Lee, J.R., Phillips, E., Booth, S.J., Rose, J., Jordan, H.M., Pawley, S.M., Warren, M., Lawley, R.S. 2013. A polyphase glacitectonic model for ice-marginal retreat and terminal moraine development: the Middle Pleistocene British Ice Sheet, northern Norfolk, UK. Proceedings of the Geologists’ Association, 124, 753-777. PRE-PROOF ACCEPTEF MANUSCRIPT. A polyphase glacitectonic model for ice-marginal retreat and terminal moraine development: the Middle Pleistocene British Ice Sheet, northern Norfolk, UK Jonathan R. Lee1,2*, Emrys Phillips3, Stephen J. Booth1,2, James Rose2,1, Hannah M. Jordan1, Steven M. Pawley2, Martin Warren4, Russell S. Lawley1 1British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK. 2Department of Geography, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK. 3British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA, UK. 4The Northfolk Project, Chesterfield Lodge, West Street, Cromer, Norfolk, NR27 9DT, UK. *Corresponding Author:
[email protected] Keywords: glacitectonic; terminal moraine; active retreat; Cromer Ridge; thin-skinned; East Anglia Abstract Recent investigations from modern environments demonstrate that many terminal moraines do not simply record a single glacial maximum, but instead reveal a complex pattern of ice-marginal behaviour including polyphase retreat. Within this study, we examine the geomorphology, geology and internal structure of a terminal moraine complex – the ‘Cromer Ridge’ in north Norfolk to reconstruct patterns of ice-marginal behaviour. Previously, this landform was interpreted as the limit of a southern extension of the British Ice Sheet during a Middle Pleistocene glaciation. Evidence presented here reveals a more complicated pattern of ice-marginal behaviour with the ‘Cromer Ridge’ reinterpreted as a ‘complex’ comprising several ridge elements.