Columnar basalt, near East Dam on High Island Reservoir, Sai Kung, Hong Kong, China. Columnar basalt forms during the cooling of a thick lava flow. Th

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Columnar basalt, near East Dam on High Island Reservoir, Sai Kung, Hong Kong, China. Columnar basalt forms during the cooling of a thick lava flow. The light-coloured hexagonal basalt columns in Hong Kong have a unique composition, different from the generally dark grey columns found elsewhere in the world. The composition includes rocks such as rhyolite and dacite with a porphyroclastic texture, rich in potash feldspar and quartz phenocrysts. The columns date from the Early Cretaceous, and are part of the Kau Sai Chau Volcanic Group. They are also part of the wider Hong Kong Global Geopark of China.

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Size: 5138px × 3425px
Photo credit: © TIM LESTER/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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