Alfreton is a town and civil parish in Amber Valley, Derbyshire based in the East Midlands, adjoining the Bolsover and North East Derbyshire districts. It was a Norman Manor and an Urban District; the population of the Alfreton parish was 7,971 at the 2011 Census. The villages of Ironville, Riddings and Swanwick were part of the Manor and Urban District, the population including these was 24,476 in 2001. Alfreton is said to have derived its name from him; the placename appears in different forms throughout the ages, such as'Elstretune' in Domesday, but the earliest appears to be in AD1004 in the will of Wulfric Spott, the founder of Burton Abbey. Amongst his bequests was'Aelfredingtune', or'Alfred's farmstead', believed to relate to Alfreton; however there is no evidence. To the south-west near Pentrich was a Roman fortlet on the major road known as Ryknield Street. Another Roman road known as Lilley Street ran from there to the southern end of Alfreton, suggesting that settlement in the area predated the time of King Alfred by several centuries.
The initial settlement was centred at the top of the modern King Street hill, where the original market place developed. On the hilltop there was an ancient meeting hall until 1914, several inns became established over the centuries, some of which survive today. To the west was a manor house, the nearby Church of St. Martin, parts of which date back to 1200; the manor of Alfreton spread over lands to the south and east, including the parishes of Somercotes, Swanwick and Ironville. The first Lord of the Manor was Earl Roger de Busli, who delegated the position to Baron Ralf Ingram; the position was passed down variously through heredity and sale over the centuries up until William Palmer-Morewood, the last Lord of Alfreton, who died in 1957. The economy during the medieval period was centred on agriculture. However, the presence of accessible and extensive deposits of coal and ironstone in the area meant that mining and iron-working grew in importance. In some parts of the manor coal seams were so close to the surface they were ploughed up, numerous small workings developed.
Pits developed with those in Swanwick and Alfreton being the most productive. Alfreton colliery was sited to the north-east of the town. Rope-making was allied to this industry, the locality became famous for the quality of its ropes. In the 18th century Alfreton was the chief coal-mining centre in Derbyshire, the third-largest town in the county; the pits closed in the late 1960s and their sites have been reclaimed for other development. Local iron working began in the low-lying land to the south of the current town in the vicinity of the A61, where a dam was made to power a water mill; this would have been quite a small operation, along with another at Lower Birchwood, it was not until the 18th century that iron working was expanded into major enterprises, centred on Riddings and Butterley in the south and south-east of the manor. The growth of these industries formed the basis of the area's prosperity, attracted huge numbers of workers in the 19th century swelling the local population; the extensive brick terraced housing in the area dates to this period, brick-making and tile-making were significant local industries.
Boot-making and repairing, tanning of leather, were substantial employers due to the need for footwear for these heavy industries. According to Census figures, in 1801 the population of the area that would become the Urban District stood at 2,301, rising to 21,232 in 1931, it has remained within about 3,000 of that number since. After the closure of the pits and Riddings Ironworks in the 1960s, local employment shifted to factory and service-based enterprises, many of which grew up on industrial estates occupying despoiled colliery lands. Only a few major employers were present, such as Aertex and English Rose, but this was to change with the development of several industrial estates to the east of the town; the development of transport in the area followed much the same pattern as elsewhere in England, with roads being vastly improved by turnpiking from the late 18th century onwards. Turnpike Acts affecting the area were obtained in 1759, 1764, 1786 and 1802; these provided Alfreton with good road links to Derby, Mansfield and the High Peak.
The town became a coaching centre, which accounts for the inordinate number of inns that were in the vicinity of the market place. A legal requirement on turnpike companies to provide milestones resulted in a local curiosity, a cast-iron marker on the town cross-roads with the notation'Alfreton 0 Miles'. Around the same time as turnpikes were introduced the coal and iron industries benefited from the building of canals in the southern and eastern parts of the area; the Cromford Canal was built in 1793, had a 3,000-yard long tunnel. In the 19th century and canal transport were rendered obsolete by railways built to the east of the town and along the eastern and southern boundaries of the former manor; the canals fell into disuse, road and rail transport burgeoned. Rail underwent a temporary decline in the 1960s due to the Beeching cuts, which included the Alfreton station, re-opened in the 1970s. Alfreton Hall was the successor to the original manor house, was built c.1750, with an additional wing added c.1850.
