Offshore Quaternary 250K

This dataset shows the distribution of previously interpreted Quaternary lithostratigraphic units within the shallow subsurface of the UK continental shelf. This dataset comprises a compilation of legacy BGS 1:250k Quaternary Geology map sheets, provided here in digital form for the first time. This is a GIS dataset composed of vector polygons, each representing an area where a particular formation has been mapped. Large areas of the UK offshore are covered, at a scale of 1:250 000.

The legacy 1: 250k map sheet interpretations (e.g. Spurn, Anglesey) have not been modified, and are presented in their original form, mosaiced together as a single digital product. As a result, there are known boundary mismatches between the previous map sheet areas that remain in the dataset. The map compilation is not informed by new data or analyses and no attempt was made to smooth or ‘correct’ the boundary issues. This was to avoid offering a false sense of accuracy that is not based on updated systematic analysis. Please see the User Guide for further information. 

Additional information from the original map sheets has been included in the attribute fields, including a lithological description for each formation. The BGS lexicon code for each formation has been supplied, so users can research any formation of interest. The maximum and minimum age of each formation, in a variety of formats, has also been added. This key lithostratigraphic information was sourced from Stoker et al. (2011). While work to refine Quaternary stratigraphic frameworks is ongoing, the principal drive behind this release is to make original 1:250k map data available in a digital format.