1:250 000 Geological Maps (UTM Series)
Maps in this series show three sorts of geological information: solid 'bedrock' geology, (S), Quaternary or 'drift' geology (Q), or sea-bed sediments (Ss).
These are usually presented as separate sheets, although sea-bed sediments and Quaternary geology, or sea-bed sediments and solid geology may be shown on the same sheet.
Other data may also be shown as figures or diagrams.
The UTM (Universal Transverse Mercator projection) series maps cover an area of 1 degree of latitude by 2 degrees of longitude.
Sheets are indexed by their south-west corner co-ordinates.
Quaternary geology maps show information for offshore areas only; onshore areas are not covered unless indicated.