A new edition of the bedrock geology map of the United Kingdom

Abstract

This paper describes how the digital data and published paper map for the new 5th edition 1:625,000 scale bedrock geological map of the United Kingdom were created. The map is published in two sheets, North and South, covering Scotland, Northern Ireland, the Isle of Man, England and Wales. The first edition was created in 1948 by the simplification and reduction of more than 500 individual maps at 1:63,360 scale (one-inch to one-mile) and this remained the basis for revisions up to the 4th edition. In contrast, the digital data for the map face of the 5th edition were created from two main sources: a digital geological map dataset of Great Britain at 1:50,000 scale; and the geological map of Northern Ireland at 1:250,000 scale. The following phases of work are described: a) data analysis and provisional unit selection; b) re-digitising; c) data review and revision; d) cartography and compilation of marginalia. For users of earlier editions the map retains a familiar appearance even though it is completely new. The rocks are grouped together differently and classified in new ways and they are identified with a new alphanumeric system of labels. The content and layout of the marginalia have been redesigned with new explanatory notes and cross sections included. Two explanatory booklets provide succinct summaries of the geological history of each area.The maps accompanying this article are customised digital images created especially for publication, for non-commercial use, in the Journal of Maps