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Totternhoe Stone
250 px, The characteristic checkerboard design of many Bedfordshire churches built with alternating chalk and flint blocks: St Mary's (Luton). Totternhoe Stone is a relatively hard chalk outcropping in the middle of the Lower Chalk in the Chiltern Hills in Hertfordshire, Buckinghamshire, Bedfordshire and Cambridgeshire, England. Geologically, it is located in the upper part of the Cenomanian stage of the Cretaceous. Unusually among chalks, it is sufficiently strong for use as a building stone, and has been used as such in these localities, notably in Woburn Abbey, Luton parish church and several smaller local churches. It weathers rather badly in external use, but when used as internal carved decoration, it has remained in good condition for centuries. Old decorative carving is to be found in St Albans Abbey and in the altar screen of Westminster Abbey. The Totternhoe Stone is underlain by the argillaceous Chalk Marl. Above is the less argillaceous Grey Chalk. The bed v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Lime
Hydraulic lime (HL) is a general term for calcium oxide, a variety of lime also called quicklime, that sets by hydration. This contrasts with calcium hydroxide, also called slaked lime or air lime that is used to make lime mortar, the other common type of lime mortar, which sets by carbonation (re-absorbing carbon dioxide (CO2) from the air). Hydraulic lime provides a faster initial set and higher compressive strength than air lime, and hydraulic lime will set in more extreme conditions, including under water. The terms 'hydraulic lime' and 'hydrated lime' are quite similar and may be confused but are not necessarily the same material. Hydrated lime is any lime which has been slaked whether it sets through hydration, carbonation, or both. Calcium reacts in the lime kiln with the clay minerals to produce silicates that enable some of the lime to set through hydration. Any unreacted calcium is slaked to calcium hydroxide which sets through carbonation. These are sometimes called 's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Online Computer Library Center
OCLC, Inc., doing business as OCLC, See also: is an American nonprofit cooperative organization "that provides shared technology services, original research, and community programs for its membership and the library community at large". It was founded in 1967 as the Ohio College Library Center, then became the Online Computer Library Center as it expanded. In 2017, the name was formally changed to OCLC, Inc. OCLC and thousands of its member libraries cooperatively produce and maintain WorldCat, the largest online public access catalog (OPAC) in the world. OCLC is funded mainly by the fees that libraries pay (around $217.8 million annually in total ) for the many different services it offers. OCLC also maintains the Dewey Decimal Classification system. History OCLC began in 1967, as the Ohio College Library Center, through a collaboration of university presidents, vice presidents, and library directors who wanted to create a cooperative, computerized network for libraries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Conservation Review
The Geological Conservation Review (GCR) is produced by the UK's Joint Nature Conservation Committee and is designed to identify those sites of national and international importance needed to show all the key scientific elements of the geological and geomorphological features of Britain. These sites display sediments, rocks, minerals, fossils, and features of the landscape that make a special contribution to an understanding and appreciation of Earth science and the geological history of Britain, which stretches back more than three billion years. The intention of the project, which was devised in 1974 by George Black and William Wimbledon working for the Governmental advisory agency, the Nature Conservancy Council (NCC), was activated in 1977. It aimed to provide the scientific rationale and information base for the conservation of geological SSSIs (Sites of Special Scientific Interest, protected under British law (latterly the Wildlife and Countryside Act 1981, as amended 1995). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Totternhoe Stone Pit
Totternhoe Stone Pit is a geological Site of Special Scientific Interest in Totternhoe in Bedfordshire, England. It is also a Geological Conservation Review site, and the local planning authority is Central Bedfordshire Council. The site displays the base of the Totternhoe Stone. It is a lime mud with an extensive deposit of late Cretaceous shark teeth, some of species which have not been fully described, so it will be an important resource for further research. The lower levels contain larger teeth, and in upper ones there are some small rays. The site is part of the Totternhoe nature reserve, managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire The Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire (WTBCN) is a registered charity which manages 126 nature reserves covering . It has over 35,000 members, and 95% of people in Bedfordshire, Cambridgeshire and Northamptonshi ..., but there is no public access to the Stone Pit. Refere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildlife Trust For Bedfordshire, Cambridgeshire And Northamptonshire
The Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire (WTBCN) is a registered charity which manages 126 nature reserves covering . It has over 35,000 members, and 95% of people in Bedfordshire, Cambridgeshire and Northamptonshire live within five miles of a reserve. In the year to 31 March 2016 it employed 105 people and had an income of £5.1 million. It aims to conserve wildlife, inspire people to take action for wildlife, offer advice and share knowledge. The WTBCN is one of 36 wildlife trusts covering England, and 46 covering the whole of the United Kingdom. In 1912 Charles Rothschild formed the Society for the Promotion of Nature Reserves to protect sites considered "worthy of preservation". The society worked to secure statutory protection, and this began with the National Parks and Access to the Countryside Act 1949. In 1959 the society took on a coordinating role for local wildlife trusts, which covered the whole of Britain and Northern Ireland by 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature Reserve
A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or other special interest, which is reserved and managed for purposes of conservation and to provide special opportunities for study or research. They may be designated by government institutions in some countries, or by private landowners, such as charities and research institutions. Nature reserves fall into different IUCN categories depending on the level of protection afforded by local laws. Normally it is more strictly protected than a nature park. Various jurisdictions may use other terminology, such as ecological protection area or private protected area in legislation and in official titles of the reserves. History Cultural practices that roughly equate to the establishment and maintenance of reserved areas for animals date bac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcareous Grassland
Calcareous grassland (or alkaline grassland) is an ecosystem associated with thin basic soil, such as that on chalk and limestone downland. Plants on calcareous grassland are typically short and hardy, and include grasses and herbs such as clover. Calcareous grassland is an important habitat for insects, particularly butterflies and ants, and is kept at a plagioclimax by grazing animals, usually sheep and sometimes cattle. Rabbits used to play a part but due to the onset of myxomatosis their numbers decreased so dramatically that they no longer have much of a grazing effect. There are large areas of calcareous grassland in northwestern Europe, particularly areas of southern England, such as Salisbury Plain and the North and South Downs. The machair forms a different kind of calcareous grassland, where fertile low-lying plains are formed on ground that is calcium-rich due to shell sand (pulverised sea shells). See also * Alvar * Chalk heath * Edaphic * Gypcrust * Gypsum flora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Totternhoe Chalk Quarry
Totternhoe Chalk Quarry is a biological Site of Special Scientific Interest in Totternhoe in Bedfordshire. Part of it lies in Totternhoe nature reserve, which is managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire. The site is part of the Chilterns Area of Outstanding Natural Beauty. The site is a disused medieval quarry for Totternhoe stone, a durable chalk which was used for buildings including Westminster Abbey. The steeply sloping spoil heaps have developed into grasslands which have a wide variety of flowers, including orchids. Grass chalkland is a habitat under threat, and the site has a number of rare plant species, including great pignut. It also has butterflies such as the chalkhill blue and the nationally rare Duke of Burgundy Duke of Burgundy (french: duc de Bourgogne) was a title used by the rulers of the Duchy of Burgundy, from its establishment in 843 to its annexation by France in 1477, and later by Holy Roman Emperors and King ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Site Of Special Scientific Interest
A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle of Man. SSSI/ASSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in the United Kingdom are based upon them, including national nature reserves, Ramsar sites, Special Protection Areas, and Special Areas of Conservation. The acronym "SSSI" is often pronounced "triple-S I". Selection and conservation Sites notified for their biological interest are known as Biological SSSIs (or ASSIs), and those notified for geological or physiographic interest are Geological SSSIs (or ASSIs). Sites may be divided into management units, with some areas including units that are noted for both biological and geological interest. Biological Biological SSSI/ASSIs may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medieval
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the Post-classical, post-classical period of World history (field), global history. It began with the fall of the Western Roman Empire and transitioned into the Renaissance and the Age of Discovery. The Middle Ages is the middle period of the three traditional divisions of Western history: classical antiquity, the medieval period, and the modern history, modern period. The medieval period is itself subdivided into the Early Middle Ages, Early, High Middle Ages, High, and Late Middle Ages. Population decline, counterurbanisation, the collapse of centralized authority, invasions, and mass migrations of tribes, which had begun in late antiquity, continued into the Early Middle Ages. The large-scale movements of the Migration Period, including various Germanic peoples, formed new kingdoms in what remained of the Western Roman Empire. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic viability of investing in the equipment, labor, and energy required to extract, refine and transport the materials found at the mine to manufacturers who can use the material. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
