A Geological Assessment of the Landslides in the Ironbridge Gorge, Shropshire
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A geological assessment of the landslides in the Ironbridge Gorge, Shropshire Prepared for Wardell Armstrong LLP by the British Geological Survey Commissioned Report CR/08/157N BRITISH GEOLOGICAL SURVEY LAND USE AND DEVELOPMENT COMMISSIONED REPORT CR/08/157N A geological assessment of the landslides in the Ironbridge Gorge, Shropshire C. V. L. Pennington Contributor/editor The National Grid and other Ordnance Survey data are used Professor M. G. Culshaw and Dr A. H. Cooper with the permission of the Controller of Her Majesty’s Stationery Office. Licence No: 100037272. Keywords Landslides; Ironbridge. Bibliographical reference PENNINGTON, C. V. L.. 2008. A geological assessment of the landslides in the Ironbridge Gorge, Shropshire. British Geological Survey Commissioned Report, CR/08/157. 40pp. Copyright in materials derived from the British Geological Survey’s work is owned by the Natural Environment Research Council (NERC) and/or the authority that commissioned the work. You may not copy or adapt this publication without first obtaining permission. Contact the BGS Intellectual Property Rights Section, British Geological Survey, Keyworth, e-mail [email protected]. You may quote extracts of a reasonable length without prior permission, provided a full acknowledgement is given of the source of the extract. Maps and diagrams in this book use topography based on Ordnance Survey mapping. 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This report presents factual information about the landslides of the Ironbridge Gorge area based on a limited desk study and no fieldwork took place. Many of the reports that it references are more than 30 years old and it must be stressed that this current work and the previous references should not be used to make any decisions about land use or engineering without making a proper assessment of the ground. The unstable nature of the landslide areas mean that the situation on the ground can change considerably over short periods of time. Acknowledgements The author would like to thank Professor Martin Culshaw, Dr Anthony Cooper, Dr Claire Foster and Dr Andrew Gibson who have freely given advice, provided local knowledge and helped to review this report. Contents Executive Summary ....................................................................................................................... i Acknowledgements ......................................................................................................................... i Contents ........................................................................................................................................... i 1 Introduction .............................................................................................................................. 1 1.1 Terms of Reference ........................................................................................................ 1 1.2 Methodology ................................................................................................................... 1 1.3 Location, History and Topography ................................................................................. 1 2 Geological Summary ................................................................................................................ 3 2.1 Bedrock Geology ............................................................................................................ 3 2.1.1 Silurian ................................................................................................................ 3 2.1.2 Carboniferous ...................................................................................................... 6 2.2 Superficial Geology ........................................................................................................ 7 2.3 Artificial Deposits ........................................................................................................... 7 2.4 Structure ........................................................................................................................ 10 3 Landslides ................................................................................................................................ 12 3.1 National Landslide Database ........................................................................................ 12 i CR/08/157 3.1.1 Jackfield Landslide ........................................................................................... 13 3.1.1.1 Sweyney Cliff and South Ironbridge ....................................................... 19 3.1.2 Ironbridge School .............................................................................................. 19 3.1.3 Lloyd's Coppice ................................................................................................ 20 3.1.3.1 New Buildings ......................................................................................... 23 3.1.4 Jockey Bank ...................................................................................................... 23 3.1.5 The Lees and Lee Dingle .................................................................................. 24 3.1.6 Coalport............................................................................................................. 25 3.1.7 Sutton Wood 1 .................................................................................................. 25 3.1.8 Ladywood ......................................................................................................... 25 3.1.9 The Coalbrookdale Landslides ......................................................................... 25 3.1.9.1 Cherry Tree Hill ...................................................................................... 26 3.1.9.2 Rough Park Way...................................................................................... 27 3.1.9.3 Darby Road .............................................................................................. 27 3.1.9.4 Jiggers Bank ............................................................................................ 27 3.1.10 The Birches, Buildwas Bridge and Holbrook Coppice ..................................... 28 3.1.11 Coalport Road ................................................................................................... 30 3.1.12 Hay Farm .......................................................................................................... 30 4 Discussion ................................................................................................................................ 31 5 Conclusions ............................................................................................................................. 31 6 References ............................................................................................................................... 32 Appendix 1 ................................................................................................................................... 33 FIGURES Figure 1 Location map of study area in the Ironbridge Gorge, Shropshire .................................... 2 Figure 2 Topographic relief model of Ironbridge Gorge taken from NextMap™ .......................... 2 Figure 3 Extract from