Misplaced Pages

#789210

105-575: Cherbourg is protected by Cherbourg Harbour , between La Hague and Val de Saire , and the city has been a strategic position over the centuries, disputed between the English and French. Cited as one of the "keys to the kingdom" by Vauban , it became, by colossal maritime development work, a first-rate military port under the leadership of Napoleon I , and holds an arsenal of the French Navy . A stopping point for prestigious transatlantic liners in

210-521: A Croix de guerre 1939-1945 with natural palm, appended at the point of the shield and surmounting the croisure strips. The origin of the coat of arms is disputed. According to Victor Le Sens, it is of religious origin: Fess argent charged of stars represents the belt of the Virgin Mary , one of the two patrons of the city and the number of stars, like the bezants , evokes the Trinity ,

315-563: A basaltic magma to a granitic magma, but the quantities produced are small. For example, granitic rock makes up just 4% of the exposures in the South Sandwich Islands . In continental arc settings, granitic rocks are the most common plutonic rocks, and batholiths composed of these rock types extend the entire length of the arc. There are no indication of magma chambers where basaltic magmas differentiate into granites, or of cumulates produced by mafic crystals settling out of

420-520: A diapir it would expend far too much energy in heating wall rocks, thus cooling and solidifying before reaching higher levels within the crust. Fracture propagation is the mechanism preferred by many geologists as it largely eliminates the major problems of moving a huge mass of magma through cold brittle crust. Magma rises instead in small channels along self-propagating dykes which form along new or pre-existing fracture or fault systems and networks of active shear zones. As these narrow conduits open,

525-610: A granite that is derived from partial melting of metasedimentary rocks may have more alkali feldspar, whereas a granite derived from partial melting of metaigneous rocks may be richer in plagioclase. It is on this basis that the modern "alphabet" classification schemes are based. The letter-based Chappell & White classification system was proposed initially to divide granites into I-type (igneous source) granite and S-type (sedimentary sources). Both types are produced by partial melting of crustal rocks, either metaigneous rocks or metasedimentary rocks. I-type granites are characterized by

630-552: A great commercial port, it is nonetheless an important shipbuilding centre, and a working-class city with a rural hinterland. Cherbourg is located at the northern tip of the Cotentin Peninsula , in the department of Manche , of which it is a subprefecture . At the time of the 1999 census the city of Cherbourg had an area of 6.91 square kilometres (2.668 sq mi), while the city of Octeville had an area of 7.35 km (2.838 sq mi). The largest city in

735-422: A gull, symbolising the maritime character of the town, on a musical stave, evoking the musicality of the port: "The cry of the seagulls that dance between sky and sea, the mermaids of ships and the melodious song of the waves". The date of Foundation of Cherbourg can not be set precisely, although several local historians, including Robert Lerouvillois, trace the origin of the city to Coriallo (for * Coriovallo ) of

840-512: A high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions . These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of granitic rocks , or granitoids , that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by

945-565: A high content of sodium and calcium, and by a strontium isotope ratio, Sr/ Sr, of less than 0.708. Sr is produced by radioactive decay of Rb, and since rubidium is concentrated in the crust relative to the mantle, a low ratio suggests origin in the mantle. The elevated sodium and calcium favor crystallization of hornblende rather than biotite. I-type granites are known for their porphyry copper deposits. I-type granites are orogenic (associated with mountain building) and usually metaluminous. S-type granites are sodium-poor and aluminum-rich. As

1050-695: A million passengers every year. This line continued, at the beginning of the 20th century, up to the resort of Urville-Nacqueville and was complemented by the Tue-Vâques  [ fr ] which served from Cherbourg to Val de Saire between 1911 and 1950. Today, the Intercités Paris-Caen-Cherbourg line is the most profitable in its class with profit over €10 million per year despite numerous incidents and delays. Regular services operate to Paris-Saint-Lazare via Caen using Intercités stock, local TER services operate from

1155-824: A much higher proportion of clay with the Cecil soil series a prime example of the consequent Ultisol great soil group. Granite is a natural source of radiation , like most natural stones. Potassium-40 is a radioactive isotope of weak emission, and a constituent of alkali feldspar , which in turn is a common component of granitic rocks, more abundant in alkali feldspar granite and syenites . Some granites contain around 10 to 20 parts per million (ppm) of uranium . By contrast, more mafic rocks, such as tonalite, gabbro and diorite , have 1 to 5 ppm uranium, and limestones and sedimentary rocks usually have equally low amounts. Many large granite plutons are sources for palaeochannel -hosted or roll front uranium ore deposits , where

SECTION 10

#1732765879790

1260-637: A night bus service has also been created. Cherbourg-Octeville and its suburbs are also served by the Manéo departmental bus service. The Cherbourg – Maupertus Airport , located in Maupertus-sur-Mer , serves the city. Its 2,440 m (8,010 ft) runway hosts charter flights . After stopping the daily service to Paris by Twin Jet , in spring 2008, a new link with Caen and Paris started with Chalair on 27 October 2008. With 40,500 passengers in 2007,

