An introduction to the Geological Conservation Review

N.V. Ellis (Editor)

D.Q. Bowen S. Campbell J.L. Knill A.P. McKirdy C.D. Prosser M.A. Vincent R.C.L. Wilson

Published by the Joint Nature Conservation Committee Monkstone House City Road Peterborough PE1 1JY

First edition 1996

ISBN 1 86107 403 4

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library. Recommended citation for this volume:

Ellis, N.V. (ed.), Bowen, D.Q., Campbell, S., Knill, J.L., McKirdy, A.P., Prosser, C.D., Vincent, M.A. and Wilson, R.C.L. (1996) An Introduction to the Geological Conservation Review. GCR Series No. 1, Joint Nature Conservation Committee, Peterborough.

British Geological Survey copyright protected materials

1. The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council. No part of these materials (geological maps, charts, plans, diagrams, graphs, cross-sections, figures, sketch maps, tables, photographs) may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the written permission of the copyright holder, in advance.

2. To ensure that copyright infringements do not arise, permission has to be obtained from the copyright owner. In the case of BGS maps this includes both BGS and Ordnance Survey. Most BGS geological maps make use of Ordnance Survey topography (Crown Copyright), and this is acknowledged on BGS maps. Reproduction of Ordnance Survey materials may be independently permitted by the licences issued by Ordnance Survey to many users. Users who do not have an Ordnance Survey licence to reproduce the topography must make their own arrangements with the Ordnance Survey, Copyright Branch, Romsey Road, Southampton SO9 4DH (Tel. 01703 792913).

3. Permission to reproduce BGS materials must be sought in writing from Dr Jean Alexander, Copyright Manager, British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (Tel. 0115 936 3331).

Page layout and design by: R & W Publications (Newmarket) Ltd

Printed in Great Britain by: Halstan & Co Limited, Amersham, Buckinghamshire

(Front cover)

(Rear cover)

Acknowledgements

Foreword

Chapter 1 The subject and purpose of this volume

Chapter 2 The need for earth heritage conservation

The international significance of Earth heritage sites Exceptional Earth heritage sites

Earth science research

Environmental forecasting

Earth heritage sites in education and training

The Earth heritage as a cultural and ecological resource

Chapter 3 An introduction to the geological history of Britain

The importance of sites

Salisbury Crags and Arthur's Seat, Edinburgh

Barton Cliffs, Hampshire

Islay and Jura, the Inner Hebrides

The geology of Britain

Introduction

The origin of rocks

Sedimentary rocks

Igneous rocks

Metamorphic rocks

Geological time

Some geological patterns

Mountain building episodes

Mountain building and plate tectonics

A geological history of Britain

The Precambrian rocks of Britain

The Cambrian, Ordovician and Silurian rocks of Britain

The Devonian and Carboniferous rocks of Britain

The Permian and Triassic rocks of Britain

The Jurassic and Cretaceous rocks of Britain

The Tertiary rocks of Britain

Quaternary sediments and landforms of Britain

Britain after the last ice age

Present-day Britain

The importance of Britain in the development of geology

Chapter 4 The Geological Conservation Review

Principles of site selection

Aims of the Geological Conservation Review

The first component — international importance

The second component — exceptional features

The third component — representativeness

Geological Conservation Review blocks

Stratigraphy blocks

Palaeontology blocks

Quaternary blocks

Geomorphology blocks

Igneous petrology and structural and metamorphic geology blocks

Mineralogy blocks

Geological Conservation Review networks

Marine Permian Geological Conservation Review block

Durham Province network: the western edge of an inland sea

Yorkshire Province network

Igneous rocks of South-west England Geological Conservation block

Pre-orogenic volcanic network

Cornubian granite batholith network

Post-orogenic volcanic network

Lizard and Start complexes network

Palaeozoic palaeobotany Geological Conservation Review block

Silurian network

Devonian network

Lower Carboniferous network

Upper Carboniferous network Permian network

Quaternary Geological Conservation Review networks: English lowland valley rivers

