Lower Greensand/Bowland Shale Formation and Craven Group separation map

Area where aquifer and shale/clay are present	Central Lincolnshire Note that, for the purposes of drafting this separation map, the maximum depth of the Lower Greensand aquifer is taken to be 400 mbgl based on the recommendations in the UK TAG report. More information about this can be found in the methods section
Thickness of intervening strata	About 2000 to 2750 m.
Lithology of intervening strata	Mixed permeability Millstone Grit Group and Pennine Coal Measures Group (mudstones, siltstones and sandstones) Permeable Magnesian limestone (principal aquifer) Permeable Triassic sandstone (principal aquifer) Low permeability Mercia Mudstone Group Low permeability Lias Group (clay) Permeable Great Oolite Group and Inferior Oolite Group (principal aquifer) Low permeability Kellaways Formation, Oxford Clay Formation and Osgodby Formation (clay) Low permeability Kimmeridge Clay Formation and Ampthill Clay Formation (clay) Permeable Spilsby Sandstone Formation (principal aquifer) Permeable Lower Cretaceous sandstone Low permeability Wealden Group deposits
Other major aquifers in the area	Chalk (above) Carboniferous limestone (below)
Other shales or clays in the area	None
Aquifer map	Lower Greensand principal aquifer
Shale/clay map	Bowland Shale Formation and Craven Group shale/clay unit

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