Mendip Rocks! Project
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Mendip Rocks! Project Contents 1. Introduction……………………………………………………..2 2. Project area including key sites …..……………………… 3 3. Existing resources and recent activities…………………..8 4. Scoping the Mendip Rocks Project………………………..14 5. Project aims and proposals………………………………...15 6. Project outcomes for the Heritage Lottery Fund………..24 Appendix 1: Project plan Mendip Hills AONB Unit - May 2015 1 1. Introduction A significant amount of academic research has been carried out into the geology and mineral extraction industries of the Mendip Hills but most is not easily accessible or appropriate to the general public. Where there has been interpretation of the geology and related themes it has been fragmented and inconsistent in design and quality. In some cases site information has become dated and needs replacing. Through a number of meetings and consultation events, coordinated by the Mendip Hills AONB Unit, a variety of bodies including community groups, conservation organisations and local authorities have identified what is now known as the Mendip Rocks! Project and for which funding will be sought. The Mendip Rocks! Project aims to promote better understanding of the Mendip Hills geology and the resulting landscape, biodiversity and human history that has taken place, by engaging people in a wide range of activities. The location of the Mendip Rocks! Project is the Mendip Hills taking in both the Area of Outstanding Natural Beauty (AONB) and National Character Area (NCA) 141, a landscape extending from the Bristol Channel in the west to Frome in the east. 2 2. Project area including key sites The striking landform of the Mendip Hills rises abruptly from the flat landscape of the Somerset Levels and Moors to the south. This Carboniferous Limestone ridge, with its more weather-resistant sandstone peaks, illustrates the classic features of a karst landscape, the result of the response of the soluble limestone to water and weathering, creating surface features, complex underground cave and river systems, gorges, dry valleys, surface depressions, swallets, sink holes and fast-flowing springs. Such natural features have interacted with human influences to result in complex ritual, industrial and agricultural landscapes extending from the prehistoric period to modern times. In recognition of being one of England’s finest landscapes the central and western part of the Mendip Hills was designated an Area of Outstanding Natural Beauty in 1972 and also accounts for 53% of the National Character Area Mendip Hills 141. The statutory Mendip Hills AONB Management Plan 2014-19 identifies a range of objectives and actions to conserve and enhance the areas special qualities that include the geology, biodiversity and heritage. The Mendip Hills have long been exploited for their raw materials, and the legacy of the mining and quarrying industries can be seen throughout the area. Many old mined areas and quarries are now Scheduled Monuments, and or valuable nature reserves, and or Sites of Special Scientific Interest . Habitats of particular importance are heathland, acid grassland, calcareous grassland, neutral grassland (meadows), calaminarian grassland (occur on lead mined spoil heaps), purple moor grass and semi -natural ancient woodland with typical Mendip species, ash and lime. The spoil heaps from lead mining provide distinctive Mendip habitats due to the high levels of lead, cadmium and zinc that are toxic to most plants. 3 2.1 Key sites The sites listed alphabetically below, together with land ownership shown in brackets are included in the Project plan (Appendix 1)and are the focus of activities for the proposals 1-8 (page 14). Brean Down (National Trust) Brean Down is an example of a former Carboniferous Limestone island now joined to the mainland as a result Holocene accretion of sand, silt and mud. There is a platform on the north side of Brean Down which may be a raised beach formed at a time when sea level was higher than that of today. The site has been occupied by humans since the late Bronze Age and includes the remains of a Romano-Celtic Temple. At the seaward end is Brean Down Fort which was built in 1865 and then re-armed in the Second World War. Black Down and Burrington (Open Access/ Common land) Black Down is the highest point in the Mendips Hills, rising to 325 m. The summit is underlain by sandstone. The hard sandstone forms the higher ground because it is immune from dissolution and resistant to erosion, and gives rise to acidic, wet, often peaty soils. Burrington Combe is a fine example of a typical Mendip Hills gorge, and provides a well exposed, easily accessible, section through the Carboniferous Limestone sequence. The site includes several caves including Avaline’s Hole the oldest burial site in Britain. Charterhouse and surrounds (Somerset Wildlife Trust, South West Heritage Trust and private farmland). The Charterhouse area has a wealth of