Sandstone is a clastic sedimentary rock composed of sand-sized mineral particles or rock fragments. Most sandstone is composed of quartz or feldspar because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in Bowen's reaction series. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, yellow, grey, pink and black. Since sandstone beds form visible cliffs and other topographic features, certain colors of sandstone have been identified with certain regions. Rock formations that are composed of sandstone allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity. Quartz-bearing sandstone can be changed into quartzite through metamorphism related to tectonic compression within orogenic belts.
Sandstones are clastic in origin. They are formed from cemented grains that may either be fragments of a pre-existing rock or be mono-minerallic crystals; the cements binding these grains together are calcite and silica. Grain sizes in sands are defined within the range of 0.0625 mm to 2 mm. Clays and sediments with smaller grain sizes not visible with the naked eye, including siltstones and shales, are called argillaceous sediments; the formation of sandstone involves two principal stages. First, a layer or layers of sand accumulates as the result of sedimentation, either from water or from air. Sedimentation occurs by the sand settling out from suspension. Once it has accumulated, the sand becomes sandstone when it is compacted by the pressure of overlying deposits and cemented by the precipitation of minerals within the pore spaces between sand grains; the most common cementing materials are silica and calcium carbonate, which are derived either from dissolution or from alteration of the sand after it was buried.
Colors will be tan or yellow. A predominant additional colourant in the southwestern United States is iron oxide, which imparts reddish tints ranging from pink to dark red, with additional manganese imparting a purplish hue. Red sandstones are seen in the Southwest and West of Britain, as well as central Europe and Mongolia; the regularity of the latter favours use as a source for masonry, either as a primary building material or as a facing stone, over other forms of construction. The environment where it is deposited is crucial in determining the characteristics of the resulting sandstone, which, in finer detail, include its grain size and composition and, in more general detail, include the rock geometry and sedimentary structures. Principal environments of deposition may be split between terrestrial and marine, as illustrated by the following broad groupings: Terrestrial environmentsRivers Alluvial fans Glacial outwash Lakes Deserts Marine environmentsDeltas Beach and shoreface sands Tidal flats Offshore bars and sand waves Storm deposits Turbidites Framework grains are sand-sized detrital fragments that make up the bulk of a sandstone.
These grains can be classified into several different categories based on their mineral composition: Quartz framework grains are the dominant minerals in most clastic sedimentary rocks. These physical properties allow the quartz grains to survive multiple recycling events, while allowing the grains to display some degree of rounding. Quartz grains evolve from plutonic rock, which are felsic in origin and from older sandstones that have been recycled. Feldspathic framework grains are the second most abundant mineral in sandstones. Feldspar can be divided into two smaller subdivisions: plagioclase feldspars; the different types of feldspar can be distinguished under a petrographic microscope. Below is a description of the different types of feldspar. Alkali feldspar is a group of minerals in which the chemical composition of the mineral can range from KAlSi3O8 to NaAlSi3O8, this represents a complete solid solution. Plagioclase feldspar is a complex group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8.
Lithic framework grains are pieces of ancient source rock that have yet to weather away to individual mineral grains, called lithic fragments or clasts. Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock, although the most common lithic fragments found in sedimentary rocks are clasts of volcanic rocks. Accessory minerals are all other mineral grains in a sandstone. Common accessory minerals include micas, olivine and corundum. Many of these accessory grains are more dense than the silicates that
A towpath is a road or trail on the bank of a river, canal, or other inland waterway. The purpose of a towpath is to allow a land vehicle, beasts of burden, or a team of human pullers to tow a boat a barge; this mode of transport was common where sailing was impractical due to tunnels and bridges, unfavourable winds, or the narrowness of the channel. After the Industrial Revolution, towing became obsolete when engines were fitted on boats and when railway transportation superseded the slow towing method. Since many of these towpaths have been converted to multi-use trails, they are still named towpaths — although they are now only used for the purpose of towing boats. Early inland waterway transport used the rivers, while barges could use sails to assist their passage when winds were favourable or the river was wide enough to allow tacking, in many cases this was not possible, gangs of men were used to bow-haul the boats; as river banks were privately owned, such teams worked their way along the river banks as best they could, but this was far from satisfactory.
