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119-412: Covering an area of 47 720  km ( 18 420  sq mi), the region's terrain ranges diversely from permanent glaciers to verdant valleys, rich pasture lands and orchards, through to the arid steppes of the central lowlands. Aragon is home to many rivers—most notably, the river Ebro , Spain's largest river in volume, which runs west–east across the entire region through the province of Zaragoza. It

238-563: 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

357-520: 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,

476-593: A first Aiguabarreig between the towns of La Granja d'Escarp, Massalcoreig and Torrente de Cinca, a few kilometers downstream they converge with the waters of the Ebro, already in the municipality of Mequinenza , forming one of the largest river confluences of the entire Iberian Peninsula. Aragon, occupying the northeast of the Iberian Peninsula has served as a bridge between the Mediterranean Sea ,

595-610: 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

714-512: 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

833-565: 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

952-501: A lot with the cierzo . Temperatures in summer can exceed 40 °C in the central areas. In mountain areas winters are long and rigorous, average temperatures can be up to 10 °C lower than in the valley. The two most important winds of Aragon are the cierzo and the bochorno or levant . The first is a cold and dry wind that crosses the Ebro Valley from northwest to southeast and that can become quite strong. The second

1071-824: 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

1190-718: A paradise for biodiversity. Territorially, the Aiguabarreig is at the center of the Middle Depression of the Ebro. It borders to the west with the Monegros, to the east with the Tossals de Montmeneu and Almatret and to the south with the tail of the Ribarroja reservoir. This space is named with Catalan word of origin that designates the place where two or more water streams meet and form one. The Segre and Cinca form

1309-536: 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

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1428-568: 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

1547-657: A rather dry climate. Summers of the Ebro Valley most often mirror those of a semiarid climate ; some of them see more breaks of storms or showers, yet others are more arid , bringing drought save where advanced irrigation is used. The valley flood plains experience annual rainfall between 300 and 600 mm (12–24 in), with maxima in fall and spring. It is often covered with chaparral vegetation. Summers are hot and winters are cold. The dry summer season has temperatures of more than 35 °C (95 °F), occasionally reaching over 40 °C (104 °F). In winter,

1666-415: 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

1785-602: A wide lowland area, which is also the central part of the Depression of the Ebro . North of the river there is the Sierra de Alcubierre ranges ( 811 m ) one of the typical limestone plateaus of the valley. The Ebro Valley is a tectonic pit filled with sedimentary materials, accumulated in the Tertiary age in horizontal series. In the center, fine materials such as clays , plasters and limestones were deposited. To

1904-545: A wider river valley among limestone rocks when it reaches La Rioja and Navarre . Southern tributaries rise on the nearby watershed , the Sistema Ibérico , a mountain range among those of Spain's centre. North of the headwaters is the Cantabrian mountain range (south of Bilbao and Santander ). Much of the total water volume of the Ebro comes from its northern tributaries, which drain about 2 ⁄ 3 of

2023-466: 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

2142-545: 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

2261-517: 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

2380-704: Is a river of the north and northeast of the Iberian Peninsula , in Spain . It rises in Cantabria and flows 930 kilometres (580 mi), almost entirely in an east-southeast direction. It flows into the Mediterranean Sea , forming a delta in the Terres de l'Ebre region, in southern Catalonia . In the Iberian peninsula, it ranks second in length after the Tagus and second in discharge volume , and drainage basin , after

2499-426: Is a warm wind, more irregular and smooth, coming from the south-east. The vegetation follows the oscillations of relief and climate. There is a great variety, both in natural vegetation and in crops. In the high areas there are forests (pines, firs, beech trees, oaks), bush and meadows, and in the central Ebro Valley , evergreen oak and juniper are the most common trees. Most Aragonese rivers are tributaries of

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2618-528: Is also home to the highest mountains of the Pyrenees . As of January 2021, the population of Aragon was 1 326 261 , with slightly over half living in the capital city, Zaragoza . In 2020, the economy of Aragon generated a GDP of €34 687 million, which represents 3.1% of Spain's national GDP, and is currently 6th in per capita production behind Madrid, Basque Country , Navarre , Catalonia and La Rioja. In addition to its three provinces, Aragon

