This memoir describes the geology of part of the Welsh Borderland. Precambrian and Ordovician rocks of the Shelve crop out in the north but Silurian rocks under

The Ordovician was one of the longest of the geological periods, characterized by major magmatic and tectonic activity, an immense biodiversification, swings in

This second edition of 'The Geology of England and Wales' is considerably expanded from its predecessor, reflecting the increase in our knowledge of the region,

&Quot;This Report is revised and expanded from the 1972 publication, providing an up-to-the-minute account of the British Ordovician formations and their correl