Alfreton House is now occupied by the Town Council. The former George Inn at the top of King Street
Millers Dale railway station
Millers Dale railway station was situated in Millers Dale in the Peak District. It was built in 1863 by the Midland Railway on its extension of the Manchester, Buxton and Midlands Junction Railway from Rowsley, it served an important junction where passengers for Buxton joined or left the trains between London and Manchester. It was to be called "Blackwell Mill" but, in the end, was named "Millers Dale for Tideswell". For such a rural location, it was unusually large. Millers Dale sent dairy and quarried products from the surrounding areas to the major cities. While serving local towns and villages—notably Tideswell and Wormhill—much of its activity was concerned with the connecting service to and from Buxton. Traffic for Buxton followed the main line north for nearly two miles, before diverging at Millers Dale Junction, beside Blackwell Mill Halt. Built on a shelf carved out of the hillside, Millers Dale station had two platforms, but a bay platform was added in 1905 to accommodate Buxton trains, plus the down platform became an island platform to serve the extra tracks.
The new loop and the second viaduct were opened on 20 August 1905. The old viaduct was closed and reopened in April 1906. Whilst the piers for the two viaducts are identical, the older viaduct is supported by an arch structure, whereas the one is a box structure. Part of the original Parliamentary Act approving the line considered the needs of invalids taking the waters at Buxton, so, for a while,'through' carriages for Buxton were attached to, detached from, thus alleviating the problem of changing trains. In addition, the two main platforms were connected by a subway. Changing at Millers Dale involved a wait, the High Peak News of November 1900 referred to the station as "Patience Junction"; the station was immortalised in the 1964 song "Slow Train" by Flanders and Swann. The station closed in 1967 but trains continued to pass through the station until 1968 when the line was closed. Since the railway was closed the station has become a car park serving the Monsal Trail, although the main buildings remain, being used as public toilets.
The hamlet of Millers Dale is still dominated by the two large disused viaducts over the Wye valley. The older of the viaducts today forms part of an 8.5-mile walking and cycle track. The station building is due to reopen as a café and visitor centre in March 2019 after undergoing an extensive £230,000 restoration, providing additional services to users of Monsal Trail. To the north of the station, the line crossed the Wye three times and ran through the 401 yards and 94 yards Chee Tunnels and the 121 yards Rusher Hall tunnel, before reaching the New Mills line junction, 1.25 miles from the station. Cycleways in England Ingenious.org Millers Dale Viaduct, 1892 "Picture the Past" Midland railway station 1964 Disused stations: Millers Dale Millers Dale station on navigable 1947 O. S. map
England is a country, part of the United Kingdom. It shares land borders with Wales to Scotland to the north-northwest; the Irish Sea lies west of England and the Celtic Sea lies to the southwest. England is separated from continental Europe by the North Sea to the east and the English Channel to the south; the country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Palaeolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century, since the Age of Discovery, which began during the 15th century, has had a significant cultural and legal impact on the wider world; the English language, the Anglican Church, English law – the basis for the common law legal systems of many other countries around the world – developed in England, the country's parliamentary system of government has been adopted by other nations.
The Industrial Revolution began in 18th-century England, transforming its society into the world's first industrialised nation. England's terrain is chiefly low hills and plains in central and southern England. However, there is upland and mountainous terrain in the west; the capital is London, which has the largest metropolitan area in both the United Kingdom and the European Union. England's population of over 55 million comprises 84% of the population of the United Kingdom concentrated around London, the South East, conurbations in the Midlands, the North West, the North East, Yorkshire, which each developed as major industrial regions during the 19th century; the Kingdom of England – which after 1535 included Wales – ceased being a separate sovereign state on 1 May 1707, when the Acts of Union put into effect the terms agreed in the Treaty of Union the previous year, resulting in a political union with the Kingdom of Scotland to create the Kingdom of Great Britain. In 1801, Great Britain was united with the Kingdom of Ireland to become the United Kingdom of Great Britain and Ireland.
