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_v2014 dataset is available in a variety of formats from the BGS website www.bgs.ac.uk as free downloads, it supercedes the earlier 2012 version. The model complements the existing 1:625 000 scale mapsheets published by BGS utilising the same colour schema and geological classification. The component cross-sections extend to depths between 1.5 and 6 km; they have an aggregate length of over 25,000 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 together and incorporate around 300 deep stratigraphic boreholes across England and Wales. The sections also take account of the vast wealth of published data on the subsurface structure of Britain both from BGS and in the scientific 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 has been built in stages between 2009-14 using funding from the BGS National Capability Programme the Environment Agency of England and Wales, and the Nuclear Decommissioning Authority. Some 16 expert regional geologists compiled the sections.
