Photographic negatives of Geological map 'Standards', manuscript and published maps produced by the Survey on County Series (1:10560) and National Grid (1:10560 & 1:10000) Ordnance Survey base maps. Current holdings over 41,000 maps for Great Britain. The majority of maps were scanned in 2004, any new maps produced are scanned and added to the collection. This is essentially a back up collection for disaster recovery.