In 1922 the Irish Free State seceded from the United Kingdom, leading to the latter being renamed the United Kingdom of Great Britain and Northern Ireland. The name "England" is derived from the Old English name Englaland, which means "land of the Angles"; the Angles were one of the Germanic tribes that settled in Great Britain during the Early Middle Ages. The Angles came from the Anglia peninsula in the Bay of Kiel area of the Baltic Sea; the earliest recorded use of the term, as "Engla londe", is in the late-ninth-century translation into Old English of Bede's Ecclesiastical History of the English People. The term was used in a different sense to the modern one, meaning "the land inhabited by the English", it included English people in what is now south-east Scotland but was part of the English kingdom of Northumbria; the Anglo-Saxon Chronicle recorded that the Domesday Book of 1086 covered the whole of England, meaning the English kingdom, but a few years the Chronicle stated that King Malcolm III went "out of Scotlande into Lothian in Englaland", thus using it in the more ancient sense.
According to the Oxford English Dictionary, its modern spelling was first used in 1538. The earliest attested reference to the Angles occurs in the 1st-century work by Tacitus, Germania, in which the Latin word Anglii is used; the etymology of the tribal name itself is disputed by scholars. How and why a term derived from the name of a tribe, less significant than others, such as the Saxons, came to be used for the entire country and its people is not known, but it seems this is related to the custom of calling the Germanic people in Britain Angli Saxones or English Saxons to distinguish them from continental Saxons of Old Saxony between the Weser and Eider rivers in Northern Germany. In Scottish Gaelic, another language which developed on the island of Great Britain, the Saxon tribe gave their name to the word for England. An alternative name for England is Albion; the name Albion referred to the entire island of Great Britain. The nominally earliest record of the name appears in the Aristotelian Corpus the 4th-century BC De Mundo: "Beyond the Pillars of Hercules is the ocean that flows round the earth.
In it are two large islands called Britannia. But modern scholarly consensus ascribes De Mundo not to Aristotle but to Pseudo-Aristotle, i.e. it was written in the Graeco-Roman period or afterwards. The word Albion or insula Albionum has two possible origins, it either derives from a cognate of the Latin albus meaning white, a reference to the white cliffs of Dover or from the phrase the "island of the Albiones" in the now lost Massaliote Periplus, attested through Avienus' Ora Maritima to which the former served as a source. Albion is now applied to England in a more poetic capacity. Another romantic name for England is Loegria, related to the Welsh word for England and made popular by its use in Arthurian legend; the earliest known evidence of human presence in the area now known as England was that of Homo antecessor, dating to approximate
The River Wye is the fifth-longest river in the UK, stretching some 215 kilometres from its source on Plynlimon in mid Wales to the Severn estuary. For much of its length the river forms part of the border between Wales; the Wye Valley is an Area of Outstanding Natural Beauty. The Wye is important for nature recreation; the meaning of the name is not clear. The earliest reference to the name is Guoy in Nennius' early 9th Century Historia Brittonum and the modern Welsh name is Gwy; the Wye was much given a Latin name Vaga, an adjective meaning'wandering'. The Tithe map references a Vagas Field in both Chepstow. Philologists such as Edward Lye and Joseph Bosworth in the 18th and early 19th centuries suggested an Old English derivation from wæg, "wave"; the source of the Wye is in the Welsh mountains at Plynlimon. It flows through or past several towns and villages including Rhayader, Builth Wells, Hay-on-Wye, Ross-on-Wye, Symonds Yat and Tintern, meeting the Severn estuary just below Chepstow, its total length is 134 miles.
