The structure of the valley is split, with Upper Wharfedale consisting of carboniferous limestone of the Yoredale series. Yockenthwaite, Upper Wharfedale. (Pic credit: Bruce Rollinson) In the ...

This time period took place 359 to 299 million years ago. 3 min read The Carboniferous period, part of the late Paleozoic era, takes its name from large underground coal deposits that date to it.