The Bedrock summary lithologies dataset is digital geological map across the bulk of the UK Continental Shelf (UKCS), for areas up to a water depth of 200m, which groups the bedrock lithologies (rock types) into classes based on similar engineering geology characteristics. The map is derived from the 1:250,000 scale digital bedrock map of the UKCS, called DiGRock250k, which is available separately from the BGS. The map was produced in 2014 in collaboration with, and co-funded by, The Crown Estate as part of a wider commissioned project to assess seabed geological constraints on engineering infrastructure across the UKCS. The divisions on the map combine the bedrock formations into 8 classes (with several subdivisions) of similar strength and lithological variability, each with a ‘Category’ title that summarises their main lithological character: Class1 – Igneous; Class 2 - Tertiary Sandstone and Limestone; Class 2.5 - Tertiary Sandstone and Limestone Interbedded; Class 3 - Tertiary Mudstone; Class 4 - Mesozoic Sandstone and Limestone; Class 4.5 - Mesozoic Sandstone and Limestone Interbedded; Class 5 - Mesozoic Mudstone; Class 6 – Chalk; Class 7 – Metamorphic; Class 8 - Palaeozoic Sedimentary. The data are held by the BGS as an ESRI ArcGIS Shapefile.