1365-536: A peculiar mineralogy and geochemistry, with particularly high silicon and potassium at the expense of calcium and magnesium and a high content of high field strength cations (cations with a small radius and high electrical charge, such as zirconium , niobium , tantalum , and rare earth elements .) They are not orogenic, forming instead over hot spots and continental rifting, and are metaluminous to mildly peralkaline and iron-rich. These granites are produced by partial melting of refractory lithology such as granulites in

1470-568: A range of hills, formed by the metamorphic aureole or hornfels . Granite often occurs as relatively small, less than 100 km stock masses ( stocks ) and in batholiths that are often associated with orogenic mountain ranges. Small dikes of granitic composition called aplites are often associated with the margins of granitic intrusions . In some locations, very coarse-grained pegmatite masses occur with granite. Granite forms from silica-rich ( felsic ) magmas. Felsic magmas are thought to form by addition of heat or water vapor to rock of

1575-565: A rapid change of weather in a single day, with sun and rain which can be a few hours apart. The influence of the Gulf Stream and the mildness of the winter allow the naturalisation of many Mediterranean and exotic plants ( mimosas , palms , agaves , etc.) which are present in the public and private gardens of the city, despite average insolation. The climate is similar to areas much further north in Great Britain and Ireland due to

1680-415: A result, they contain micas such as biotite and muscovite instead of hornblende. Their strontium isotope ratio is typically greater than 0.708, suggesting a crustal origin. They also commonly contain xenoliths of metamorphosed sedimentary rock, and host tin ores. Their magmas are water-rich, and they readily solidify as the water outgasses from the magma at lower pressure, so they less commonly make it to

1785-487: A surface area of 1,500 hectares, it is the second largest artificial harbour in the world, after the 4,500 hectare Ras Laffan Harbour in Qatar. As well as Cherbourg Naval Base , it has been used for mercantile shipping. It was begun in 1783, with its central harbour breakwater completed in 1853 – this was 3.64 km long, an average of 100 m wide at its base and an average of 12 m wide at its top, and sited 4 km from

1890-466: Is grus , which is often made up of coarse-grained fragments of disintegrated granite. Climatic variations also influence the weathering rate of granites. For about two thousand years, the relief engravings on Cleopatra's Needle obelisk had survived the arid conditions of its origin before its transfer to London. Within two hundred years, the red granite has drastically deteriorated in the damp and polluted air there. Soil development on granite reflects

1995-545: Is microgranite . The extrusive igneous rock equivalent of granite is rhyolite . Granitic rock is widely distributed throughout the continental crust . Much of it was intruded during the Precambrian age; it is the most abundant basement rock that underlies the relatively thin sedimentary veneer of the continents. Outcrops of granite tend to form tors , domes or bornhardts , and rounded massifs . Granites sometimes occur in circular depressions surrounded by

2100-517: Is 3–6·10 Pa·s. The melting temperature of dry granite at ambient pressure is 1215–1260 °C (2219–2300 °F); it is strongly reduced in the presence of water, down to 650 °C at a few hundred megapascals of pressure. Granite has poor primary permeability overall, but strong secondary permeability through cracks and fractures if they are present. A worldwide average of the chemical composition of granite, by weight percent, based on 2485 analyses: The medium-grained equivalent of granite

2205-450: Is a former rural municipality, composed of hamlets, whose settlement extended from the 19th century and whose territory is highly urbanised since 1950, especially around the ZUP  [ fr ] of the provinces and the university campus. The bordering communes are Tourlaville to the east, Équeurdreville-Hainneville to the west, La Glacerie to the south and southeast, Martinvast to

SECTION 20

#1732765879790

2310-403: Is also the name of a Canadian township , located between Matane and Les Méchins , which gave its name to the communes of Saint-Thomas-de-Cherbourg, merged in 1954 into Les Méchins, and Saint-Jean-de-Cherbourg . This name, including the proclamation date of 7 May 1864, could be due to the impact by the local newspapers of the inauguration of the military port by Napoleon III in 1858. Cherbourg

2415-661: Is also the name of a town in Queensland , Australia. The Cotentin, conquered by Quintus Titurius Sabinus in 56 BC, was divided between the pagus constantiensis ("County of Coutances") and the pagus coriovallensis ("County of Coriallo"), within Gallia Lugdunensis . Coriallo housed a small garrison and a castrum was built on the left bank of the Divette as an element of the Litus saxonicum , after Saxon raids at

2520-410: Is an excess of aluminum beyond what can be taken up in feldspars (Al 2 O 3 > CaO + K 2 O + Na 2 O) are described as peraluminous , and they contain aluminum-rich minerals such as muscovite . The average density of granite is between 2.65 and 2.75 g/cm (165 and 172 lb/cu ft), its compressive strength usually lies above 200 MPa (29,000 psi), and its viscosity near STP

2625-637: Is believed to have a mass of around 81 tonnes. It was the tallest temple in south India. Imperial Roman granite was quarried mainly in Egypt, and also in Turkey, and on the islands of Elba and Giglio . Granite became "an integral part of the Roman language of monumental architecture". The quarrying ceased around the third century AD. Beginning in Late Antiquity the granite was reused, which since at least

