March 20091 London’s foundations protecting the geodiversity of the capital The London Plan (Spatial Development Strategy for Greater London) London Plan Implementation Report London’s Foundations protecting the geodiversity of the capital The London Plan (Spatial Development Strategy for Greater London) London Plan Implementation Report March 2009 1 London’s Foundations protecting the geodiversity of the capital The London Plan (Spatial Development Strategy for Greater London) London Plan Implementation Report March 2009 2 Copyright Greater London Authority March 2009 Published by Greater London Authority City Hall The Queen’s Walk London SE1 2AA www.london.gov.uk enquiries: 020 7983 4100 minicom 020 7983 4458 ISBN 978 1 84781 250 6 Photograph credits Cover: East Pages 146, 148, 150, 152: Vernon Marks Pages 157, 164: Bryan Cozens All other photographs: Joanna Brayson This publication is printed on recycled paper Copies of this London Plan Implementation Report are available from www.london.gov.uk. 3 Acknowledgements This project was made possible by funding from Natural England via the Defra Aggregates Levy Sustainability fund (ALSF), The Greater London Authority (GLA), British Geological Survey (BGS) and Natural England London Region. In-kind project support was provided by London Brough of Lambeth, Natural England, Hanson UK, British Geological Survey, Harrow and Hillingdon Geological Society, South London RIGS Group and London Biodiversity Partnership. BGS prepared the draft report on behalf of the London Geodiversity Partnership, led by the GLA. BGS is a component body of the Natural Environment Research Council. BGS Report authors: H F Barron, J Brayson, D T Aldiss, M A Woods and A M Harrison BGS Editor: D J D Lawrence Project Steering Group: Greater London Authority John O’Neil, Jane Carlsen British Geological Survey Hugh Barron, Charlotte Herbert, Keith Ambrose Government Office London Julie Shanahan, Natalie Jagger Natural England Adam Elwell, Jonathan Larwood London Borough of Lambeth Iain Boulton Harrow and Hillingdon Geological Society Sheppy Shepherd South London RIGS Group Vernon Marks London Biodiversity Partnership Mike Waite Hanson UK Malcolm Keeble Queen Mary College, University of London Murray Gray The Mayor would like to acknowledge the work and extend thanks to the London Geodiversity Partnership who contributed to the preparation of this implementation report and to those who responded to the consultation on the draft. Maps and diagrams have been prepared by the authors, except where stated. This report includes mapping data licensed from Ordnance Survey with permission of the Controller of Her Majesty's Stationery Office © Crown Copyright and/or database right 2008. All rights reserved. BGS Licence number 100037272/2008. 4 5 Contents Mayor’s foreword 8 Summary 10 1 Introduction 12 Aims 12 2 Understanding geodiversity 14 What is it and why is it important? 14 Relationship with biodiversity 16 Geodiversity and spatial planning 17 3 Geological conservation 20 Statutory designations 20 Non-statutory designations 22 4 London’s geological heritage 24 Evolution 24 Bedrock geology 31 Quartenary deposits 46 Fossils and palaeontology 55 5 Geological resources and built heritage 59 Mineral resources 59 Water resources 62 6 Evaluating London’s geodiversity 64 Review of geodiversity guidance and assessment criteria 64 Geodiversity auditing 66 Project GIS 67 7 Geodiversity audit results and recommendations 69 Criteria for selection of RIGS and LIGS 69 Audited SSSIs 69 Recommended RIGS 69 Potential LIGS 71 8 Geodiversity guidance to boroughs 73 Policy 73 Geodiversity and the wider landscape 73 Implementation 75 9 Geodiversity Action Planning 77 Appendices 1 Sites selected for geodiversity auditing 78 2 Site selection criteria 82 3 Field audit recording sheet 85 4 GIS datasets used in geodiversity audit 87 5 Site assessment sheets 88 6 Summary of geological strata of sites 163 Glossary 164 References and resources 169 6 7 Mayor’s foreword Our city’s development is intimately bound to its geodiversity – to the variety of natural materials and processes that have shaped it over the millenia and continue to do so. It was London’s bountiful supply of gravel and brick clay that helped transform it from a tiny hamlet in to our capital city. It was the relative ease with which the Victorians could excavate London's soil that enabled them to construct the extensive underground tunnel network that we still rely on today. When we piece together the geological jigsaw puzzle we gain insights in to our past. But crucially this also helps us to understand our present and future. We need this knowledge to safeguard our environment, our heritage, and our wildlife, but also in order to most effectively harness our resources