The method of verifying the prehistoric mines seems to be to trench a spoil heap and to search for stone hammers and bits of charcoal and charred wood. There is an unmistakeable cist just fifty metres, or so, from the mine entrance and that is a pretty good indicator of a connection. As the mine is slap bank on a riverbank most of the spoil will just have been tipped into it. There are SSSI's downstream that are noted for the strange plants which favour metalliferous shingles. The real test would be an isotope analysis of the slag, allowing the mine to be placed into a context of already found and chemotyped objects. And this mine has only been partially explored - there might be more to find yet ...