Moeraki boulders, New Zealand. These boulders are examples of structures known as septarian concretions, a form of hard sedimentary rock that is usual

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Moeraki boulders, New Zealand. These boulders are examples of structures known as septarian concretions, a form of hard sedimentary rock that is usually spherical in shape. As the surrounding, softer, rock is eroded away, the concretions are left behind, as seen here. It is thought that these concretions formed some 60 million years ago. They weigh several tonnes and can be 3 metres across. Photographed in Moeraki Boulders, Moeraki, South Island, New Zealand.

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Size: 3425px × 5138px
Photo credit: © CHRIS MARTIN-BAHR/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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