and develop our city’s economy and infrastructure in a sustainable way. London’s Foundations will help us to protect and value geodiversity. It identifies and records features of geological value and provides a foundation for developing a Greater London Geodiversity Action Plan that will go even further towards ensuring geological conservation in the decades to come. Boris Johnson Mayor of London 8 9 Summary This report describes a geodiversity audit of London commissioned by a partnership led by the Greater London Authority (GLA), which includes the British Geological Survey (BGS), Natural England, Government Office for London, London Biodiversity Partnership, London Borough of Lambeth, Harrow and Hillingdon Geological Society, South London London RIGS Groups, Hanson UK and Queen Mary College, University of London. The project was funded by an Aggregates Levy Sustainability Fund grant from Natural England plus additional support from the GLA, BGS and Natural England London Region. The audit began with a review of the available geodiversity documentation for London including: BGS field maps, databases and publications; Regional Important Geological Sites (RIGS) Group information; Natural England Sites of Special Scientific Interest (SSSI) and Geological Conservation Review (GCR) documentation; and documentation and data from the GLA and London Boroughs. An initial list of around 470 sites with potential for geodiversity value was compiled from this information. This list was then narrowed down to 100 for further assessment by exporting site locations to a GIS and cross-checking against digital aerial photography backed up by BGS staff local geological expertise. Using the procedure set out in this report field auditing was carried out by BGS staff and the South London RIGS Group between November 2007 and April 2008. From the list of 100 sites, 35 sites were found to be suitable for detailed auditing. Harrow and Hillingdon Geological Society audited a further site in November 2008, bringing the total to 36 sites. Using the criteria set out in this report 14 of the 36 sites are recommended for designation as Regionally Important Geological/geomorphological Sites (RIGS) in borough Local Development Documents. Of the 33 London boroughs, RIGS are recommended in eight, with five in Bromley, three in Croydon and one each in Lewisham, Ealing, Greenwich, Harrow, Hillingdon and Bexley. Using the criteria set out in this report 15 of the 36 sites have the potential to be designated as Locally Important Geological Sites (LIGS). These sites are located in nine boroughs, three in Waltham Forest, two in Bromley, two in Islington and one each in Barnet, Lewisham, Redbridge, Wandsworth, Southwark and Sutton. Planning proposals should have regard to geodiversity in order to implement strategic and local policies. Sites should be protected, managed and enhanced and, where appropriate, new development should provide improvements to the geodiversity value of a site. This can include measures that promote public access, study, interpretation and appreciation of geodiversity. In addition to individual sites of geodiversity interest, Greater London has distinctive natural landscapes shaped by geological processes, such as undulating chalk downlands with dry valleys in south London, and river terraces forming long flat areas separated by steeper areas of terrace front slopes. This natural topographic geodiversity underlying London should be understood, respected and only altered in that knowledge with full knowledge of it origin and form. Planners are encouraged to use authentic contouring in restoration work and new landscaping schemes, maintain the contributions of natural topography, rock outcrops, landscape features, and to maintain soil quality, quantity and function. 10 11 1 Introduction 1.1 The London Plan (Consolidated with Alterations since 2004) published in February 2008, hereafter referred to as the London Plan, aims to protect and promote geodiversity in London, stating that the Mayor will work with partners to identify Regionally Important Geological/ geomorphological Sites (RIGS) that should be protected. These sites, along with the designated national sites, would be of strategic importance for geodiversity across London. This report identifies suitable RIGS and provides guidance to enable the boroughs to identify Locally Important Geological Sites (LIGS), which would represent additional sites of local value. 1.2 This Implementation Report provides advice that shows how the London Plan policy can be achieved. It is intended for all those interested in the geodiversity of the Greater London area and seeks to address geodiversity in its very broadest sense. Although dealing with a varied, and sometimes complex, range