interesting geology, and evidence of a formerly extensive lead mining industry. The remains of Roman and Victorian lead workings can be seen around Velvet Bottom and Ubley Warren which include 'gruffy' ground, a local name for uneven mined ground. The area contains worked-out mineral veins known as 'rakes', black glassy slag heaps, round stone-lined 'buddle' pits used for washing the ore, smelting plants, old flues and a complex network of dams and leats. Cheddar Gorge (National Trust and Longleat Estates) Cheddar Gorge is the finest example of a limestone gorge in Britain. The gorge was formed by meltwater floods during the many cold periglacial periods over the last 1.2 million years. During these arctic episodes the caves were blocked with ice and frozen mud. Snowmelt floods during the brief summers were forced to flow on the surface, carving out the gorge in the process. Many of the caves are designated as Scheduled Monuments and cave exploration is on-going. The cliffs support many valuable semi-natural habitats, home to a wide range of plant species, many of them rare, including slender bedstraw and lesser meadow-rue, and the rare and protected Cheddar Pink and are part of the Cheddar Complex Site of Special Scientific Interest (SSSI). A small quarry known locally as Landslip Quarry operated in the gorge until the early 20th century. At the lower end of the gorge is the popular Longleat cave attraction. 4 Crook Peak, Wavering Down and Axbridge Hill (National Trust) The elongate ridge from Crook Peak to Axbridge Hill is formed of Carboniferous Limestone. The southern side of the ridge is indented by several small valleys, many of which follow the lines of earlier Triassic valleys. The Black Rock Limestone is well exposed in a small quarry on the northern side of Crook Peak, in the railway cutting at Shute Shelve and in the many small cliffs on the northern side of the ridge. The overlying Burrington Oolite can be seen in the crags at the top of Crook Peak and in the small disused quarries at the foot of the ridge south of Compton Bishop. The Clifton Down Limestone outcrops in the disused quarry at Cross and in the road cutting at the western end of the Axbridge bypass. East Harptree Woods (Forestry Commission) The Harptree area was an important lead and zinc mining area. Lead ore was mined from veins in the Carboniferous Limestone, and manganese and zinc from veins in the Dolomitic Conglomerate. This has left a legacy of old pits, spoil heaps and shafts creating areas of pockmarked 'gruffy ground' now within a conifer plantation. The lead-rich spoil heaps are home to several rare plant species. Much of the ore was processed and smelted on Smitham Hill where ore dressing and smelting works were built by the East Harptree Lead Works Company in 1867. The Smitham chimney dates from this time and is the last lead-smelting chimney still standing on the Mendip Hills. Mells Valley (private farmland and woodland) The deeply incised valleys between Great Elm and Hapsford are an excellent place to study the local geology. The valley sides here have been extensively quarried, creating some superb exposures of the underlying rock. The quarries along the Egford Book provide good exposures of the steeply dipping Carboniferous Black Rock Limestone. The steep valley sides support a diverse, and nationally rare, ancient woodland that is at least 400 years old and are now rich havens for wildlife, whilst the fast-flowing, clean calcareous waters of the Mells Stream and the Egford Brook support many riparian species. Nettlebridge Valley (Somerset Wildlife Trust and private farmland) The Somerset Coalfield stretches from the Mendip Hills north to Pensford and Timsbury, and is centered around the town of Radstock. It was in this coalfield that William 'Strata' Smith, the so-called 'father of English geology', first put together his ideas on stratigraphy. The southernmost part of the coalfield extends south to the Mendip Hills. Here the Mells River has incised the Nettlebridge valley, cutting through a cap of Dolomitic Conglomerate to expose the Upper Carboniferous Coal Measures beneath. The area contains a wealth of interesting geology, industrial archaeology and wildlife, as well as several nature reserves. Coal was probably worked in Roman times but mining began in earnest in the 1600s. However, the narrow contorted seams made production expensive and competition from more economical coalfields led to the closure of the last remaining pit in 1973. 5 Nunney (private farmland and woodland, the old quarry gardens are owned by the Parish Council, the castle is owned by English Heritage) In the centre of Nunney are the impressive remains of Nunney Castle, built at the end of the 14th century by Sir Elias de la Mere. It was besieged by Cromwell's troops during the Civil War and was dismantled in 1654. The castle, owned by English Heritage, is constructed from the Inferior Oolite and the Great Oolite 'Bath Stone', and is open to the public.