BGS Geology 10k - 25k (DiGMapGB-10 & DiGMapGB-25) version 3

The BGS GeologyGB10-25 datasets are a digital representation of the geological maps of Great Britain at 1:10 000 and 1:25 000 scale. This is the base scale at which BGS surveys, and the dataset covers up to 52% of Great Britain published at 1: 10 000 and 1:25 000 scale. The content is derived from the surveyed and published maps together with additional new survey at those scales. BGS Geology10-25 V3.25 dataset includes 4 geological themes and 1 map component (4 polygon and 1 linear), providing information on the geology Great Britain. Artificial (man-made) theme (shown as polygons) indicates areas where the ground surface has been significantly modified by human activity. Whilst artificial ground may not be considered as part of the 'real geology' of bedrock and superficial deposits it does affect them. Artificial ground impacts on the near surface ground conditions which are important to human activities and economic development. Due to the constantly changing nature of land use and re-use/redevelopment, caution must be exercised when using this data as it represents a snapshot in time rather than an evolving picture hence the data may become dated very rapidly. Bedrock geology describes the main mass of solid rocks forming the earth's crust. Bedrock is present everywhere, whether exposed at surface in outcrops or concealed beneath superficial deposits or water bodies. Geological names are based on the lithostratigraphic or lithodemic hierarchy. The lithostratigraphic scheme arranges rock bodies into units based on rock-type and geological time of formation. Where rock-types do not fit into the lithostratigraphic scheme, for example intrusive, deformed rocks subjected to heat and pressure resulting in new or changed rock types; then their classification is based on their rock type or lithological composition. This assesses visible features such as texture, structure, mineralogy. Mass movement describes areas where deposits have moved down slope under gravity to form landslips. These landslips can affect bedrock, superficial or artificial ground. Mass movement deposits are described in the BGS Rock Classification Scheme Volume 4. However, the data also includes foundered strata, where ground has collapsed due to subsidence (this is not described in the Rock Classification Scheme). Caution should be exercised with this data; whilst mass movement events are recorded in this layer, due to the dynamic nature of occurrence significant changes may have occurred since the data was released, as such it should be viewed as a snapshot in time (data should be regarded as at 2008). Linear: Linear features are associated most closely with the bedrock theme either as an intrinsic part of it for example marine bands or affecting it in the case of faults. However, landform elements are associated with both bedrock and superficial deposits. The linear features are organised into seven main categories i.e., Alteration Area”, “Bedrock”, “Faults”, “Fold Axis”, “Fossil Horizon”, “Landform”, and “Mineral Vein”, some having applicable attribution i.e., a LEX-RCS code or a fault name entered. Superficial: Superficial deposits are the youngest geological deposits formed during the Quaternary. They lie on top of older deposits or rocks referred to as bedrock. Superficial deposits were laid down by various natural processes and as such, the deposits are denoted by their BGS lexicon name, which classifies them based on mode of origin (lithogenesis) i.e., 'glacial deposits', 'river terrace deposits' or based on their composition i.e., 'peat'. Most are unconsolidated sediments. All five data themes are available in vector format (containing the geometry of each feature linked to a database record describing their attributes) as ESRI shapefiles and are available under BGS data licence.

Tags: Anthropogenic factor, Bed rock, GIS, Geological data, Geological maps, Geology, Landslides, NERC_DDC, Surficial geology
Organization: British Geological Survey (BGS)