On British rivers such as the River Severn, the situation was improved by the creation of towing path companies in the late 1700s. The companies built towing paths along the banks of the river, four such companies improved a section of 24 miles in this way between Bewdley and Coalbrookdale, they were not universally popular, however, as tolls were charged for their use, to recoup the capital cost, this was resented on rivers where barge traffic had been free. With the advent of artificial canals, most of them were constructed with towpaths suitable for horses. Many rivers were improved by artificial cuts, this gave an opportunity to construct a towing path at the same time. So, the River Don Navigation was improved from Tinsley to Rotherham in 1751, but the horse towing path was not completed on this section until 1822. On the River Avon between Stratford-upon-Avon and Tewkesbury, a towpath was never provided, bow-hauling continued until the 1860s, when steam tugs were introduced. While towing paths were most convenient when they stayed on one side of a canal, there were occasions where it had to change sides because of opposition from landowners.
Thus the towpath on the Chesterfield Canal changes to the south bank while it passes through the Osberton Estate, as the Foljambes, who lived in Osberton Hall, did not want boatmen passing too close to their residence. On canals, one solution to the problem of getting the horse to the other side was the roving bridge or turnover bridge, where the horse ascended the ramp on one side, crossed the bridge, descended a circular ramp on the other side of the river but the same side of the bridge, passed through the bridge hole to continue on its way; this had the benefit. Where the towpath reached a lock, spanned by a footbridge at its tail, the southern section of the Stratford-on-Avon Canal used split bridges so that the horse line did not have to be detached; the rope passed through a small gap at the centre of the bridge between its two halves. One problem with the horse towing path where it passed under a bridge was abrasion of the rope on the bridge arch; this resulted in deep grooves being cut in the fabric of the bridge, in many cases, the structure was protected by cast iron plates, attached to the faces of the arch.
These too soon developed deep grooves, but could be more replaced than the stonework of the bridge. While bridges could be constructed over narrow canals, they were more costly on wide navigable rivers, in many cases horse ferries were provided, to enable the horse to reach the next stretch of towpath. In more recent times, this has provided difficulties for walkers, where an attractive river-side walk cannot be followed because the towpath changes sides and the ferry is no more. Not all haulage was by horses, an experiment was carried out on the Middlewich Branch of the Shropshire Union Canal in 1888. Following suggestions by Francis W. Webb, the Mechanical Engineer for the London and North Western Railway at Crewe Works, rails were laid along a 1-mile stretch of the towpath near Worleston, a small steam locomotive borrowed from Crewe Works was used to tow boats; the locomotive ran on 18 in gauge tracks, was similar to Pet, preserved in the National Railway Museum at York. It pulled trains of two and four boats at 7 mph, experiments were tried with eight boats.
