sediment deposition in alluvial fans associated with mountain uplift during the late Neoproterozoic to early Cambrian (~ 550 million years ago), followed by tilting in the Paleozoic (~ 400 million years ago). Subsequent erosion of the surrounding rocks and the formation of iron oxides further shaped Uluru / Ayers Rock into its present state as a majestic red mountain.

Information source: Uluru-Kata Tjuta National Park Service

Image: Uluru / Ayers Rock at sunset in Northern Territory, Australia. Credit: Weyf, Wikimedia Commons.

The Wave, Arizona, USA

The Wave is a rock formation in the Colorado Plateau of Arizona in the United States that was formed by erosion of the Jurassic Navajo Sandstone. It is known for its many undulating structures and contains large sets of cross bedding in aeolian sandstones, which reflect the migration of sand dunes and ripples across an ancient desert environment. The cyclically alternating laminae seen in the Wave result from periodic changes in the prevailing wind directions at the time of deposition.

Information source: Vermillion Cliffs National Monument Service

Image: Cross-bedded aeolian sandstones of the Wave in the Colorado Plateau of Arizona, USA. Source: Sehara, Wikimedia Commons.