The lower 16 miles of the river from Redbrook to Chepstow forms the border between England and Wales. The River Wye forms two Sites of Special Scientific Interest, one covering the Upper Wye above Hay-on-Wye, one covering the Lower Wye downstream to Chepstow; the criteria for inclusion of the river as an SSSI include geology, flora, invertebrates and birdlife, as the river and its tributaries constitute a large linear ecosystem. The Lower Wye SSSI is itself divided into seven units of assessment set by Natural England, administrative responsibilities are shared between the county authorities of Powys, Herefordshire and Monmouthshire; the Wye abuts a range of other SSSIs in England and Wales, including the Upper Wye Gorge and Lower Wye Gorge. It is a Special Area of Conservation and one of the most important rivers in the UK for nature conservation, it is an important migration route and wildlife corridor, as well as a key breeding area for many nationally and internationally important species.
The river supports a range of species and habitats covered by European Directives and those listed under Schedule 5 of the Wildlife and Countryside Act 1981. In Powys the river lies within the Radnorshire Environmentally Sensitive Area. Much of the lower valley is an Area of Outstanding Natural Beauty; the Lower Wye has been designated as a salmonid fishery under the EC Freshwater Fish Directive. The Wye is unpolluted and used to be considered one of the best rivers for salmon fishing in the United Kingdom, outside Scotland. In the 1980s and 1990s salmon in the Wye declined dramatically. In 1967 the Wye rod catch was 7,864, as as 1988 it was 6,401, it is now recovering from this low in response to the extensive habitat improvement work carried out by the Wye and Usk Foundation, set up to restore the spring salmon runs. In 2015 the five-year average once again climbed above 1,000 and it is now the third best salmon river in England and Wales, surpassed only by the Tyne and Wear; the Wye was famous for its large "spring" salmon that had spent three or more years at sea before returning to spawn.
They used to enter the river between January and June and sometimes reached weights of over 50 pounds, the largest recorded being 59 lb 8 oz landed after a long fight by Miss Doreen Davey from the Cowpond Pool at Winforton on 13 March 1923. The last recorded 50 lb rod-caught salmon from the Wye was taken in 1963 by Donald Parrish and weighed 51 lb 8 oz. Since the early 2000s the spring catch has been recovering and salmon of over 35 lb have been reported every year since 2011; the Romans constructed a bridge of stone just upstream of present-day Chepstow. The River Wye was and still is navigable up to Monmouth at least since the early 14th century, it was improved from there to a short distance below Hereford by Sir William Sandys in the early 1660s with locks to enable vessels to pass weirs. According to Herefordshire Council Archaeology, these were flash locks; the work proved to be insufficiently substantial and in 1696 a further Act of Parliament authorised the County of Hereford to buy up and demolish the mills on the Wye and Lugg.
All locks and weirs were removed, except that at New Weir forge below Goodrich, which survived until about 1815. This was paid for by a tax on the county. Weirs were removed all along the Wye in Herefordshire, making the river passable to the western boundary, beyond it at least to Hay on Wye. A horse towing path was added in 1808, but only up to Hereford. Money was spent several times improving the River Lugg from Leominster to its confluence with the Wye at Mordiford, but its navigation is to have been difficult; the Wye remained commercially navigable until the 1850s. It is still used by pleasure craft. In 2017 MORE than 600 people took to the River Wye in inflatables ranging from dinghies to paddling pools during the event WYE FLOAT, opened by former Olympic ski jumper Eddie the Eagle; the Environment Agency is the navigation authority for the river. The Normal Tidal Limit of the river is Bigsweir and navigation below this point is under the control of the Gloucester Harbour Trustees as Competent Harbour Authority.
