Geology of the Salisbury Sheet Area Report on the Geology of Sheet 298 Salisbury and its adjacent area. A compilation of the results of the survey in Spring and Autumn 2003 and from the River Bourne survey of 1999 Internal Report IR/06/011 i ii Natural Environment Research Council British Geological Survey Onshore Geology Series Geology of the Salisbury Sheet Area Report on the Geology of Sheet 298 Salisbury and its adjacent area. A compilation of the results of the survey in Spring and Autumn 2003 and from the River Bourne survey of 1999 Internal Report IR/06/011 P M Hopson, A R Farrant, A J Newell, R J Marks, K A Booth, L B Bateson, M A Woods, I P Wilkinson, J Brayson and D J Evans Geographical index UK, S England, Wiltshire, Hampshire, Salisbury, River Avon, River Wylie, River Nadder, River Bourne, River Ebble Subject index Geology, Quaternary, Palaeogene, Cretaceous, Jurassic, Chalk and concealed geology Bibliographic reference P M Hopson, A R Farrant, A J Newell, R J Marks, K A Booth, L B Bateson, M A Woods, I P Wilkinson, J Brayson and D J Evans. Geology of the Salisbury Sheet Area. British Geological Survey Internal Report IR/06/011 © NERC copyright 2006 Keyworth, Nottingham, British Geological Survey 2006 iii BRITISH GEOLOGICAL SURVEY The full range of Survey publications is available through the Sales Desks at Keyworth Parent Body and at Murchison House, Edinburgh, and in the BGS London Information Office in the Natural Natural Environment Research Council History Museum Earth Galleries. The adjacent Polaris House, North Star Avenue, Swindon, bookshop stocks the more popular books for Wiltshire SN2 1EU. sale over the counter. Most BGS books and Telephone 01793 411500 reports are listed in HMSO's Sectional List 45, Telex 444293 ENVRE G and can be bought from HMSO and through Fax 01793 411501 HMSO agents and retailers. Maps are listed in the BGS Map Catalogue, and can be bought from Ordnance Survey agents as well as from Kingsley Dunham Centre BGS. Keyworth, Nottingham NG12 5GG. 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Telephone 0171 938 9056/57 Fax 0171 584 8270 Forde House, Park Five Business Centre, Front Cover: Stonehenge 2004, a view looking Harrier Way, Sowton, Exeter, EX2 7HU. northeast from [SU 122 421]. Photo P 535208. Telephone 01392 78312 Fax 01392 437505 Geological Survey of Northern Ireland, 20 College Gardens, Belfast BT9 6BS. Telephone 01232 666595 Fax 01232 662835 Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB. Telephone 01491 838800 Telex 849365 HYDROL G Fax 01491 692345 iv v Geology of the Salisbury Sheet Area Draft Frontispiece. Stonehenge, Amesbury 1926 photographed by J Rhodes. Looking east-northeast. General view from ditch. [SU 121 421]. Photo P203203. vi Geology of the Salisbury Sheet Area Draft CONTENTS 1 INTRODUCTION 1.1 TOPOGRAPHIC SETTING..................................................................................................................... 1.2 HISTORY OF RESEARCH .................................................................................................................... 1.3 GEOLOGICAL SEQUENCE ................................................................................................................... 2 STRUCTURE 2.1 GENERAL HISTORY ........................................................................................................................... 2.2 FAULTING.......................................................................................................................................... 3 CONCEALED STRATA 3.1 INTRODUCTION.................................................................................................................................. 3.2 CAMBRIAN ........................................................................................................................................ 3.3 ORDOVICIAN TO SILURIAN ................................................................................................................ 3.4 DEVONIAN......................................................................................................................................... 3.5 CARBONIFEROUS............................................................................................................................... 3.6 PERMIAN – TRIASSIC......................................................................................................................... 3.7 LIAS GROUP ...................................................................................................................................... 3.8 INFERIOR OOLITE GROUP .................................................................................................................. 3.9 GREAT OOLITE GROUP...................................................................................................................... 3.10 KELLAWAYS FORMATION ............................................................................................................... 3.11 OXFORD CLAY FORMATION ............................................................................................................ 3.12 CORALLIAN GROUP......................................................................................................................... 4 UPPER JURASSIC 4.1 KIMMERIDGE CLAY FORMATION....................................................................................................... 4.2 PORTLAND GROUP ............................................................................................................................ 4.3 PURBECK GROUP............................................................................................................................... 5 LOWER CRETACEOUS 5.1 WEALDEN ......................................................................................................................................... 5.2 LOWER GREENSAND GROUP ............................................................................................................. 5.3 GAULT FORMATION .......................................................................................................................... 5.4 UPPER GREENSAND FORMATION....................................................................................................... 6 UPPER CRETACEOUS 6.1 GREY CHALK SUBGROUP .................................................................................................................. 6.1.1 WEST MELBURY MARLY CHALK FORMATION ............................................................................... 6.1.2 ZIG ZAG CHALK FORMATION ......................................................................................................... 6.2 WHITE CHALK SUBGROUP ................................................................................................................ 6.2.1 HOLYWELL NODULAR CHALK FORMATION ................................................................................... 6.2.2 NEW PIT CHALK FORMATION......................................................................................................... 6.2.3 LEWES NODULAR CHALK FORMATION........................................................................................... 6.2.4 SEAFORD CHALK FORMATION........................................................................................................ 6.2.5 NEWHAVEN CHALK FORMATION.................................................................................................... 6.2.6 CULVER CHALK FORMATION ......................................................................................................... 6.2.7 PORTSDOWN CHALK FORMATION .................................................................................................. 7 PALAEOGENE 7.1 READING FORMATION ....................................................................................................................... 7.2 LONDON CLAY FORMATION.............................................................................................................. 7.3 WITTERING FORMATION................................................................................................................ 8 QUATERNARY 8.1 PEAT ................................................................................................................................................. 8.2 ALLUVIUM ........................................................................................................................................ 8.3 RIVER TERRACE DEPOSITS................................................................................................................ 8.4 BRICKEARTH ....................................................................................................................................