The canal's engineer, G. R. Webb, produced a report on the expected costs of laying rails along the towpaths, but nothing more was heard of the project, the advent of steam and diesel powered boats offered a much simpler solution. The'mules' which assist ships through the locks of the Panama Canal are a modern example of the concept. Towpaths are popular with cyclists and walkers, some are suitable for equestrians. In snowy winters they are popular in the USA with snowmobile users. Although not designed or used as towpaths, acequia ditch banks are popular recreational trails. In Britain, most canals were built and operated by private companies, the towpaths were deemed to be private, for the benefit of legitimate users of the canal; the nationalisation of the canal system in 1948 did not result in the towpaths becoming public rights of way. Subsequent legislation, such as the Transport Act 1968, which defined the government's obligations to the maintenance of the inland waterways for which it was now responsible, did not include any commitment to maintain towpaths for use by anyone, some ten years British Waterways started to relax the rule that a permit was required to give a
Bas-Rhin is a department in Alsace, a part of the Grand Est super-region of France. The name means "Lower Rhine", geographically speaking it belongs to the Upper Rhine region, it is the more populous and densely populated of the two departments of the traditional Alsace region, with 1,121,407 inhabitants in 2016. The prefecture and the General Council are based in Strasbourg; the INSEE and Post Code is 67. The inhabitants of the department are known as Bas-Rhinoises; the Rhine has always been of great historical and economic importance to the area, it forms the eastern border of Bas-Rhin. The area is home to some of the foothills of the Vosges Mountains. To the north of Bas-Rhin lies the Palatinate forest in the German State of Rhineland-Palatinate, the German State of Baden-Württemberg lies to the east. To the south lies the department of Haut-Rhin, the town of Colmar and southern Alsace, to the west the department of Moselle. On its south-western corner, Bas-Rhin joins the department of Vosges.
The Bas-Rhin has a continental-type climate, characterised by cold, dry winters and hot, stormy summers, due to the western protection provided by the Vosges. The average annual temperature is 7 °C on high ground; the annual maximum temperature is high. The average rainfall is 700 mm per year. Established according to data from the Infoclimat station at Strasbourg-Entzheim, over the period from 1961 to 1990; this is the last French department to have kept the term Bas meaning "Lower" in its name. Other departments using this prefix preferred to change their names - e.g.: Basses-Pyrenees in 1969 became Pyrénées-Atlantiques and Basses-Alpes in 1970 became the department of Alpes-de-Haute-Provence. The same phenomenon was observed for the inférieur departments such as Charente-Inférieure, Seine-Inférieure, Loire-Inférieure. Bas-Rhin is one of the original 83 departments created on 4 March 1790, during the French Revolution. On 14 January 1790 the National Constituent Assembly decreed: "- That Alsace be divided into two departments with Strasbourg and Colmar as their capitals.
In 1871 Bas-Rhin was annexed by Germany and became Bezirk Unterelsass in Reichsland Elsaß-Lothringen. Strasbourg, the chef lieu of Bas-Rhin is the official seat of the European Parliament as well as of the Council of Europe; the demography of Bas-Rhin is characterized by high density and high population growth since the 1950s. In January 2014 Bas-Rhin had 1,112,815 inhabitants and was 18th by population at the national level. In fifteen years, from 1999 to 2014, its population grew by more than 86,000 people, or about 5,800 people per year, but this variation is differentiated among the 517 communes. The population density of Bas-Rhin is 234 inhabitants per square kilometre in 2014, more than twice the average in France, 112 in 2009; the first census was conducted in 1801 and this count, renewed every five years from 1821, provides precise information on the evolution of population in the department. With 540,213 inhabitants in 1831, the department represented 1.66% of the total French population, 32,569,000 inhabitants.
