These generalised soil texture groupings are derived by comparing samples of measured soil textures (%clay, %silt and %sand) against a simplified soil grain-size ternary plot based on DEFRA: Cross Compliance Guidance for Soil Management 2006 and shown below. Note that this map uses terms that refer to Light soils (i.e. sand/silt rich), Medium soils (i.e. loams) and Heavy soils (i.e. clay rich). The classifications are based on analyses of archive GBase and geotechnical samples as well as expert judgment (where sample data is not available). Most parent materials generate a broad range of soil texture so these groupings should be regarded as 'indicative'. The 'Mixed or Organic' classification denotes highly variably textured soils or the presence of Peat (for which no texture data available).