2730-434: Is called a binary or two-mica granite. Two-mica granites are typically high in potassium and low in plagioclase, and are usually S-type granites or A-type granites, as described below . Another aspect of granite classification is the ratios of metals that potentially form feldspars. Most granites have a composition such that almost all their aluminum and alkali metals (sodium and potassium) are combined as feldspar. This

2835-433: Is limited by the amount of thermal energy available, which must be replenished by crystallization of higher-melting minerals in the magma. Thus, the magma is melting crustal rock at its roof while simultaneously crystallizing at its base. This results in steady contamination with crustal material as the magma rises. This may not be evident in the major and minor element chemistry, since the minerals most likely to crystallize at

2940-404: Is permeated by sheets and channels of light granitic rock (the leucosome ). The leucosome is interpreted as partial melt of a parent rock that has begun to separate from the remaining solid residue (the melanosome). If enough partial melt is produced, it will separate from the source rock, become more highly evolved through fractional crystallization during its ascent toward the surface, and become

3045-454: Is relieved when overlying material is removed by erosion or other processes. Chemical weathering of granite occurs when dilute carbonic acid , and other acids present in rain and soil waters, alter feldspar in a process called hydrolysis . As demonstrated in the following reaction, this causes potassium feldspar to form kaolinite , with potassium ions, bicarbonate, and silica in solution as byproducts. An end product of granite weathering

3150-411: Is some concern that some granite sold as countertops or building material may be hazardous to health. Dan Steck of St. Johns University has stated that approximately 5% of all granite is of concern, with the caveat that only a tiny percentage of the tens of thousands of granite slab types have been tested. Resources from national geological survey organizations are accessible online to assist in assessing

3255-479: Is that magma will rise through the crust as a single mass through buoyancy . As it rises, it heats the wall rocks , causing them to behave as a power-law fluid and thus flow around the intrusion allowing it to pass without major heat loss. This is entirely feasible in the warm, ductile lower crust where rocks are easily deformed, but runs into problems in the upper crust which is far colder and more brittle. Rocks there do not deform so easily: for magma to rise as

Cherbourg - Misplaced Pages Continue

3360-410: Is the case when K 2 O + Na 2 O + CaO > Al 2 O 3 > K 2 O + Na 2 O. Such granites are described as normal or metaluminous . Granites in which there is not enough aluminum to combine with all the alkali oxides as feldspar (Al 2 O 3 < K 2 O + Na 2 O) are described as peralkaline , and they contain unusual sodium amphiboles such as riebeckite . Granites in which there

3465-459: Is typically orthoclase or microcline and is often perthitic . The plagioclase is typically sodium-rich oligoclase . Phenocrysts are usually alkali feldspar. Granitic rocks are classified according to the QAPF diagram for coarse grained plutonic rocks and are named according to the percentage of quartz , alkali feldspar ( orthoclase , sanidine , or microcline ) and plagioclase feldspar on

3570-428: Is uncommon, is classified simply as quartz-rich granitoid or, if composed almost entirely of quartz, as quartzolite . True granites are further classified by the percentage of their total feldspar that is alkali feldspar. Granites whose feldspar is 65% to 90% alkali feldspar are syenogranites , while the feldspar in monzogranite is 35% to 65% alkali feldspar. A granite containing both muscovite and biotite micas

3675-813: The Cité de la Mer . Frequently, cruise ships that have planned for another destination have taken refuge in the port, for protection from the frequent storms. Conventional cargo ships berth in the eastern area of the docks on the Quai des Flamands and Quai des Mielles . During the construction of the Concorde prototypes in the 1960s, some sections built in the United Kingdom passed by ferry through Cherbourg, for transfer to Toulouse. The Paris - Cherbourg railway line , operated by Réseau Ferré de France , ends at Cherbourg railway station , which opened in 1858 and welcomes

3780-511: The Cotentin . In the 17th century Vauban , Marshal of France , launched a project to fortify the town, but they were finally razed shortly afterwards. In 1692 several naval ships under Amiral de Tourville put into the port at Cherbourg after the opening battle of the Battles of Barfleur and La Hougue —the port's lack of adequate defences were revealed when fire ships destroyed many of

3885-473: The English Channel - this was headed by Suffren and also including Dumouriez (later governor of Cherbourg) and La Bretonnière . La Bretonnière's report considered that only Cherbourg had a harbour large enough for 80 warships at once. Exceeding Vauban's designs, he planned the construction of a 4 km long harbour wall between île Pelée and pointe de Querqueville . Dumouriez and Decaux, head of

3990-576: The French Revolution imminent. This marked a return to La Bretonnière's plan, but in the period between 1789 and 1790 Dumouriez and Cessart left Cherbourg. Subsidies for the project were cut in 1790 and La Bretonnière was forced to hand in his resignation in 1792. Despite a law passed on 1 August 1792 ordering the construction of the military outer port, all works were suspended from 1792 to 1802. In 1802, intending to make Cherbourg one of his main military ports in preparation for his invasion of