The coastal geomorphology of Scotland Geological Conservation

Review block

Beach complexes of Scotland

Beaches of the Highlands and Islands networks

Beach–dune–machair system

Beach and dune coasts of lowland Scotland networks

Rock coast geomorphology networks

Saltmarsh geomorphology networks

The Geological Conservation Review site series

Chapter 5 Practical geological conservation review selection methods

Site selection criteria

Minimum number and minimum area of sites

Methods and working practice

Site selection procedures within the Geological Conservation Review

Stage 1: Building and briefing the block team

Stage 2: Literature review and site shortlisting

Stage 3: Field visits and detailed site investigation

Stage 4: Final assessment and preparation of Geological Conservation Review site documents

The study of the Earth — continuing developments

Chapter 6 Earth heritage conservation

Threats to the earth heritage

Quarrying and earth heritage conservation: threats and benefits

The history of Earth heritage conservation in Britain

Earth heritage site protection

The legal framework

Earth heritage conservation in practice

Conservation strategy

Classification of site types

Earth heritage conservation in practice — some examples

Fossil and mineral collecting and conservation

Coastal sites

Conservation of the Barton Geological Conservation Review site

Active quarries

Conservation at Shap Granite Quarry

Disused quarries

Conservation at Ercall Quarry, Shropshire

General considerations at disused quarries

Disused quarries as landfill sites

Cave conservation

Road construction

Conservation of Claverley Road Cutting

Site excavation and specimen curation

The excavation in Brighstone Bay, Isle of Wight

Conservation of active geomorphological process sites

Conservation of the River Dee: a mobile meander belt

Mine dumps

Writhlington Rock Store SSSI

Site 'burial'

Publicity and public awareness

Advice on conservation of Earth heritage sites

Chapter 7 The Geological Conservation Review in the context of the wider earth heritage conservation effort

Earth heritage conservation strategy

Progress and developments in Earth heritage conservation

Maintaining the SSSI series through the mechanism of the Geological Conservation Review

Expanding the RIGS network

Developing conservation techniques Improving documentation

Increasing public awareness

Developing international links

Earth heritage and nature conservation

Appendix

References and further reading

Glossary

Index

Acknowledgements

The Joint Nature Conservation Committee wishes to acknowledge the contribution made by the late Chris Stevens. His guidance and enthusiasm provided a valuable impetus during the early stages of text writing.

Thanks go to those individuals who have written text and made editorial contributions to this volume: Dr P.H. Banham, Mr J.H. Bratton, Dr K.L. Duff, Dr J.L. Eyers, Dr N.F. Glasser, Dr J.E. Gordon, Dr J.G. Larwood, Dr R.G. Lees, Professor J. McManus, Dr T. Moat, Dr D.P.A. O'Halloran, Dr K.N. Page, Dr L.P. Thomas, Mr D.A. White, Dr W.A. Wimbledon and Ms F.J. Wright.

The help of the consultees to the draft of the volume is gratefully acknowledged. Those who commented are too numerous to mention individually, but their contributions proved invaluable in the preparation of the final typescript.

Foreword

In the rocks and landscapes of Britain lies the evidence for ancient events which fashioned the small but complex part of the Earth's crust that we now call the British Isles. By piecing together this evidence, it is possible to construct the geological history of Britain. Magnus Magnusson, the Chairman of Scottish Natural Heritage and one of my colleagues on the Joint Nature Conservation Committee, said that:

'Our geological past involves a barely believable story of whole continents moving around like croutons floating on a bowl of thick soup, of great oceans forming and disappearing like seasonal puddles, of mighty mountains being thrown up and worn down, of formidable glaciers and ice caps advancing and retreating behind mile-thick walls of ice as they melted and reformed again. Scotland has been a desert, a tropical rain forest and a desert again; it has drifted north over the planet with an ever-changing cargo of lizards, dinosaurs, tropical forests, giant redwoods, sharks, bears, lynx, giant elk, wolves and also human beings.

'There is a fascinating story to tell that is of profound relevance to the world.'

What Magnus Magnusson said about the geological history of Scotland is also true for Britain as a whole. There is indeed a fascinating story to tell, although some of the chapters are still far from complete. For the full story to unfold it is vital that the important rocks and landforms of Britain must be protected so that they can provide the necessary scientific resource for future work. And this may well utilise new scientific techniques yet to be discovered.