There is a public right of navigation downstream from Hay-on-Wye. Canoes are permitted at and downstream of Glasbury, so long as they do not disturb anglers; the River Wye provides for canoeing and kayaking as it has sections
Bakewell is a small market town and civil parish in the Derbyshire Dales district of Derbyshire, well known for the local confection Bakewell pudding. It is located about thirteen miles southwest of Sheffield. In the 2011 census the civil parish of Bakewell had a population of 3,949; the town is close to the tourist attractions of Haddon Hall. Although there is evidence of earlier settlements in the area, Bakewell itself was founded in Anglo Saxon times, when Bakewell was in the Anglian kingdom of Mercia; the name Bakewell means a spring or stream of a man named Badeca and derives from this personal name plus the Old English wella. In 949 it was Badecanwelle and in the 11th century Domesday Book it was Badequelle. Bakewell Parish Church, a Grade I listed building, was founded in 920 and has a 9th-century cross in the churchyard; the present church was constructed in the 12th and 13th centuries but was rebuilt in the 1840s by William Flockton. By Norman times Bakewell had gained some importance: the town and its church being mentioned in the Domesday Book and a motte and bailey castle was constructed in the 12th century.
A market was established in 1254, Bakewell developed as a trading centre. The Grade I listed five-arched bridge over the River Wye was constructed in the 13th century, is one of the few surviving remnants of this earlier period. A chalybeate spring was discovered, a bath house built in 1697; this led to an 18th-century bid to develop Bakewell as a spa town, in the manner of Buxton. The construction of the Lumford Mill by Richard Arkwright in 1777 was followed by the rebuilding of much of the town in the 19th century. Bakewell is in the valley of the River Wye in central Derbyshire; the town centre is sited near the river at about 410 feet above sea-level, with the highest parts of the town at about 607 feet on the valley sides. The town is in the Derbyshire Dales district and is about 13 miles southwest of Sheffield, 31 miles southeast of Manchester, 21 miles north of Derby. Nearby towns include Matlock to the south east, Chesterfield to the east and Buxton to the west northwest. Villages near Bakewell include Ashford-in-the-Water, Great Longstone, Over Haddon, Rowsley, Pilsley and Baslow.
Bakewell attracts many international tourists. Monday is popular with visitors; the cattle market is housed in a new purpose built agricultural centre, across the river from the main part of the town. A medium-sized stall market is held in the town centre. A major employer within the town is the Peak District National Park Authority, based at Aldern House on Baslow Road; the National Park Authority is tasked with conserving and enhancing, as well as promoting understanding and enjoyment, of the local area. Opposite Aldern House is another major employer, Newholme Hospital, an NHS cottage hospital providing outpatient clinic services to the local community. A campaign in the town, involving local tradespeople, has failed to prevent the establishment of a branch of Costa Coffee in the town. All Saints' Church is a Grade I listed church founded in 920, during Saxon times and the churchyard has two Saxon crosses. One cross is the Beeley Cross, dug up in a field at a disputed location near Beeley and moved for some years to the grounds of Holt House near Darley Bridge.
Although only the base and lower part of the shaft survive, it stands over five feet high and is carved on all four faces. The other cross is the Bakewell Cross, eight feet high and complete, it was carved in the 7th or 8th century and shows a number of scenes including one of the Annunciation. This cross may have stood at Hassop Cross Roads, although there is no firm evidence for this. During restoration work, in the 1840s, many carved fragments of Saxon stonework were found in and around the porch, as well as some ancient stone coffins; the church contains a selection of cross fragments and carved stones collected by Thomas Bateman and donated to Weston Park Museum in Sheffield before being moved to Bakewell in 1899. There is a notable alabaster memorial to Sir Godfrey de Foljambe, who acquired the manor of Bakewell about 1350, his wife Avena. In 1862, the Manchester, Buxton and Midlands Junction Railway opened Bakewell railway station; the line became part of the Midland Railway and the LMS main line from London to Manchester.
John Ruskin objected to what he saw as the desecration of the Derbyshire countryside, all so that "a Buxton fool may be able to find himself in Bakewell in twelve minutes, vice versa." In return for the Duke of Rutland's permission for the line to pass through his estate at Haddon Hall, the Bakewell station buildings, located on the hillside overlooking the town, are more imposing than a small town might be thought to justify, the Duke's coat of arms are carved into the stonework. Such pandering to the nobility and landowners, was typical of the time, since their support would be necessary to obtain the Act of Parliament though the inconvenient high contour of the railway, which forced the station to be placed out of town, was due to the Duke insisting that the line ran out of sight of Haddon Hall; the station buildings are now used for small businesses, because the line between Matlock and Buxton closed in 1968: most of the trackway has now been designated the Monsal Trail, a quiet motor-traffic-free track for walking and horseriding.
