Yes, it is difficult to know. I have read that larger adult shells can survive for over a hundred years on a beach – maybe that is because they get buried part of the time and therefore are not always subject to weathering and wear. The coarse shell sand shown in the photographs probably represents a transition phase towards the much finer fragments that eventually get caught by the wind and transported further inland to form the dunes and cover the common on the northern end of the island.
I find it fascinating to try and imagine how long it took to create such a beach!
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Yes, it is difficult to know. I have read that larger adult shells can survive for over a hundred years on a beach – maybe that is because they get buried part of the time and therefore are not always subject to weathering and wear. The coarse shell sand shown in the photographs probably represents a transition phase towards the much finer fragments that eventually get caught by the wind and transported further inland to form the dunes and cover the common on the northern end of the island.
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