Map based index (GeoIndex) 1:50000 series paper geological map availability

This layer of the map based index (GeoIndex) shows the availability of 1:50000 series paper geological maps. For England and Wales (and Northern Ireland), map sheets normally cover an area 30 km east-west and 20 km north-south; in Scotland the coverage is 20 km east-west and 30 km north-south. The 1:50 000 geological map grids are based on an early Ordnance Survey 1:63 360 (one inch to one mile) scale map grid and are not related to the current Ordnance Survey 1:50 000 map sheets. Maps are normally available in both flat and folded formats.