Britain was the cradle of modern geology, and observations made by British geologists in the eighteenth and nineteenth centuries laid the foundations of the science as we know it today. Many of the sites at which these observations were made continue to be conserved as a part of our national Earth heritage. The contribution that the geology of Britain has made to international science is as important today as it has ever been. British sites are world-renowned for providing the milestones that mark geological time and the benchmarks that define geological principles. There is every reason for us to take a special pride in this unrivalled Earth heritage.

Since the heady, pioneering days in the early development of the Earth sciences, the study of the geology of Britain has continued to provide evidence to construct, and then test, theories about the development of the Earth and the processes that take place within its interior and on its surface. Geology today is as much about the future as it is about the past. By learning about past climates we can understand our present climate system better and thus how to evaluate the impact of future climatic changes.

The geology of Britain has contributed to our national wealth and so influenced our archaeological and industrial inheritance, from the Phoenicians trading for Cornish tin, to the coal and iron which created the Industrial Revolution and, now, to the oil and gas below our coastal seas which is essential to our economic well-being. The geologists of tomorrow, who will discover new economic resources and locate sites for new engineering works all over the world, are being trained in an environment of extraordinary geological quality.

Natural landforms create the environments within which the diverse flora and fauna of Britain live. Rocks provide the soil and influence the drainage conditions of biological habitats. Biological and geological forms and functions are inextricably linked to create a series of natural systems of immense richness and diversity.

Active conservation measures are required to protect the geology and landforms of Britain as an important and irreplaceable scientific, educational, cultural, aesthetic and potentially economic resource. If irreparable damage or loss was to occur then it is our own society that would be impoverished.

Conservation of geological and geomorphological sites has always been part of the responsibilities of the statutory nature conservation agencies. A major initiative to identify and describe the most important geological sites in Britain began in 1977, with the launching of the Geological Conservation Review. This book provides a description of the methods and practice of the Review, as well as a background account of the geological history of Britain which demonstrates clearly why the Earth heritage of this country is so important.

I am confident that this book will be an invaluable reference for those who wish to understand the Geological Conservation Review and for those who need to manage our extraordinarily diverse Earth heritage.

Selbourne [signature]

The Earl of Selborne KBE FRS

Chairman, Joint Nature Conservation Committee

(Frontispiece)

Introduction to the Geological Conservation review [Rear cover]

The purpose of this book is to explain why Britain's Earth heritage is important and how the national series of Earth heritage sites was identified in the Geological Conservation Review. It also describes how these sites are protected by law and how they are conserved.

This volume is intended primarily for all those with an interest in managing the land: owners and occupiers, managers, planners and those involved in the waste disposal, mineral extraction, construction and coastal engineering industries. It will also be of interest to professional and amateur Earth scientists, conservationists, and teachers, lecturers and students of the Earth sciences.

The aim of the Geological Conservation Review Series is to provide a public record of the features of inter est an importance at localities already notified, or being considered for notification, as 'Sites of Special Scientific Interest' (SSSIs). All 42 volumes in the series are written to the highest scientific standards and incorporate the cumulative insights of generations of leading Earth scientists, in such a way that the assessment and conservation value of the sites is clear. This volume is the introduction to the Series.

The geology of south-west England gives rise to some of Britain's most spectacular landscape and rich miner al resources, ranging from tin to china clay and building stones. The scientific study of the rocks in this region has yielded greater understanding of how northern Europe underwent a period of mountain building some 300 million years ago. These immense earth movements were accompanied by the emplacement into the existing country rocks of vast bodies of molten igneous rock which cooled to form granite. The photograph shows Haytor Rocks, Dartmoor, an excellent area in which to examine the textural and compositional variations in the main suite of Dartmoor granites. This is the reason for the selection of the site as a Geological Conservation Review site. The Dartmoor granite is also renowned for dramatic tor scenery and Haytor is widely visited as a classic example of such a landscape. Photograph by: S. Campbell

Joint Nature Conservation Committee, Peterborough