2737-627: Is an end from extreme temperatures accompanied by slow-growing dwarf juniper species to unvegetated desert steppes as in "llanos de Belchite" or "Calanda desert". The mountain vegetation is mostly coniferous forests that are drought-adapted, and hardier trees in the oak genus ( Quercus ), typically less tolerant, in the wetter highlands. Halophiles ( extremophiles as to salt) abound in zones of endorheic lagoons and their feeder creeks. Tamarix -covered, these include endemic species of bryophytes , chenopodiaceas, plumbaginaceae , ruppiaceaes, Carex , lythraceaes, asteraceaes, and others. Their presence

2856-410: 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

2975-535: Is attributable to its ability to colonise disturbed habitats that would deter the edible iberian crayfish . The semiaquatic rodent Myocastor coypus is beginning to expand in some northwest tributaries of the head damaging crops and protected national parks in the Basque Country . Fish caught in all lower reaches of the Ebro are high in mercury and the European Union prohibits their sale, notably

3094-637: 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

3213-434: 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

3332-501: Is causing the erosion of the coastline and lack of sediment replenishment. The unstable surface is due to weather changes and tidal surges . The river floods from time to time, although advance warning can now be given as a result of monitoring within the catchment area. The river flow in Zaragoza during floods, from the end of the 19th century is as follows: The Ebro poured 1,874 million cubic metres (1,519,000 acre-feet ) into

3451-654: Is formed by elevated terrain (from 1 000 to 2 000  m in general), but flattened and massive. To the southwest of the depression the summits of the Sierra de Albarracín range are reached above 1 800  m , southeast the 2 000  m are reached in the Sierra de Javalambre range and finally the Sierra de Gúdar range ( 2 024  m ) transitions to the Maestrazgo area in the Valencian Community . There are two main types of climate in Aragón,

3570-433: 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

3689-574: Is of international importance for 8 of its plant species and 69 of its vertebrate fauna. It has some 95 breeding species of birds, is also very important for a wide range of overwintering species, and serves as an essential stopover point for large numbers of migratory birds. The Ebro delta has the world's largest colony of Audouin's gulls . In 2006 it held a record number of more than 15,000 pairs, its highest to date. The introduction of American crayfish Procambarus clarkii has resulted in economic losses, introduced elsewhere for cultivation, its success

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3808-404: 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

3927-686: Is presence of Phoenician , Greek and Etruscan products. In the 6th century BCE there are six groups with different social organization: Vascones , Suessetani , Sedetani , Iacetani , Ilergetes and Citerior Celtiberians . They are Iberized groups with a tendency towards stability, fixing their habitat in durable populations, with dwellings that evolve towards more enduring and stable models. There are many examples in Aragon, among them Cabezo de Monleón in Caspe , Puntal of Fraga , Roquizal del Rullo or Loma de los Brunos. The type of social organization

4046-427: Is related to the marine origin of the valley and the extensive marine deposits. Just as it enters Catalonia, the valley narrows, and the river becomes constrained by mountain ranges, making wide bends. 3 massive dams have been built in this area: Mequinenza dam ( Province of Zaragoza , 1955), Riba-roja dam (1955), and Flix dam (1948), the latter two in the province of Tarragona . In the final section of its course

4165-454: 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

4284-411: 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

4403-533: Is subdivided into 33 comarcas or counties. All comarcas of Aragon have a rich geopolitical and cultural history from its pre-Roman , Celtic and Roman days, four centuries of Islamic rule as Marca Superior of Al-Andalus or kingdom (or taifa ) of Saraqusta , as lands that once belonged to the Frankish Marca Hispanica , counties that later formed the Kingdom of Aragon , and eventually

4522-479: 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

4641-410: 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

4760-517: Is the most important river in Spain in terms of length, 928 km (577 mi), and area of drainage basin, 85,550 km (33,030 sq mi). However, the mean annual flow decreased by approximately 29 percent during the 20th century due to many causes: the construction of dams, the increasing demands for irrigation and the evaporation (higher than the rainfall, due to low rainfall, high sunshine and strong and dry winds) from reservoirs in

4879-459: 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

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4998-428: 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

5117-680: The Biosphere Reserve of Ordesa-Viñamala and is cataloged as a World Heritage Site by UNESCO . In addition there are 4 other natural parks: the Moncayo Natural Park with an extension of 11 144  ha , the Sierra y Cañones de Guara Natural Park with 47 453  ha and 33 286  ha of peripheral area of protection, the Posets-Maladeta Natural Park with 33 440 .6 ha and 5 920 .2 ha of peripheral area of protection, and