"Normal" trains now run from Derby via Ambergate only as far as Matlock, from Manchester only as far as Buxton. There have been repeated proposals for reopening the remaining, Wye Valley, portion of the line, which would run through Ba
Fire services in the United Kingdom
The fire services in the United Kingdom operate under separate legislative and administrative arrangements in England and Wales, Northern Ireland, Scotland. Emergency cover is provided by over fifty agencies; these are known as a fire and rescue service, the term used in modern legislation and by government departments. The older terms of fire brigade and fire service survive in informal usage and in the names of a few organisations. England and Wales have local fire services which are each overseen by a fire authority, made up of representatives of local governments. Fire authorities have the power to raise a Council Tax levy for funding, with the remainder coming from the government. Scotland and Northern Ireland have centralised fire services, so their authorities are committees of the devolved parliaments; the total budget for fire services in 2014-15 was £2.9 billion. Central government maintains national standards and a body of independent advisers through the Chief Fire and Rescue Adviser, created in 2007, while Her Majesty's Inspectorate of Constabulary and Fire & Rescue Services provides direct oversight.
The devolved government in Scotland has HMFSI Scotland. Firefighters in the United Kingdom are allowed to join unions, the main one being the Fire Brigades Union, while chief fire officers are members of the National Fire Chiefs Council, which has some role in national co-ordination; the fire services have undergone significant changes since the beginning of the 21st century, a process, propelled by a devolution of central government powers, new legislation and a change to operational procedures in the light of terrorism attacks and threats. See separate article History of fire safety legislation in the United Kingdom Comprehensive list of recent UK fire and rescue service legislation: Fire services are established and granted their powers under new legislation which has replaced a number of Acts of Parliament dating back more than 60 years, but is still undergoing change. 1938: Fire Brigades Act 1938. This Act provided for centralised co-ordination of fire brigades in Great Britain and made it mandatory for local authorities to arrange an effective fire service.
1947: Fire Services Act 1947 This Act transferred the functions of the National Fire Service to local authorities. Now repealed in England and Wales by Schedule 2 of the Fire and Rescue Services Act 2004. 1959: Fire Services Act 1959 This Act amended the 1947 Act. It was repealed in Wales along with the 1947 Act. 1999: Greater London Authority Act 1999 This act was necessary to allow for the formation of the Greater London Authority and in turn the London Fire and Emergency Planning Authority. In 2002, there was a series of national fire strikes, with much of the discontent caused by the aforementioned report into the fire service conducted by Prof Sir George Bain. In December 2002, the Independent Review of the Fire Service was published with the industrial action still ongoing. Bain's report led to a change in the laws relating to firefighting. 2002: Independent Review of the Fire Service published 2004: Fire and Rescue Services Act 2004 only applying to England and Wales. 2006: The Regulatory Reform Order 2005 This piece of secondary legislation or statutory instrument replaces several other acts that dealt with fire precautions and fire safety in premises, including the now defunct process of issuing fire certificates.
It came into force on 1 October 2006. The DfCLG has published a set of guides for non-domestic premises: 2006: The Government of Wales Act 2006 gave the National Assembly for Wales powers to pass laws on "Fire and rescue services. Promotion of fire safety otherwise than by prohibition or regulation." But does not prevent future legislation being passed by the UK government which applies to two or more constituent countries. There are further plans to modernise the fire service according to the Local Government Association, its website outlines future changes, specific projects: "The aim of the Fire Modernisation Programme is to adopt modern work practices within the Fire & Rescue Service to become more efficient and effective, while strengthening the contingency and resilience of the Service to react to incidents. " The fire service in England and Wales is scrutinised by a House of Commons select committee. In June 2006, the fire and rescue service select committee, under the auspices of the Communities and Local Government Committee, published its latest report.
