In 2011 the British Geological Survey (BGS) decided to begin the assembly of a National Geological Model (NGM) from its existing and on-going geological framework models , comprising integrated national crustal, bedrock and Quaternary models. The bedrock component is the most advanced of these themes and comprises both the calculated models and a complementary network of cross-sections that provide a fence diagram for the bedrock geology of Great Britain. This fence diagram, the GB3D_v2012 dataset is available in a variety of formats from the BGS website www.bgs.ac.uk as free downloads. It complements the existing 1:625 000 scale mapsheets published by BGS utilising the same colour schema and geological classification. The 121 component cross-sections extend to depths between 1.5 and 6 km; they have an aggregate length of over 20,000 km, and they are snapped together at their intersections to ensure total consistency. The sections are based on the existing BGS geological framework models where they cut through them, they also take account of the vast wealth of published data on the subsurface structure of Britain both from BGS and in the literature. Much of this is in the form of cross-sections, contour maps of surfaces, and thicknesses (isopachs). The fence diagram has been built in the Geological Surveying and Investigation in 3D (GSI3D) software. It is envisaged that this dataset will form a useful educational resource for geoscience students and the general public, and also provide the bedrock geology context and structure for regional and catchment scale studies. The fence diagram was built in 2009-12 using funding from the BGS National Capability Programme and the Environment Agency of England and Wales. 14 expert regional geologists compiled the sections.