4095-758: The Unelli . According to Pierre-Yves Lambert , the Celtic element corio- means "army, troop" and the element vallo- similar to the Latin vallum , would be "rampart, fortification". Mentioned on the Tabula Peutingeriana (c. 365), in the Antonine Itinerary and the Gesta de Fontenelle ("In pago Coriovallinse", 747-753), Coriallo , Latinised then as Coriallum , hosted a Roman garrison during

4200-587: The harbour wall , are now closed. Cherbourg is bordered by the sea. The construction of the port of trade, from 1769, accompanied by the diversion of the Divette  [ fr ] (the mouth of which was located at the current exit of Port Chantereyne) and the Trottebec (from the territory of Tourlaville) gathered in the canal de retenue , along the Avenue de Paris and Rue du Val-de-Saire . The streams of

4305-571: The A-Q-P half of the diagram. True granite (according to modern petrologic convention) contains between 20% and 60% quartz by volume, with 35% to 90% of the total feldspar consisting of alkali feldspar . Granitic rocks poorer in quartz are classified as syenites or monzonites , while granitic rocks dominated by plagioclase are classified as granodiorites or tonalites . Granitic rocks with over 90% alkali feldspar are classified as alkali feldspar granites . Granitic rock with more than 60% quartz, which

Cherbourg - Misplaced Pages Continue

4410-571: The Bucaille and the Fay, which watered the Croûte du Homet , disappeared in the 18th century during the construction of the military port. Cherbourg has a temperate oceanic climate . Its maritime character causes high humidity (84%) and a strong sea wind, commonly stormy but also low seasonal variations of temperature and few days of frost (7.3). The combined effect of the wind and the tides can generate

4515-669: The County of Shropshire , formerly also spelled Chirichburig (915) and Chiresbir (1226). The name of Octeville appears meanwhile, in 1063, in a Charter of William the Conqueror about allocations made to the Collegiate Church of Cherbourg. It means: "the rural area of Otti ", a Scandinavian male name also found in Octeville-l'Avenel , Octeville-sur-Mer and Otby (Lincolnshire, Ottebi , 11th century). Cherbourg

4620-579: The D650 takes a southwesterly direction to Les Pieux and then along to join the Côte des Isles (the Channel Islands coast) to Barneville-Carteret . In the approach to Cherbourg, this road has undergone development, in recent years, with amenities (roundabouts, traffic lights, urban development) by virtue of the peri-urbanisation of the communes in its path. With the awarding of autoroute status to

4725-634: The Dauphin's presence, and the Napoléon III basin (begun in 1836; 420×200×18 metres) on 7 August 1858 by Napoleon III and his wife. Work on the harbour was fully completed under the French Third Republic , with the addition of the eastern (1890–1894) and western (1889–1896) walls and the construction of a 'Petite rade' (digue du Hommet, 1899–1914, and digue des Flamands, 1921–1922). Charles Maurice Cabart Danneville made an entry point in

4830-485: The Department of Manche, it is the result of the merger of the communes of Cherbourg and Octeville. The amalgamated city today has an area of 14.26 km (5.506 sq mi). Cherbourg is situated at the mouth of the Divette  [ fr ] and at the south of the bay between Cap Lévi  [ fr ] to the east and Cap de La Hague to the west, Cherbourg-Octeville is 120 km (75 mi) from

4935-458: The English coast. Cherbourg and Octeville-sur-Cherbourg once belonged to the deanery of La Hague, delimited by the Divette. In 1786, a part of Equeurdreville joined Cherbourg, during the construction of the port, and then in 1802, a portion of Octeville. Since 1811, the " mielles " [dunes] of Tourlaville, commune of the deanery of Saire , are integrated into the Cherbourg territory known as

5040-615: The European Union safety standards (section 4.1.1.1 of the National Health and Engineering study) and radon emission levels well below the average outdoor radon concentrations in the US. Granite and related marble industries are considered one of the oldest industries in the world, existing as far back as Ancient Egypt . Major modern exporters of granite include China, India, Italy, Brazil, Canada, Germany, Sweden, Spain and

5145-713: The French ships under repair, including the Triomphant at the entry point into the port, the Admirable on the Mielles, and the Soleil Royal , the admiral's flagship, on the pointe du Hommet. The long-planned fortification of the town was finally set in motion by Louis XVI of France . In 1776, he set up a commission to choose between Cherbourg, Ambleteuse or Boulogne as France's main strategic port for defence of

5250-579: The German occupation and bombardment of the tram depot, the use of buses took over, and it was not until 1962 that the network had several lines. From 1976, the Communauté urbaine de Cherbourg supported the jurisdiction of public transit. Management of the public service is delegated to Keolis , the CTC took the name of Zephir Bus in 1991. The network covers the whole of the metropolitan area. In recent years,

5355-639: The Mohs hardness scale) , and tough. These properties have made granite a widespread construction stone throughout human history. The word "granite" comes from the Latin granum , a grain, in reference to the coarse-grained structure of such a completely crystalline rock. Granitic rocks mainly consist of feldspar , quartz , mica , and amphibole minerals , which form an interlocking, somewhat equigranular matrix of feldspar and quartz with scattered darker biotite mica and amphibole (often hornblende ) peppering