From 1831 to 1866, the department gained 48,757 people, an increase of 0.26% on average per year compared to the national average of 0.48% over the same period. Demographic change between the Franco-Prussian War of 1870 and the First World War was higher than the national average. Over this period, the population increased by 100,532 inhabitants, an increase of 16.74%, compared to 10% nationally. The population increased by 9.23% between the two world wars from 1921 to 1936 compared to a national growth of 6.9%. Like other French departments, Bas-Rhin experienced a population boom after the Second World War, higher than the national level; the rate of population growth between 1946 and 2007 was 83.83%
The Bruche is a river in Alsace, in north-eastern France. It is a left-side tributary of the Ill, part of the Rhine basin, it is 76.7 km long, has a drainage basin of 720 km². Its source is in the Vosges, at the western foot of the mountain Climont, near the village of Bourg-Bruche, it flows through the towns Schirmeck, Mutzig and Holtzheim. It flows into the Ill in the city of southwest of the historic centre, its largest tributary is the river Mossig. At Wolxheim, where the Bruche and Mossig meet, part of the water feeds the Canal de la Bruche, built in 1682 to link the sandstone quarries at Soultz-les-Bains with Strasbourg; the canal remained in use until 1939
Strasbourg is the capital and largest city of the Grand Est region of France and is the official seat of the European Parliament. Located at the border with Germany in the historic region of Alsace, it is the capital of the Bas-Rhin department. In 2016, the city proper had 279,284 inhabitants and both the Eurométropole de Strasbourg and the Arrondissement of Strasbourg had 491,409 inhabitants. Strasbourg's metropolitan area had a population of 785,839 in 2015, making it the ninth largest metro area in France and home to 13% of the Grand Est region's inhabitants; the transnational Eurodistrict Strasbourg-Ortenau had a population of 915,000 inhabitants in 2014. Strasbourg is one of the de facto capitals of the European Union, as it is the seat of several European institutions, such as the Council of Europe and the Eurocorps, as well as the European Parliament and the European Ombudsman of the European Union; the city is the seat of the Central Commission for Navigation on the Rhine and the International Institute of Human Rights.
Strasbourg's historic city centre, the Grande Île, was classified a World Heritage Site by UNESCO in 1988, the first time such an honour was placed on an entire city centre. Strasbourg is immersed in Franco-German culture and although violently disputed throughout history, has been a cultural bridge between France and Germany for centuries through the University of Strasbourg the second largest in France, the coexistence of Catholic and Protestant culture, it is home to the largest Islamic place of worship in France, the Strasbourg Grand Mosque. Economically, Strasbourg is an important centre of manufacturing and engineering, as well as a hub of road and river transportation; the port of Strasbourg is the second largest on the Rhine after Germany. Before the 5th century, the city was known as Argantorati, a Celtic Gaulish name Latinized first as Argentorate, as Argentoratum; that Gaulish name is a compound of -rati, the Gaulish word for fortified enclosures, cognate to the Old Irish ráth, arganto-, the Gaulish word for silver, but any precious metal gold, suggesting either a fortified enclosure located by a river gold mining site, or hoarding gold mined in the nearby rivers.
After the 5th century, the city became known by a different name Gallicized as Strasbourg. That name is of Germanic origin and means "Town of roads"; the modern Stras- is cognate to the German Straße and English street, all of which are derived from Latin strata, while -bourg is cognate to the German Burg and English borough, all of which are derived from Proto-Germanic *burgz. Gregory of Tours was the first to mention the name change: in the tenth book of his History of the Franks written shortly after 590 he said that Egidius, Bishop of Reims, accused of plotting against King Childebert II of Austrasia in favor of his uncle King Chilperic I of Neustria, was tried by a synod of Austrasian bishops in Metz in November 590, found guilty and removed from the priesthood taken "ad Argentoratensem urbem, quam nunc Strateburgum vocant", where he was exiled. Strasbourg is situated at the eastern border of France with Germany; this border is formed by the Rhine, which forms the eastern border of the modern city, facing across the river to the German town Kehl.
The historic core of Strasbourg however lies on the Grande Île in the river Ill, which here flows parallel to, 4 kilometres from, the Rhine. The natural courses of the two rivers join some distance downstream of Strasbourg, although several artificial waterways now connect them within the city; the city lies in the Upper Rhine Plain, at between 132 metres and 151 metres above sea level, with the upland areas of the Vosges Mountains some 20 km to the west and the Black Forest 25 km to the east. This section of the Rhine valley is a major axis of north–south travel, with river traffic on the Rhine itself, major roads and railways paralleling it on both banks; the city is some 397 kilometres east of Paris. The mouth of the Rhine lies 450 kilometres to the north, or 650 kilometres as the river flows, whilst the head of navigation in Basel is some 100 kilometres to the south, or 150 kilometres by river. In spite of its position far inland, Strasbourg's climate is classified as oceanic, but a "semicontinental" climate with some degree of maritime influence in relation to the mild patterns of Western and Southern France.
