Tafoni BasaltThis is a lovely rock from Rapa Nui (aka Easter island). Like many of the rocks on that

Tafoni BasaltThis is a lovely rock from Rapa Nui (aka Easter island). Like many of the rocks on that hotspot-produced island, this rock is a basalt, a lava flow erupted from an oceanic volcano. You can also clearly see how the outermost layer of the rock is being gradually popped off – this honeycomb like texture is called “Tafoni” by geoscientists.There is no single, exact mechanism that produces this type of weathering every single time. In most cases, it is found associated with salts and water, but wind erosion and maybe even bacteria can play a role. The most general idea is that it is associated with wetting and drying of the rock surface; a little sea spray brings in some salt, as the water dries out that salt is left behind, and as salt crystals grow they gradually put more pressure on the grains that surround them, eventually causing the grains to be shoved out of the way.-JBBImage credit: https://flic.kr/p/2jqxVH3Reference: https://onlinelibrary.wiley.com/doi/abs/10.1002/esp.2112 -- source link
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