Specialist maps of the channel islands prepared by German military geologists during the Second World War: German expertise deployed on British terrain

During the German occupation of the Channel Islands, military geologists produced specialist maps to support their development as part of the Atlantic Wall: the line of fortifications marking the western boundary of German-occupied Europe. For Jersey, maps showed features of groundwater and quarry sites for building materials, primarily at a scale of 1 : 25 000. For Guernsey, maps at this scale were prepared to depict bedrock and superficial geology, and also maps which showed sites for building materials, water supply and features of military geology. For Alderney, maps at 1 : 10 000 showed bedrock geology, water supply, building materials plus tunnelling conditions, and military geology. Only after, contemporary copies of these maps were produced, hand-drain upon printed topographical base-maps. Some are now presented in Germany at the Bundesarchiv-Militarachiv others in the USA at the National Archives and Records Administration. They include the only military geology maps, the earliest large-scale groundwater maps and arguably the earliest large-scale building resources maps, for any part of the British Isles.