5236-533: The Bronze Age by Pyrenees until reaching the Lower Aragon area, supposed an important ethnic contribution that prepared the way to the invasions of Iron Age. The Mediterranean contributions represented a commercial activity that will constitute a powerful stimulus for the iron metallurgy, promoting the modernization of the tools and the indigenous armament, replacing the old bronze with the iron. There

5355-460: The Crown of Aragon . The area of Aragon is 47 720  km of which 15 636  km belong to the province of Huesca , 17 275  km to the province of Zaragoza and 14 810  km to the province of Teruel . The total represents a 9.43% of the surface of Spain, being thus the fourth autonomous community in size behind Castile and León, Andalusia, and Castile-La Mancha. It is located in

5474-746: The Douro . It is the longest river entirely within Spain; the other two mentioned flow into Portugal . The Ebro flows through many cities ( Spanish : ciudades ): Reinosa in Cantabria ; Frías and Miranda de Ebro in Castile and León ; Haro , Logroño , Calahorra , and Alfaro in La Rioja ; Tudela in Navarre ; Alagón , Utebo , and Zaragoza in Aragon ; and Flix , Móra d'Ebre , Benifallet , Tivenys , Xerta , Aldover , Tortosa , and Amposta in

5593-784: The Ebro River, which is the largest river in Spain and divides the community in two. Of the tributaries of the left bank of the river, the ones originating in the Pyrenees, the Aragón River stands out. Its headwaters are in Huesca, but it ends at the community of Navarre, the Gállego and the Cinca , which joins the Segre just before emptying into the Ebro at the height of Mequinenza . On

5712-576: The Pyrenees to the north and the Sistema Ibérico mountain range to the south; the Community has the highest peaks of both mountain ranges, the Aneto and the Moncayo respectively. The Aragonese Pyrenees are located in the north of the province of Huesca and are arranged longitudinally in three large units: High Pyrenees, Internal Depressions and Outer Ranges. The Aragonese High Pyrenees contains

5831-523: The Second Punic War . One of the earliest Cistercian monasteries in Spain, Real Monasterio de Nuestra Señora de Rueda ( lit.   ' Royal ' Monastery of Our Lady of the Wheel), is located on the banks of the Ebro in Aragon . Established in 1202, the edifice survives intact. The monastery is strongly connected to the Ebro, since it used one of the first large waterwheels built for

5950-808: The Semi-arid climate and the Oceanic climate . Its irregular orography creates several microclimates throughout the entire community. From the High mountain Alpine climate of the central Pyrenees to the north, with perpetual ice (glaciers), to the Humid subtropical climate (which is very common in Huesca 's lower altitude areas) to the steppe or semi-desert zones , such as the Monegros Desert , passing through

6069-827: The Suessetani , to those who took the capital, Corbio. In the 1st century BCE Aragon was the scene of the civil war to seize the power of Rome where the governor Quintus Sertorius made Osca ( Huesca ) the capital of all the territories controlled by them. Already in the 1st century BCE, the today Aragonese territory became part of the province Tarraconensis and there was the definitive romanization of it creating roads and consolidating ancient Celtiberian and Iberian cities such as Caesaraugusta (Zaragoza), Turiaso ( Tarazona ), Osca ( Huesca ) or Bilbilis (Calatayud). Ebro The Ebro ( Spanish and Basque [ˈeβɾo] ; Catalan : Ebre , Western: [ˈeβɾe] , Eastern: [ˈeβɾə] )

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6188-484: The Terres de l'Ebre ('Ebro Lands') region, Catalonia , is at 340 km (130 sq mi), or 20km² less, one of the largest wetlands of the western Mediterranean. Designated a Ramsar site , it has entirely grown on soils washed downriver—the historical rate of growth of the delta is demonstrated by the town of Amposta . Recorded and thus confirmed as a seaport in the Roman Warm Period in

6307-632: The Valles Occidentales Natural Park with 27 073  ha and 7 335  ha of peripheral area of protection. There are also three nature reserves, five natural monuments and three protected landscapes. At the confluence of the Segre and Ebro rivers, the Aiguabarreig Ebro-Segre-Cinca is a space with great natural wealth and a great variety of ecosystems that range from Mediterranean steppes to impenetrable riverside forests, making this space

