Geological Conservation Strategy for Hertfordshire
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A Geological Conservation Strategy for Hertfordshire Hertfordshire RIGS Group 2003 Great Britain is the cradle of the science of geology. It was here that many of the periods of geological time were first defined and named. Countless eminent geologists, professional and amateur, have sharpened their eyes and scientific minds on Britain’s earth science sites. Yet these sites, which display the visible evidence of the Earth’s formation and transformation through rocks, fossils and landforms, have been disappearing at an accelerating rate in the face of the many pressures imposed by our modern way of life. Extract from the foreword by David Attenborough to Earth Science Conservation in Britain – A Strategy (Nature Conservancy Council, 1990) Cover photograph A typical scene on the Chalk scarp. Deadman’s Hill, Sandon (photo by Brian Sawford). 2 A GEOLOGICAL CONSERVATION STRATEGY FOR HERTFORDSHIRE 2003 CONTENTS PREFACE...................................................................................................................................................................5 1. INTRODUCTION................................................................................................................................................7 1.1 Geological Site Conservation in Britain ......................................................................................................7 1.2 Geological Site Conservation in Hertfordshire ..........................................................................................8 1.3 The Purposes of this Document .....................................................................................................................9 2. HERTFORDSHIRE'S GEOLOGY - AN OUTLINE.......................................................................................11 3. HERTFORDSHIRE'S GEOLOGICAL RESOURCES ..................................................................................16 3.1 The Hard Rock ................................................................................................................................................16 3.2 Physical Landscape and Geomorphology....................................................................................................16 3.3 Soils...................................................................................................................................................................17 3.4 Water ................................................................................................................................................................18 3.5 Pits and Quarries ...........................................................................................................................................18 3.6 Road/Rail Cuttings.........................................................................................................................................19 3.7 Temporary Exposure Sites ............................................................................................................................19 3.8 Archaeology.....................................................................................................................................................20 3.9 Earth Science Collections of Material from Hertfordshire....................................................................21 3.10 Urban Geology: Building Stones etc .........................................................................................................21 4. THREATS AFFECTING THE GEOLOGICAL RESOURCES ...................................................................22 4.1 Modifications to Landscape ...........................................................................................................................22 4.2 Degradation of Soils .......................................................................................................................................22 4.3 Depletion of the Chalk Aquifer, the Source Rock of our Water............................................................23 4.4 Destruction of Exposures Through the Restoration of Mineral Sites ..................................................23 4.5 Loss of Geological Sites in Road/Rail Cuttings........................................................................................24 4.6 Temporary Exposures in Service Pipeline Trenches...............................................................................24 4.7 Archaeological Sites ......................................................................................................................................24 4.8 The Deterioration of Geology Collections in Hertfordshire Museums ................................................24 4.9 Modernisation of Old Buildings...................................................................................................................25 5. SITE SELECTION.............................................................................................................................................25 5.1 Integrity Sites..................................................................................................................................................25 5.2 Exposure Sites .................................................................................................................................................26 5.3 Selection Criteria...........................................................................................................................................26 6. HERTFORDSHIRE RIGS ................................................................................................................................28 7. STRATEGY OBJECTIVES-MISSION STATEMENT................................................................................31 8. ACTION PLANS ...............................................................................................................................................32 9. REFERENCES ....................................................................................................................................................32 APPENDIX I: SOME RELEVANT INTERNATIONAL AND NATIONAL GEOLOGICAL CONSERVATION INITIATIVES ........................................................................................................................39 1. The Malvern International Task Force for Earth Heritage Conservation..............................................39 2. National Planning Policy Guidance...............................................................................................................39 3. Local Agenda 21................................................................................................................................................40 4. The Natural Areas Map....................................................................................................................................40 5. Local Biodiversity Action Plan: the UK Steering Group Report..............................................................41 6. The Geological Curators Group.....................................................................................................................41 3 APPENDIX II: HERTFORDSHIRE GEOLOGICAL SSSIs ............................................................................43 APPENDIX III: SOME RELEVANT GEOLOGICAL CONSERVATION ORGANIZATIONS AND INITIATIVES IN HERTFORDSHIRE..................................................................................................................46 1. Local Nature Reserves .....................................................................................................................................46 2. Hertfordshire's Development Plan ................................................................................................................46 3. Thames Northern Tributaries Project..........................................................................................................46 4. Hertfordshire and Middlesex Wildlife Trust...............................................................................................47 5. Hertfordshire Geological Society ..................................................................................................................47 6. Landowners and Managers..............................................................................................................................48 7. Countryside Forum and Countryside Management Service .....................................................................48 APPENDIX IV: HERTFORDSHIRE MUSEUMS AND OTHER INSTITUTIONS WITH GEOLOGICAL COLLECTIONS......................................................................................................................................................49 APPENDIX V: USEFUL ADDRESSES ..............................................................................................................50 APPENDIX VI: SUPPLEMENTARY NOTES ON SOME EXISTING AND POTENTIAL CHALK RIGS SITES ........................................................................................................................................................................52 1. Existing RIGS sites...........................................................................................................................................52 2. Potential RIGS sites .........................................................................................................................................55