of Early Jurassic age whilst those to the east are of Middle Jurassic origin; Inferior Oolite Group (Middle Redbourne Group)(Middle Jurassic epoch) Lincolnshire Limestone Formation (Lincolnshire Limestone) Grantham Formation (Lower Estuarine Beds) / Northampton Sand Formation Lias Group (Lower Jurassic epoch) Whitby Mudstone Formation (Upper Lias or Coleby Mudstones) Marlstone Rock Formation (Marlstone Rock Bed) Charmouth Mudstone Formation (Middle Lias or Coleby Mudstones) Parts of this sequence of rocks have gone by different names in the past indicated above by italicised names in brackets, and these continue to be found in older geological literature and maps. The Charmouth Mudstones form the lower ground to the west and the lowest part of the "cliff" whilst the Lincolnshire Limestone forms the plateau surface to the east of the scarp. The two gaps in the ridge at Lincoln and at Ancaster are interpreted as indicating the former course of the eastward flowing proto-Trent. The river flowed from the Nottingham area towards the North Sea via the Vale of Belvoir and the gap in the ridge at Ancaster. At a later stage it used the Lincoln Gap before assuming its present northerly course to join with the Yorkshire Ouse to form the Humber. List of cliff villages From north to south the "towns, villages and city (Lincoln)" are as follows along the cliff: Winteringham, on the bank of the Humber Winterton Roxby Burton upon Stather Scunthorpe (Town) Kirton in Lindsey (Town) Grayingham Blyborough Willoughton Hemswell Harpswell Glentworth Fillingham Ingham Cammeringham Brattleby Aisthorpe Welton Cliff Welton Scampton North Carlton South Carlton Burton by Lincoln Lincoln – break in the Edge (River Witham) (City) Canwick Bracebridge Heath Waddington Harmston Coleby Boothby Graffoe Navenby Wellingore Welbourn Leadenham Fulbeck Caythorpe Normanton Carlton Scroop Ancaster – break in the Edge (River Slea) Honington Barkston Syston Belton Londonthorpe Manthorpe Grantham (Town) References External links Escarpments of England Ridges of England Landforms of Lincolnshire