Tunstead Quarry (p. 17) lies in a zone of general east–west faulting. Several dip-slip faults of this trend intersect the 1.5 km-long quarry face, and one of these [SK 097 739] has been observed by Mr P. F. Dagger (personal communication) to have reversed both its throw and the dip direction of the fault plane, as the face has moved back over a number of years.