This vector contour dataset represents the distribution of the estimated, theoretical potential 'geothermal resources' (in GJ/m2 or PJ/km2) for the Carboniferous Fell Sandstone Formation (Mid Border Group) in the Northumberland-Solway Basin. This grid is the heat-in-place, and represents the amount of heat contained in the productive parts of the identified aquifers (i.e. those with sufficient porosity and permeability to be considered hot sedimentary aquifer resources).