Devonian Geography

Abstract

In the previous chapters we have examined some of the major associations of sedimentary rocks that are present in the Devonian system and have attempted to relate their origins to models of modern sedimentary environments and processes. This is a rather crude exercise and refinements are highly desirable. Most of the models of Devonian sedimentary environments must stand or fall not only on the basis of their immediate suitability but also on whether or not they are valid in the context of regional, and ultimately, world Devonian palaeogeography. In many cases we are not certain that the models account for every aspect of a particular sedimentary assemblage. For example, the detailed and convincing interpretation of upwards-fining cycles within the Old Red Sandstone facies has been applied to a very large number of formations, which now on closer inspection reveal details that call for a different model. This is not to deny the usefulness of the original concept but it serves to emphasise that interpretations need to be regarded as temporary, to be changed as improvements in knowledge continue. Since most of what is on the previous pages of this book is culled from the literature it is likely to be already out of date, but that is the fate of works such as this.