6426-790: The maximum heights of all the Pyrenees mountainous chain. The High Pyrenees is formed in turn by the axial Pyrenees and the Inland Ranges. In the axial Pyrenees are the oldest materials: granites , quartzites , slates and limestones and the highest peaks like: the Aneto ( 3 404  m ), Maladeta ( 3 309  m ) and the Perdiguero ( 3 221  m ). The inner Pre-Pyrenees, composed of more modern rocks (limestones) also has large mountains such as Monte Perdido ( 3 355  m ), Collarada ( 2 886  m ) and Tendeñera ( 2 853  m ). The main Pyrenean valleys are formed by

6545-690: The province of Tarragona ( Catalonia ). The source of the river Ebro is in the Cantabrian Mountains , in Fontibre , Cantabria ( Fontibre is from Latin Fontes Iberis , i.e. 'source of the Ebro'). Close by is a large artificial lake , Embalse del Ebro , created by its damming. The upper Ebro rushes through rocky gorges in Burgos Province . Flowing roughly eastwards it passes las conchas de Haro and begins forming

6664-459: The 4th century, it is now well inland from the mouths. The rounded form of the delta attests to the subsequent balance between sediment deposition by the Ebro and removal of this material by wave erosion . The modern delta is in intensive agricultural use for rice, fruit (in particular citrus), and vegetables. The Ebro delta also has numerous beaches, marshes, and salt pans that provide habitat for over 300 species of birds. The Ebro delta

6783-571: 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

6902-716: The Acheulean industry that found its best weapons in the hand axes of flint or the cleavers of quartzite . In the Upper Palaeolithic appeared two new cultures: Solutrean and Magdalenian. The Epipaleolithic was centered in Lower Aragon , occupying the epoch between the 7th and the 5th millennium. In the first half of the 5th millennium BCE , Neolithic remains are found in the Huescan Outer Ranges and in Lower Aragon. The Eneolithic

7021-690: The Cave del Moro of Olvena , the Masada del Ratón in Fraga , Palermo and the Cabezo de Monleón in Caspe . From the metallurgical point of view there seems to be a boom given the increase in foundry molds that are located in the populations. The Iron Age is the most important, since throughout the centuries it is the true substratum of the Aragonese historical population. The arrival of Central Europeans during

7140-917: The Ebro River, the Tagus River (which originates in the Sierra de Albarracín range), and the Júcar , which has as its main river in this community the Turia . In Aragon, protected natural spaces are managed through the Red Natural de Aragón , an entity created in 2004 to protect all elements with ecological , landscape and cultural value and at the same time coordinate and establish common standards that contribute to their conservation and sustainable use. In this entity are integrated national parks , natural parks , nature reserves , biosphere reserves and other protected natural areas that have been declared by

7259-408: The Ebro that Wels catfish have not colonized were not affected. The ecology of the river also now has the problem of a major increase in aquatic vegetation, seaweed and algae. 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

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7378-615: 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

7497-639: 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

7616-448: 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

7735-483: The Wels catfish's introduction in the Mequinenza reservoir in 1974, it has spread to other parts of the Ebro and its tributaries, especially the Segre . Some endemics species of iberian barbels , genus Barbus in the Cyprinidae , have declined drastically, having once been abundant, especially in the Ebro. Competition and predation by Wels catfish caused its complete disappearance in the middle channel Ebro around 1990. Barbel species from mountain stream tributaries of

7854-414: The area were rebelling, except for the Ilergetes who negotiated peace with Cato. There were different uprisings of the Iberian peoples against the Romans, in 194 BCE sees a general uprising with elimination of half of the Roman army, in 188 BCE Manlius Acidinus Fulvianus , praetor of the Citerior, must confront in Calagurris ( Calahorra ) with the Celtiberians , in the 184 BCE Terentius Varro did it with

7973-456: The autonomous community, the Ramsar Convention or the Natura 2000 . Within the protected areas is the only national park of Aragon: the Ordesa y Monte Perdido National Park , the second national park created in Spain , in 1918, it is found in the Pyrenees in the comarca of Sobrarbe , occupies an area of 15 608   ha , a part of the 19 679  ha of the peripheral area of protection. It also enjoys other figures of protection like