SECTION 50

#1732765879790

5460-570: The Penesme roundabout at Tourlaville and then a dual carriageway to a roundabout located between Collignon Beach and the Port des Flamands . An extension to Cherbourg is in the works, with the doubling of the bridge over the Port des Flamands , to ensure a continuity of the dual carriageway to the commercial port in Cherbourg. The old Route nationale 801  [ fr ] (reclassified as D901), which connects Cap de la Hague to Barfleur , crosses

5565-522: The RN13 in 2006, the work of upgrading to motorway standard between Cherbourg and Caen is being undertaken over a 10-year period. The construction work of the RN13 at the entrance of the Cherbourg agglomeration (locality Virage des Chèvres ) was completed in early 2009. Cherbourg-Octeville is a port on the English Channel with a number of regular passenger and freight ferry services operating from

5670-401: The United Kingdom , Napoleon I ordered that work on the harbour wall be resumed to La Bretonnière's plans, by building up the central section to mount cannon. A decree of 25 germinal year XI (1803) ordered the engineer Cachin to excavate the military outer harbour at lac de Moeris - this was opened on 27 August 1813 in the presence of empress Marie-Louise of Austria . That decree also ordered

5775-511: The United States. The Red Pyramid of Egypt ( c.  2590 BC ), named for the light crimson hue of its exposed limestone surfaces, is the third largest of Egyptian pyramids . Pyramid of Menkaure , likely dating 2510 BC, was constructed of limestone and granite blocks. The Great Pyramid of Giza (c. 2580 BC ) contains a huge granite sarcophagus fashioned of "Red Aswan Granite". The mostly ruined Black Pyramid dating from

5880-478: The airport had lost 30% of its commercial passengers, and 10% of its total traffic over a year. From the Empire , the coat of arms was accompanied by external ornaments: Mural crown with five rounds of argent, crest crossed fess a caduceus bypassed same on which are suspended two scallops used as mantling, one dexter olive, the other sinister oak, argent knotted and fastened by strips of azure. They also contain

5985-457: The armorial of d'Hozier in 1697, were added in the 18th century. Under the Empire, the coat of arms was completed by a free area of second-class towns which is to dexter azure to an "N" of or, surmounted by a pointed star of the same, brocading at the ninth of the escutcheon. Regarding the external ornaments, the mural crown symbolises protection and happiness, the caduceus of trade and business,

6090-419: The base of the chamber are the same ones that would crystallize anyway, but crustal assimilation is detectable in isotope ratios. Heat loss to the country rock means that ascent by assimilation is limited to distance similar to the height of the magma chamber. Physical weathering occurs on a large scale in the form of exfoliation joints , which are the result of granite's expanding and fracturing as pressure

6195-481: The beginning of the fourth century. Cherbourg Harbour 49°39′33″N 1°36′42″W  /  49.659072°N 1.611729°W  / 49.659072; -1.611729 Cherbourg Harbour (French: rade de Cherbourg ; literally, the " roadstead of Cherbourg ") is a harbour situated at the northern end of the Cotentin Peninsula , on the English Channel coastline, in Normandy , northwestern France . With

6300-418: The big difference in rheology between mafic and felsic magmas makes this process problematic in nature. Granitization is an old, and largely discounted, hypothesis that granite is formed in place through extreme metasomatism . The idea behind granitization was that fluids would supposedly bring in elements such as potassium, and remove others, such as calcium, to transform a metamorphic rock into granite. This

6405-462: The city from east to west. After the completion of the bypass east of the agglomeration, a western bypass project is under study, and a 'zone' corresponding to the future final route has been selected. Similarly, upgrading to a dual carriageway for access of Maupertus Airport is envisaged. The D650 is used to connect Cherbourg to the west coast of the Cotentin peninsula. Departing from Cherbourg,

SECTION 60

#1732765879790

6510-412: The coast. Three forts were added to its central wall in 1860. This and the two other breakwaters stretch for more than 6 km. The eastern opening into the harbour is 950 m wide and the western one 2.3 km wide. The harbour's maximum depth is 13 m at low tide. Cherbourg had been a strategic stronghold for several centuries - its castle was first built in the 5th century to protect the whole width of

6615-428: The coat of arms evokes the maritime trade of the city, the bezants - traditional furniture of the arms of ennobled financiers - represent wealth and fortune, while the star shows peace and prudence. The sable signifies prudence and constancy in adversity, the azure denotes activity and the seas. M. Canel had explained before him that the bezants and stars respectively illustrated trade and sea port. The stars, absent from

6720-537: The construction of a new arsenal at the port. 1803 also saw Cherbourg's harbour fend off British attacks and become a base for privateers. Works on the central wall were again interrupted between 1813 and 1832 and were only finally completed in 1853 under Napoleon III , with the western and eastern harbour walls only completed in 1895. The period also saw the opening of two basins in the naval base—the Charles X basin (begun in 1814; 290×220×18 metres) on 25 August 1829 in

6825-404: The division between S-type (produced by underplating) and I-type (produced by injection and differentiation) granites, discussed below. The composition and origin of any magma that differentiates into granite leave certain petrological evidence as to what the granite's parental rock was. The final texture and composition of a granite are generally distinctive as to its parental rock. For instance,

