The BGS database of geological maps is an index into BGS holdings of modern and historical published geological maps, geological standards and field slips, and also contains a range of other map series, including geophysical maps, geochemical maps, hydrogeological maps, thematic maps and other small-scale miscellaneous non-series maps. Historical vertical and horizontal sections, as well as indices to colours, are also included. The database comprises map metadata, including the title, theme, survey and revision years, publication years, mapped geological theme, base material, map function, colouration, approval status and the spatial extent of each map sheet. An accompanying file store contains high-resolution JPEG2000 scans for delivery, as well as various digital master and delivery formats. For a small number of maps, no scan exists. In total, the database contains over 240,000 scans of over 130,000 maps and field slips. The majority of the maps in the database cover Great Britain, but other regions are also represented, including a historical series of 1-inch maps of Ireland, 6-inch maps of the Isle of Man, 1:25 000 scale maps of the Channel Islands, and various overseas maps. The database contains a record of all geological maps produced by the British Geological Survey and its predecessors since the commencement of systematic geological mapping in the 1830s. The BGS Maps Database is mostly an archive of previous BGS maps, and is not the same as the latest BGS digital mapping. The maps within the database may differ significantly from BGS digital vector mapping. Further information about BGS digital vector mapping is available on the BGS website, under 'BGS Datasets'. The database has evolved over time, originally being a series of discrete databases. These databases have now been aggregated into a single dataset. BGS published maps, as well as 1:10 560 and 1:10 000 large-scale geological maps of England and Wales, and Scotland, are available through the BGS Maps Portal. Field slips and some thematic maps are not included on the BGS Maps Portal. The information about a map is normally a transcription from the map itself. Sometimes key information such as the title may not be actually printed on the map. Where this is the case the information is supplied in square brackets, e.g. [Kirk Maiden]. Information in square brackets means the information is supplied by the cataloguer and is not transcribed from the item.
The BGS Maps Portal provides access to over 45 000 high-resolution viewing images of almost all the small, medium and large scale maps produced by the BGS since mapping started in 1832 right up to the most recent maps released in 2020. It incorporates all the earlier maps and history pages that were previously made available through the BGS ‘Historical maps of the Geological Survey of Great Britain and Ireland’ web resource.