The city has warm sunny summers and cool, overcast winters. Precipitation is elevated from mid-spring to the end of summer, but remains constant throughout the year, totaling 631.4 mm annually. On average, snow falls 30 days per year; the highest temperature recorded was 38.5 °C in August 2003, during the 2003 European heat wave. The lowest temperature eve
Template:Expand Alemannisch The Canal du Rhône au Rhin is one of the important watershed canals of the French waterways, connecting the Rhine to the Saône and the Rhône and thereby the North Sea and the Mediterranean. As built, the canal was made up of four distinct sections: the branche Sud or southern branch, 224 km from the Saône just north of Saint-Jean-de-Losne to the Île Napoléon basin and junction just east of Mulhouse, the branche Nord or northern branch, 134 km from the Mulhouse junction to the Dusuzeau basin in the port of Strasbourg, the 22-km-long Canal de Huningue, from the junction to the Rhine at Huningue, just north from the Swiss port of Basle, the 10-km-long Belfort branch, which when built was to be the first section of the Canal de Montbéliard à la Haute-Saône. Developments for high-capacity navigation in the second half of the 20th century transformed this Y-shaped system; when the first lock was built on the Grand Canal d'Alsace at Kembs, a new cut was excavated from Kembs to Niffer, the rest of the Canal de Huningue was upgraded from here to the docks at Mulhouse.
A 3-km-long section of the former Canal de Huningue, from Niffer to Kembs, is maintained and gives access to a boat harbour, while the remainder of that canal to Basel has been closed, the terminal basin transformed into a whitewater canoeing course. Most of the northern branch was abandoned, in the early 1980s the A36 motorway sliced through the canal embankment east of Mulhouse. Two sections were maintained and new cuts built from the Rhine to make them accessible: the Colmar Canal or embranchement de Colmar 23 km long, from a new lock at Neuf-Brisach to Colmar, a 34 km lateral canal starting from a new entrance lock at Rhinau and finishing in the basins of the port of Strasbourg. A further major upheaval, planned from the 1960s, was construction of a high-capacity waterway to connect the Rhône-Saône corridor with the main European waterway network; this project was abandoned by Environment Minister Dominique Voynet in 1997. The section from Mulhouse to Neuf-Brisach is abandoned, while the 29 km section between Artzenheim and Friesenheim has been restored by Alsace Region, but works were stopped in 2009 for financial reasons.
A cycle path was built along this section in 2011, extending the popular cycle path south from Strasbourg. The first section of the Canal de Franche-Comté was authorised by Burgundy Council in 1783 and completed in 1802 from the Saône to Dôle. Napoleon was seeking to develop inland waterway connections throughout the country, the Rhône-Rhine link was of such strategic importance that he gave his name to the project; the Emperor’s administration conceived the predecessor of today’s public-private partnership model, selling existing canals to private companies, to provide funds for new links. The proceeds were diverted for the war effort, it was not until 1821 that this project, now renamed ‘Canal Monsieur’, was reactivated by the canal company set up for this purpose. Works were completed in 1833. Upgrading to Freycinet standards started in 1882, the summit level was lowered, reducing the number of locks; the new high-capacity Rhine-Rhône waterway would have made the canal obsolete, but the environment minister Dominique Voynet cancelled that project in 1997.