6930-473: The early 16th century became known as spolia . Through the process of case-hardening , granite becomes harder with age. The technology required to make tempered metal chisels was largely forgotten during the Middle Ages. As a result, Medieval stoneworkers were forced to use saws or emery to shorten ancient columns or hack them into discs. Giorgio Vasari noted in the 16th century that granite in quarries

7035-403: The engineer Louis-Alexandre de Cessart 's plans were chosen, which involved constructing a mole from 90 tree trunks 20m by 20m, filled in with stones and linked by iron chains. Construction began in 1783 and was completed in 70 years, by three architects - Louis-Alexandre de Cessart , La Bretonnière and Joseph Cachin . The first trunk was laid on 6 June 1784, one kilometre from Île Pelée, and

7140-443: The engineers, advised that Louis build a shorter harbour in a straight line between île Pelée and pointe du Hommet, as foreseen by Vauban, with a single central entry point, with the emphasis on military defences. In the end La Bretonnière's plan won, but during the construction phase Decaux argued for the merits of concrete masonry caissons whereas La Bretonnière preferred sinking old warships and building up rock around them. However,

7245-472: The first half of the 20th century, Cherbourg was the primary goal of US troops during the invasion of Normandy in 1944. Along with its use as a military, fishing and yachting port, it is also a cross-Channel ferry port, with routes to the English ports of Poole and Portsmouth , the Irish ports of Rosslare Harbour and Dublin , and St Helier on Jersey . Limited by its geographical isolation from being

7350-579: The first magma to enter solidifies and provides a form of insulation for later magma. These mechanisms can operate in tandem. For example, diapirs may continue to rise through the brittle upper crust through stoping , where the granite cracks the roof rocks, removing blocks of the overlying crust which then sink to the bottom of the diapir while the magma rises to take their place. This can occur as piecemeal stopping (stoping of small blocks of chamber roof), as cauldron subsidence (collapse of large blocks of chamber roof), or as roof foundering (complete collapse of

7455-713: The grotto is a highly regarded piece of Buddhist art , and along with the temple complex to which it belongs, Seokguram was added to the UNESCO World Heritage List in 1995. Rajaraja Chola I of the Chola Dynasty in South India built the world's first temple entirely of granite in the 11th century AD in Tanjore , India . The Brihadeeswarar Temple dedicated to Lord Shiva was built in 1010. The massive Gopuram (ornate, upper section of shrine)

7560-438: The harbour was filled with 300 to 400 boats ferrying stone from the port at Becquet to the mole to build against the trunks. However, the first trunks were severely damaged by storms. On 22 June 1786 Louis XVI made his only trip away from Paris and Versailles to see how far work on the harbour had progressed and assisted in sinking the ninth stone section. Cessart's plans were finally scotched in 1788, with funding having run out and

7665-575: The harbour's eastern breakwater, the digue Collignon, so that fishing boats could get out of the harbour rapidly, in case of emergency. That entry point later became the passe Cabart-Danneville. The breakwaters also resisted demolition by the Germans in 1944 during the Battle of Cherbourg . On April 10, 1912, the British ocean liner RMS Titanic stopped at Cherbourg Harbour on it's maiden voyage. The ship

7770-479: The large modern ferry terminal and has a major artificial harbour . The following operators currently run services from the port: Cherbourg has previously had services operated by the following operators: The port welcomes some 30 cruise ships per year including the largest, thanks to a cruise terminal built in 2006 in the Gare Maritime de Cherbourg , which had opened in 1933 on the Quai de France next to

7875-766: The late Roman Empire , and the recovered remains would be the village between Cherbourg and Tourlaville , on the Mielles. The Cotentin Peninsula was the first territory conquered by the Vikings in their ninth century invasion. They developed Cherbourg as a port. After the Anglo-Scandinavian settlement, a new name appeared there in a still Latinised form: Carusburg Castellum (1026-1027, Fauroux 58) then Carisburg (1056–1066, Fauroux 214), Chiersburg ( William of Jumièges , v. 1070), Chieresburg ( Wace , Roman de Rou , v. 1175). Carusburg would mean "fortress of

7980-570: The lighter color minerals. Occasionally some individual crystals ( phenocrysts ) are larger than the groundmass , in which case the texture is known as porphyritic . A granitic rock with a porphyritic texture is known as a granite porphyry . Granitoid is a general, descriptive field term for lighter-colored, coarse-grained igneous rocks. Petrographic examination is required for identification of specific types of granitoids. Granites can be predominantly white, pink, or gray in color, depending on their mineralogy . The alkali feldspar in granites

8085-474: The lower crust , rather than by decompression of mantle rock, as is the case with basaltic magmas. It has also been suggested that some granites found at convergent boundaries between tectonic plates , where oceanic crust subducts below continental crust, were formed from sediments subducted with the oceanic plate. The melted sediments would have produced magma intermediate in its silica content, which became further enriched in silica as it rose through

