Full Description

The hypothesis that tectonism exerted a major influence on sedimentation in the British Isles during the Devonian an Carboniferous has been advanced by many geologists and is widely accepted. Controversy, however, exists regarding the extent, style, mechanism and exact timing of this tectonism. A large number of models and variants of models exist, from a local to the plate tectonic scale.

Syn-sedimentary tectonism is not the only hypothesis which has been proposed to explain variation in the Devonian and Carboniferous rocks of the British Isles. Sedimentary and climatic processes and eustatic changes in sea level have also been proposed. In some cases these various hypotheses have been invoked for the same set of rocks by advocates favouring one or two theories over the others.

Of the various main hypotheses, those on syn-sedimentary tectonism appear to be the most amenable to testing, utilising recent advances in geological techniques, particularly in sedimentology, basin analysis and biostratigraphy. By determining the style and timing on syn-sedimentary fault movements and local crustal tilting and warping, further light might be shed on the possible controls invoked by other hypotheses.

Papers include case histories from Ireland, England, the Midland Valley of Scotland and South Wales: studies taking sedimentary basins as a whole and examining the interaction of sedimentation, subsidence and deformation during their evolution; and larger-scale discussions on the tectonic setting of basin development during the Devono-Carboniferous. Additionally, two papers, citing case histories from the Carboniferous of northern England, were concerned with the problems of distinguishing the effects of tectonism from those due to other influences on sedimentation.