If a Marine terrace is just a reised beach why would it be hard to find them? Wouldn't it look the same as a beach, with sand and shells?
That is a good question and it would probably, at least at first, look just like that! But by the time that it has been raised for even 100 years, let alone 1000-2000 years, it gets covered with vegetation and then soil begins to form. Occasionally, in the Kurils especially, a volcanic eruption might cover it with tephra, ash or other volcanic debris. Then more vegetation would grow on top of that, etc. So by the time that we see it, the original sandy beach layer could be a meter or more below the surface. That is one of the ways that the geologists identify the marine terraces, by their shape and by digging down to find the marine sand, cobbles or other beach material. Generally the number of shells on the beaches are not very numerous, so finding any in one small hole could be difficult.
Thanks for the question!
Mrs. N-O
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