The Great Oolite Group (Bathonian, Middle Jurassic) of the mid Cotswold Hills is a classic example of a limestone-dominated succession deposited on a carbonate ramp, with a range of distinct carbonate and subordinate siliciclastic facies belts which migrated basinward through time. The outcrops have been mapped by the British Geological Survey (BGS) and a number of fully cored boreholes logged in detail. Subsequently, its architecture has been modelled in 3D using the geological modelling software GSI3D (www.gsi3d.org.uk) as cross sections, surfaces and volumes across an area of about 1500 square kilometres which extends up to nine kilometres south-east in the subcrop