“…An outline of the lithology and distribution of much of the Permian marine sequence at outcrop in north-east England was given by Sedgwick (1829) and details have been added by the authors of Geological Survey Memoirs and many other workers (see individual site accounts for full references); more recent syntheses are by the writer (Smith, 1970a(Smith, , 1974a(Smith, , b, 1980a(Smith, , b, 1992, Pettigrew (1980), Kaldi (1980Kaldi ( , 1986a, Harwood (1981Harwood ( , 1989, Aplin (1985), Goodall (1987) and Hollingworth (1987). Data from outcrop and boreholes are now sufficient for a lateral succession of facies belts to be recognized in three of the main carbonate rock units and for palaeogeographical maps of these to be attempted [see Kaldi (1980Kaldi ( , 1986a and Harwood (1981Harwood ( , 1989 for parts of the sequence in the Yorkshire Province and Smith (1989) for the full sequence in the Durham and Yorkshire provinces].…”