I've been having a bit of a browse on the Museum of Wales Minearology database. I was vaguely aware of Glasdir Turf Copper etc, but not really aware of the porphory copper that it was derived from. All this appears to be based on Afon Wen, and its fault and intrusion. So, any hints for a Friday afternoon mooch? Not this Friday though, one for when summer gets it's act together.
Cheers, Robin