It has been suggested by model studies that swell formation may occur in a mobile layer subjected to faulting where the fault throw is less than the mobile layer thickness. In such a case in the real earth, differential overburden loading due to deposition or erosion at a later stage will cause a mobile layer (e.g. salt rock) to flow from the region of higher to the region of lower load stress via the fault zone, resulting in swell formation on the upthrow side of the fault. Two different examples of this effect are illustrated in marine seismic sections from the North Sea. Associated with one of these examples are seismic events which appear to indicate mass movement of sediment down the fault scarp prior to the deposition of the main body of Zechstein halite at this location.