8190-729: The lower continental crust at high thermal gradients. This leads to significant extraction of hydrous felsic melts from granulite-facies resitites. A-type granites occur in the Koettlitz Glacier Alkaline Province in the Royal Society Range, Antarctica. The rhyolites of the Yellowstone Caldera are examples of volcanic equivalents of A-type granite. M-type granite was later proposed to cover those granites that were clearly sourced from crystallized mafic magmas, generally sourced from

8295-435: The magma is inevitable once enough magma has accumulated. However, the question of precisely how such large quantities of magma are able to shove aside country rock to make room for themselves (the room problem ) is still a matter of research. Two main mechanisms are thought to be important: Of these two mechanisms, Stokes diapirism has been favoured for many years in the absence of a reasonable alternative. The basic idea

8400-426: The magma. Other processes must produce these great volumes of felsic magma. One such process is injection of basaltic magma into the lower crust, followed by differentiation, which leaves any cumulates in the mantle. Another is heating of the lower crust by underplating basaltic magma, which produces felsic magma directly from crustal rock. The two processes produce different kinds of granites, which may be reflected in

8505-408: The magmatic parent of granitic rock. The residue of the source rock becomes a granulite . The partial melting of solid rocks requires high temperatures and the addition of water or other volatiles which lower the solidus temperature (temperature at which partial melting commences) of these rocks. It was long debated whether crustal thickening in orogens (mountain belts along convergent boundaries )

8610-405: The mantle. Although the fractional crystallisation of basaltic melts can yield small amounts of granites, which are sometimes found in island arcs, such granites must occur together with large amounts of basaltic rocks. H-type granites were suggested for hybrid granites, which were hypothesized to form by mixing between mafic and felsic from different sources, such as M-type and S-type. However,

8715-521: The manufacture of rubble ( moellon  [ fr ] ) and blocks squared for lintels . The greenschist , whose colour comes from chlorite and sericite , are used mainly for roofing in Nord-Cotentin, but also masonry in Cherbourg. The Armorican sandstone of the Montagne du Roule is used for rubble and rockfill. Most of the many quarries, which opened in the metropolitan area for building

8820-700: The marsh" in Old Norse kjarr (marsh), and borg (castle, fortified town) or "city of the marais" in Old English ker (bog) and burgh (town). The element kjarr / ker is also found in Normandy in Villequier and Orcher . According to François de Beaurepaire, it comes rather from the Old English chiriche (spelled ċiriċe , Church) or [tch] is reduced to [s], as the commune of Chirbury , in

8925-545: The minimum threshold of passenger traffic was not met. As well as a main line station there was also the Gare Maritime Transatlantique station. This now forms part of the Cité de la mer . The Compagnie des transports de Cherbourg (CTC) was created in 1896, connecting the Place de Tourlaville and the Place du Château by a tramway  [ fr ] in Cherbourg, then to Urville . After

9030-418: The moderation. Summers are far cooler than expected by French standards. Historically, Cherbourg is at the western end of Route nationale 13 , which runs through the city by the "Rouges Terres" and the Avenue de Paris , from La Glacerie . In the 1990s, a deviation from the road, now European routes E03 and E46 , referred traffic through La Glacerie and Tourlaville on a three-way axis from La Glacerie, to

9135-773: The north-east on la Fauconniere (including " La Roche qui pend " ['the hanging rock']) and the Montagne du Roule  [ fr ] . These two cliffs are due to sea erosion in the Quaternary . The retreat of the sea then gave way to sand dunes and tidal marshes, destroyed by the urbanisation of the 17th and 19th centuries, identical to those of Collignon in Tourlaville. These rocks in the soil have been used for centuries in several ways: Crushed granite extracted in Querqueville and arkoses of Becquet, have been used for

9240-466: The olive tree of peace, the oak of strength, recalling the role of both the military and commercial port. The argent means that Cherbourg was a second class city under the Empire. It was the logo of the municipality until the merger with Cherbourg, which then took the logo of Cherbourg. Today, the municipality of Cherbourg-Octeville uses a logo, entitled "mouette musicale" [musical seagull]. Initially adopted by Cherbourg, it consists of

9345-524: The other patron of the city. The bezants would be the expression of the redemption of the captives, illustrating the participation of the notables of Cherbourg on the Third Crusade . The coat of arms of Cherbourg dates from the late 12th century, at the time of the Crusades . According to M. Le Poupet, which relies in particular on the works of Vulson de la Colombière and Ségoing , the content of

9450-441: The overlying crust. Early fractional crystallisation serves to reduce a melt in magnesium and chromium, and enrich the melt in iron, sodium, potassium, aluminum, and silicon. Further fractionation reduces the content of iron, calcium, and titanium. This is reflected in the high content of alkali feldspar and quartz in granite. The presence of granitic rock in island arcs shows that fractional crystallization alone can convert

9555-737: The quarter of Val-de-Saire where the Pasteur Hospital  [ fr ] and the Saint-Clement Church were built. Thus, Cherbourg-Octeville lies both in La Hague and in the Val de Saire. Like all Chantereyne and the area of the Mielles, the Cherbourg territory was reclaimed from the sea. Built at the level of the sea, the town developed at the foot of the Roule mountain (highest point of the old town) and la Fauconnière. Octeville

