There has been a recent upsurge in research into structural geology and sedimentology of Wales. The breadth and the quantity of the activity, particularly in previously under-researched areas, is reflected. Chapters are arranged in approximate time order of the events described and new field data are set in their local tectonic context. Speculation on models for the plate tectonic setting of Early Palaeozoic Wales is included, with an examination of the necessary components. This book is based on material presented at a joint meeting of the Tectonic Studies Group and the British Sedimentological Research Group of the Geological Society of London, held at the University College of Wales, UK in April 1986.