Gephysical exploration of the subsurface geology at the Butterknowle Fault, County Durham

Surface geology does not provide sufficient evidence for the geometry of the Butterknowle Fault and the sub-surface geology that surrounds it. A large gravity anomaly measured across the fault is unexplained by the fault alone. We utilised indirect methods of interpretation and a computer model to propose that south of the Butterknowle Fault, the Carboniferous limestone thickens in the order of several thousands of meters and that this is the most likely cause of the observed gravity anomaly.