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The Dry Stone Walling Association of Great Britain

This charitable organisation was founded The geological history of the in 1968 to ensure that the best of walling THE GEOLOGICAL British Isles is very complicated. DRY STONE WALLS and dyking craftsmanship is preserved LANDSCAPE The map has been simplified • are found mainly in the higher areas to the north and promoted. to show only the main outcrops and west of Britain ® of geological eras and their Further information about the DSWA are made with stone collected or quarried locally GEOLOGICAL ERAS principal rock types. • and its activities is available by post or run for over 200,000 kms (125,000 miles) in the UK on the website. TERTIARY - CRETACEOUS A • Sedimentary: Clays, sands & chalk Wall Locations will survive for centuries with careful maintenance Walls The Dry Stone Walling Association • JURASSIC - TRIASSIC - PERMIAN A Scottish Highlands mark out boundaries & the of Great Britain, CARBONIFEROUS - DEVONIAN • Sedimentary: Westmorland County Showground, B Central Scotland provide security and shelter for stock Lane Farm, Crooklands, Milnthorpe, Limestones, sandstones & coal B • Landscape , LA7 7NH SILURIAN - ORDOVICIAN - CAMBRIAN C S.W. Scotland offer a haven for a variety of wildlife Sedimentary: • a guide to Slates, mudstones & sandstones are usually called dykes in Scotland Tel: 015395 67953 D • British walls email: [email protected] D E Cumbria – Eden Valley WHY DO WALLS LOOK DIFFERENT? C and West coast E website: www.dswa.org.uk F G H F Cumbria – Skiddaw Walls differ throughout Britain because of the way rocks have been formed. BUILDING A DRY STONE WALL I Registered charity: 289678 J • The rock’s composition, shape and size determines the way it can be G Cumbria split or shaped. Borrowdale - volcanic E The Association is grateful for support K • Walls display the characteristics of the geology forming their landscapes. from the following stone suppliers in the H Cumbria • Rocks to the south and east are generally softer, less exposed and often not preparation of the Crooklands Walling L Borrowdale - river cobble as suitable for building walls. Exhibition and its associated publication: I Cumbria - Brathay Aaon Agri Hire, Dalbeattie J Cumbria - S. Lakeland D Balblair Quarry, Beauly M Celtic Pennant Stone, South Wales K W. C PRECAMBRIAN N B B Denfind Stone Ltd, Angus Metamorphic: L A Foundation Downs Stone Company Ltd, Quartzite, schist, gneiss & slate B Building stones C Hearting/packing Dunhouse Quarry Co Ltd, Co Durham M Cotswolds D Throughstones E Copestones A Gwrhyd Specialist Stone Quarry, South Wales SCULPTING THE LANDSCAPE Igneous - Intrusive & Extrusive: N S. Wales Johnson Wellfield Quarries Ltd, Granite & basalt Rocks beneath Kirkstone Quarries Ltd, Ambleside the surface form THE ROCK CYCLE - forming and reforming the landscape Natural Stone Merchants, South Yorkshire the skeleton of Roland Stone, Cumbria IGNEOUS ROCK the landscape. The many different ways of formed by molten magma from deep in the A & J Wilson, Lockerbie forming and reforming rocks earth flowing upwards through other rocks have created three creating intrusive rocks, later exposed The formation by erosion; or volcanic eruptions distinct types. producing lava flows and and weathering ash deposits known of each type has as extrusive rocks. its effect on what we see today. This project is being partly financed by the European Agriculture Guidance and Guarantee Fund of the European Union and the Rocks are constantly undergoing change. Older rocks are Department for Environment Food and Rural GEOLOGICAL TIMESCALE broken down to produce younger rocks in continuous cycle. Affairs through the Cumbria Fells and Dales MA = million years The coloured columns relate to the Geological Map of the British Isles Many processes affect these changes: LEADER+programme. 65 MA to today TERTIARY Soft rocks in S.E. . Volcanic rocks in W Scotland movements of plates on the Earth’s crust allowing 142 to 65 MA CRETACEOUS Greensands, chalk: S.E. England, Yorkshire • 205 to 142 MA JURASSIC Limestones, shales: to N.Yorkshire coasts molten rock to well up from deep in the earth 290 to 205 MA TRIASSIC & PERMIAN Magnesian Limestone, New Red Sandstone, conglomerates: volcanoes showering the land with ash and lava , Midlands, E&W. , N&E. Lake District, Scottish Borders • © DSWA 2006 354 to 290 MA CARBONIFEROUS Limestone, Millstone Grit, Coal Measures, sandstones: dramatic earth movements shifting continental sized S.Wales, Pennines, Cumbria, , Midland Valley of Scotland, • areas of land Photographic credits: Mid- 417 to 354 MA DEVONIAN Sandstone, conglomerates, shales. Granite intrusions in Scotland: I.Brodie, P.Clark, P.Cauthery, DSWA, mountain building movements, squeezing, twisting, and S. Devon, Old Red Sandstone in S. Wales, N. Devon, • D.Goulder, R.Ingles, Midland Valley of Scotland, Moray Firth, Caithness and Orkney thrusting and tilting the land Northumberland National Park Authority, 495 to 417 MA ORDOVICIAN Shales, mudstones, some limestones. Granite intrusions and volcanic rocks: climatic changes creating scorching deserts and & SILURIAN Mid-Wales into Pembrokeshire and Denbighshire, Central & S.Lake District, • SEDIMENTARY ROCK METAMORPHIC ROCK R.Reid, J.Riddick, A.Shaw, Southern Uplands. Igneous activity in Scottish Highlands frozen wastes formed when eroded formed when other K.& D. Sorrell, T.Wragg, K.Young. 545 to 495 MA CAMBRIAN Shales, slates, gritstones: Harlech Dome, Malverns, N. Pembrokeshire, particles of other rocks, rocks are subjected to high N.W. Highlands. weathering by wind, and water over millions pebbles, animal or organic temperatures and pressure • matter are deposited in layers and recrystallized. Display boards by Pandora Signs Over 545 MA PRECAMBRIAN Gneisses, schists, sandstones, conglomerates, siltstone: of years Grampians & N. Highlands of Scotland. in water or in desert environments changing their and then compacted under pressure. texture. Rock Cycle & Design © Sorrell Design Volcanic activity occurs throughout Granite & basalt: Anglesey, Charnwood - , glacial action in northern parts of Britain the geological history of the Earth Long Mynd - • • depositing and compacting of marine sediments Follow the arrows to see how changes occur over the years