The Government funded – as compensation – the backlog of maintenance works and other improvements, but with little impact on commercial traffic in 250-tonne péniches, which has all but disappeared. List of canals in France Hutchinson Encyclopedia Waterways in France on Discover France! Canal du Rhône au Rhin, waterways guide No. 9, Editions du Breil, texts in French and German Canal du Rhône au Rhin with information on places and moorings on the canal, by the author of Inland Waterways of France, Imray River Ill and Canal du Rhône au Rhin with information on places and moorings on the canal, by the author of Inland Waterways of France, Imray Navigation details for 80 French rivers and canals
London is the capital and largest city of both England and the United Kingdom. Standing on the River Thames in the south-east of England, at the head of its 50-mile estuary leading to the North Sea, London has been a major settlement for two millennia. Londinium was founded by the Romans; the City of London, London's ancient core − an area of just 1.12 square miles and colloquially known as the Square Mile − retains boundaries that follow its medieval limits. The City of Westminster is an Inner London borough holding city status. Greater London is governed by the Mayor of the London Assembly. London is considered to be one of the world's most important global cities and has been termed the world's most powerful, most desirable, most influential, most visited, most expensive, sustainable, most investment friendly, most popular for work, the most vegetarian friendly city in the world. London exerts a considerable impact upon the arts, education, fashion, healthcare, professional services and development, tourism and transportation.
London ranks 26 out of 300 major cities for economic performance. It is one of the largest financial centres and has either the fifth or sixth largest metropolitan area GDP, it is the most-visited city as measured by international arrivals and has the busiest city airport system as measured by passenger traffic. It is the leading investment destination, hosting more international retailers and ultra high-net-worth individuals than any other city. London's universities form the largest concentration of higher education institutes in Europe. In 2012, London became the first city to have hosted three modern Summer Olympic Games. London has a diverse range of people and cultures, more than 300 languages are spoken in the region, its estimated mid-2016 municipal population was 8,787,892, the most populous of any city in the European Union and accounting for 13.4% of the UK population. London's urban area is the second most populous in the EU, after Paris, with 9,787,426 inhabitants at the 2011 census.
The population within the London commuter belt is the most populous in the EU with 14,040,163 inhabitants in 2016. London was the world's most populous city from c. 1831 to 1925. London contains four World Heritage Sites: the Tower of London. Other landmarks include Buckingham Palace, the London Eye, Piccadilly Circus, St Paul's Cathedral, Tower Bridge, Trafalgar Square and The Shard. London has numerous museums, galleries and sporting events; these include the British Museum, National Gallery, Natural History Museum, Tate Modern, British Library and West End theatres. The London Underground is the oldest underground railway network in the world. "London" is an ancient name, attested in the first century AD in the Latinised form Londinium. Over the years, the name has attracted many mythicising explanations; the earliest attested appears in Geoffrey of Monmouth's Historia Regum Britanniae, written around 1136. This had it that the name originated from a supposed King Lud, who had taken over the city and named it Kaerlud.
Modern scientific analyses of the name must account for the origins of the different forms found in early sources Latin, Old English, Welsh, with reference to the known developments over time of sounds in those different languages. It is agreed; this was adapted into Latin as Londinium and borrowed into Old English, the ancestor-language of English. The toponymy of the Common Brythonic form is much debated. A prominent explanation was Richard Coates's 1998 argument that the name derived from pre-Celtic Old European *lowonida, meaning "river too wide to ford". Coates suggested that this was a name given to the part of the River Thames which flows through London. However, most work has accepted a Celtic origin for the name, recent studies have favoured an explanation along the lines of a Celtic derivative of a proto-Indo-European root *lendh-, combined with the Celtic suffix *-injo- or *-onjo-. Peter Schrijver has suggested, on these grounds, that the name meant'place that floods'; until 1889, the name "London" applied to the City of London, but since it has referred to the County of London and Greater London.
"London" is sometimes written informally as "LDN". In 1993, the remains of a Bronze Age bridge were found on the south foreshore, upstream of Vauxhall Bridge; this bridge either reached a now lost island in it. Two of those timbers were radiocarbon dated to between 1750 BC and 1285 BC. In 2010 the foundations of a large timber structure, dated to between 4800 BC and 4500 BC, were found on the Thames's south foreshore, downstream of Vauxhall Bridge; the function of the mesolithic structure is not known. Both structures are on the south bank. Although there is evidence of scattered Brythonic settlements in the area, the first major settlement was founded by the Romans about four years after the invasion