9660-736: The reign of Amenemhat III once had a polished granite pyramidion or capstone, which is now on display in the main hall of the Egyptian Museum in Cairo (see Dahshur ). Other uses in Ancient Egypt include columns , door lintels , sills , jambs , and wall and floor veneer. How the Egyptians worked the solid granite is still a matter of debate. Tool marks described by the Egyptologist Anna Serotta indicate

9765-420: The relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF classification ), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites ) contain almost no dark minerals. Granite is nearly always massive (lacking any internal structures), hard (falling between 6 and 7 on

9870-564: The risk factors in granite country and design rules relating, in particular, to preventing accumulation of radon gas in enclosed basements and dwellings. A study of granite countertops was done (initiated and paid for by the Marble Institute of America) in November 2008 by National Health and Engineering Inc. of USA. In this test, all of the 39 full-size granite slabs that were measured for the study showed radiation levels well below

9975-418: The rock's high quartz content and dearth of available bases, with the base-poor status predisposing the soil to acidification and podzolization in cool humid climates as the weather-resistant quartz yields much sand. Feldspars also weather slowly in cool climes, allowing sand to dominate the fine-earth fraction. In warm humid regions, the weathering of feldspar as described above is accelerated so as to allow

10080-414: The rocks often bear a close resemblance. Under these conditions, granitic melts can be produced in place through the partial melting of metamorphic rocks by extracting melt-mobile elements such as potassium and silicon into the melts but leaving others such as calcium and iron in granulite residues. This may be the origin of migmatites . A migmatite consists of dark, refractory rock (the melanosome ) that

10185-492: The roof of a shallow magma chamber accompanied by a caldera eruption.) There is evidence for cauldron subsidence at the Mt. Ascutney intrusion in eastern Vermont. Evidence for piecemeal stoping is found in intrusions that are rimmed with igneous breccia containing fragments of country rock. Assimilation is another mechanism of ascent, where the granite melts its way up into the crust and removes overlying material in this way. This

10290-600: The south, and Nouainville and Sideville to the south-west. Located at the end of the Armorican Massif , Cherbourg retains traces of the geologic formation, deformed granites and metamorphic schists of the Precambrian of Hercynian orogeny by the folding of the arkoses of the Cambrian and Armorican sandstone and shale of the Ordovician . These folds result in layers of sandstone tilted 45° towards

10395-439: The station to Lisieux via Caen and to Rennes via Saint-Lô . Intercités services to Paris-Saint-Lazare take three hours on average. From July 2009 to December 2010, a TGV Cherbourg – Dijon service operated, via Mantes and Roissy TGV . With one daily round-trip, it operated experimentally for three years and gave the people of Cherbourg direct access by rail to France's primary airport. The service ceased prematurely, as

10500-435: The surface than magmas of I-type granites, which are thus more common as volcanic rock (rhyolite). They are also orogenic but range from metaluminous to strongly peraluminous. Although both I- and S-type granites are orogenic, I-type granites are more common close to the convergent boundary than S-type. This is attributed to thicker crust further from the boundary, which results in more crustal melting. A-type granites show

10605-502: The uranium washes into the sediments from the granite uplands and associated, often highly radioactive pegmatites. Cellars and basements built into soils over granite can become a trap for radon gas, which is formed by the decay of uranium. Radon gas poses significant health concerns and is the number two cause of lung cancer in the US behind smoking. Thorium occurs in all granites. Conway granite has been noted for its relatively high thorium concentration of 56±6 ppm. There

10710-617: The use of flint tools on finer work with harder stones, e.g. when producing the hieroglyphic inscriptions. Patrick Hunt has postulated that the Egyptians used emery , which has greater hardness. The Seokguram Grotto in Korea is a Buddhist shrine and part of the Bulguksa temple complex. Completed in 774 AD, it is an artificial grotto constructed entirely of granite. The main Buddha of

10815-405: Was sufficient to produce granite melts by radiogenic heating , but recent work suggests that this is not a viable mechanism. In-situ granitization requires heating by the asthenospheric mantle or by underplating with mantle-derived magmas. Granite magmas have a density of 2.4 Mg/m , much less than the 2.8 Mg/m of high-grade metamorphic rock. This gives them tremendous buoyancy, so that ascent of

10920-564: Was supposed to occur across a migrating front. However, experimental work had established by the 1960s that granites were of igneous origin. The mineralogical and chemical features of granite can be explained only by crystal-liquid phase relations, showing that there must have been at least enough melting to mobilize the magma. However, at sufficiently deep crustal levels, the distinction between metamorphism and crustal melting itself becomes vague. Conditions for crystallization of liquid magma are close enough to those of high-grade metamorphism that

11025-492: Was too large to be properly docked there, so passengers were transported to Titanic with the smaller vessels SS Traffic and SS Nomadic . Among these passengers were John Jacob Astor IV and his wife Madeline . The ship would later sink on it's voyage. Granite Granite ( / ˈ ɡ r æ n ɪ t / GRAN -it ) is a coarse-grained ( phaneritic ) intrusive igneous rock composed mostly of quartz , alkali feldspar , and plagioclase . It forms from magma with

#789210