Committee report The committee's brief is described on its website: The Communities and Local Government Committee is appointed by the House of Commons to examine the expenditure and policy of the Department for Communities and Local Government and its associated bodies. Government response This document, the subsequent government response in September 2006, are important as they outlined progress on the FiReControl, efforts to address diversity and the planned closure of HMFSI in 2007 among many issues. Both documents are interesting as they refer back to Professor Bain's report and the many recommendations it made and continue to put forward the notion that there is an ongoing need to modernise FRSs. For example, where FRSs were inspected by HMFSI, much of this work is now carried out by the National Audit Office. Fire Control On 8 February 2010 the House of Commons Communities and Local Governm
Limestone is a carbonate sedimentary rock, composed of the skeletal fragments of marine organisms such as coral and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate. A related rock is dolostone, which contains a high percentage of the mineral dolomite, CaMg2. In fact, in old USGS publications, dolostone was referred to as magnesian limestone, a term now reserved for magnesium-deficient dolostones or magnesium-rich limestones. About 10% of sedimentary rocks are limestones; the solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. Limestone has numerous uses: as a building material, an essential component of concrete, as aggregate for the base of roads, as white pigment or filler in products such as toothpaste or paints, as a chemical feedstock for the production of lime, as a soil conditioner, or as a popular decorative addition to rock gardens.
Like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of marine organisms such as foraminifera; these organisms secrete shells made of aragonite or calcite, leave these shells behind when they die. Other carbonate grains composing limestones are ooids, peloids and extraclasts. Limestone contains variable amounts of silica in the form of chert or siliceous skeletal fragment, varying amounts of clay and sand carried in by rivers; some limestones do not consist of grains, are formed by the chemical precipitation of calcite or aragonite, i.e. travertine. Secondary calcite may be deposited by supersaturated meteoric waters; this produces speleothems, such as stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance; the primary source of the calcite in limestone is most marine organisms. Some of these organisms can construct mounds of rock building upon past generations. Below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone does not form in deeper waters.
Limestones may form in lacustrine and evaporite depositional environments. Calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, dissolved ion concentrations. Calcite exhibits an unusual characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors with weathered surfaces. Limestone may be crystalline, granular, or massive, depending on the method of formation. Crystals of calcite, dolomite or barite may line small cavities in the rock; when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams where there are waterfalls and around hot or cold springs. Calcium carbonate is deposited where evaporation of the water leaves a solution supersaturated with the chemical constituents of calcite.
Tufa, a porous or cellular variety of travertine, is found near waterfalls. Coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the mountain building process, limestone recrystallizes into marble. Limestone is a parent material of Mollisol soil group. Two major classification schemes, the Folk and the Dunham, are used for identifying the types of carbonate rocks collectively known as limestone. Robert L. Folk developed a classification system that places primary emphasis on the detailed composition of grains and interstitial material in carbonate rocks. Based on composition, there are three main components: allochems and cement; the Folk system uses two-part names. It is helpful to have a petrographic microscope when using the Folk scheme, because it is easier to determine the components present in each sample; the Dunham scheme focuses on depositional textures. Each name is based upon the texture of the grains. Robert J. Dunham published his system for limestone in 1962.
Dunham divides the rocks into four main groups based on relative proportions of coarser clastic particles. Dunham names are for rock families, his efforts deal with the question of whether or not the grains were in mutual contact, therefore self-supporting, or whether the rock is characterized by the presence of frame builders and algal mats. Unlike the Folk scheme, Dunham deals with the original porosity of the rock; the Dunham scheme is more useful for hand samples because it is based on texture, not the grains in the sample. A revised classification was proposed by Wright, it adds some diagenetic patterns and can be summarized as follows: See: Carbonate platform About 10% of all sedimentary rocks are limestones. Limestone is soluble in acid, therefore forms many erosional landforms; these include limestone pavements, pot holes, cenotes and gorges. Such erosion landscapes are known