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13 natural rock formations that look man-made

By: Angela Nelson on July 19, 2016, 12:40 p.m.
Wave Rock in Southwestern Australia

Photo: Fredrik Bülow/Wikimedia Commons

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Wave Rock

This well-known landmark in Western Australia was formed 2,700 million years ago, according to the Australian government. At nearly 46 feet tall and 360 feet long, this granite cliff looks like a huge ocean wave about to break.

Wave Rock forms the north side of Hyden Rock, which is a granite inselberg — an isolated rock hill or small mountain that rises abruptly from a flat plain surrounding it — with three domes. The curved face of the cliff has been rounded out over the years through water erosion from two main sources. First, when it rains, inselbergs shed rain water, and the surrounding plains receive the runoff. This causes weathering on the rocks on the sides of the hill and is part of the reason for the concave slope of Wave Rock. Second, as the face of the granite cliff has eroded over the years, groundwater has risen to the surface. That groundwater continuously dissolves and re-deposits chemicals in the granite as it runs down the cliff, resulting in the striped pattern we see today.