8092-419: 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

8211-418: 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

8330-775: The central Pyrenees and the Iberian System discharge large amounts of water, especially in spring during the thawing season of the mountain snow. The biomes are diverse in these Mediterranean climate zones: Mediterranean forests, woodlands, and scrub . Hinterlands are particularly distinctive on account of extensive sclerophyll shrublands known as maquis , or garrigues. The dominant species are Quercus coccifera (in drier areas) and Quercus ilex . These trees form monospecific communities or communities integrated with Pinus , Mediterranean buckthorns , Myrtus , Chamaerops humilis , junipers , Pistacia , Rosmarinus , Thymus , and so on. The hinterland climate becomes progressively more continental and drier, and therefore there

8449-538: The delta from 27 March 2007 to 11 April 2007, with an average of 117 million cubic metres (95,000 acre-feet) per day. Academics and local government have criticised ecological impacts of: In past times numerous lagoons , endorheic saltwater ponds , and freshwater swamps and marshes were drained, dried or filled. Almost entire riparian forests were cleared for crops or for pulpwood forest plantations. Due to these changes numerous plant and animal species have disappeared. Due to dams and hydraulic canalization,

8568-659: The dividing line between Roman (north) and Carthaginian (south) expansions after the First Punic War (264–241 BC). When the Roman Republic , fearful of Hannibal 's growing influence in the Iberian Peninsula, made the city of Saguntum (considerably south of the Ebro) a protectorate of Rome, Hannibal viewed the treaty violation as an aggressive action by Rome and used the event as the catalyst to

8687-404: 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,

8806-407: The dynamics of the river have been altered and new scroll-bars , new oxbow lakes , and new abandoned meanders will not now be created. Over a period of time, many of these phenomena tend to dry out or fill in with sediments. Some small representatives of these river dynamics and wetlands are protected. The Ebro Delta Natural Park, covering 7,802 hectares (19,280 acres), was finalised in 1986 and

8925-473: 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

9044-454: The east with the autonomous communities of Catalonia (provinces of Lérida and Tarragona ) and the Valencian Community (provinces of Castellón and Valencia ). The orography of the community has as the central axis the Ebro valley (with heights between 150 and 300 meters approx.) which transits between two foothill areas, the Pyrenean and the Iberian, preambles of two mountain formations,

9163-599: The ecologic and economic resources of the delta. The Greeks called the river Ἴβηρ ( Ibēr ), abir , ah'ir and the Romans called it the Hibēr , Ibēr , or Ibērus flūmen , leading to its current name. The Iberian Peninsula and the Hibērī or Ibērī (the people of the area) were named after the river. It is not known with any certainty whether the Greeks used a local native name for

9282-579: 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

9401-713: 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)

9520-419: The huge Wels catfish . The zebra mussel , an invasive species , is expanding upstream in the Ebro's waters. Due to its rapid rate of reproduction, the species adversely affects the port's underwater machinery as well as that of dams and hydroelectric plants, in addition to competing with native species. Following the introduction of Wels catfish, many fish species' numbers are in clear and rapid decline. Since

9639-543: The intense continental climate of the Teruel-Daroca area and the Mediterranean climate in the southern areas bordering Castilla La Mancha and the Valencian Community . The main characteristics of the Aragonese climate are: Temperatures are very dependent on the altitude. In the Ebro Valley the winters are relatively moderate, although the frosts are very common and the thermal sensation can decrease

9758-639: The interior. In the territorial distribution that Rome made of Hispania , the current Aragon was included in the Hispania Citerior . In the year 197 BCE, Sempronius Tuditanus is the praetor of the Citerior and had to face a general uprising in their territories that ended with the Roman defeat and the own death of Tuditanus. In view of these facts the Senate sent the consul Marcus Porcius Cato with an army of 60 000 men. The indigenous peoples of

9877-570: 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

9996-474: 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

10115-729: 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

10234-435: 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

10353-426: 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

10472-408: 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 )

10591-405: 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,

10710-407: The mouth. In addition to decreased mean annual flow, the increased river regulation in the Ebro basin has produced daily and seasonal changes in the flow pattern. With regards to the sediment load, several authors conclude that the sediment load was reduced by more than 99 percent during the last century. The drastic reduction in sediment transport implies a sediment deficit in the delta, which

10829-402: The northeast of the Iberian Peninsula , at a latitude between 39º and 43º'N in the temperate zone . Its boundaries and borders are in the north with France (the regions of Nouvelle-Aquitaine and Occitanie ), in the west with the autonomous communities of Castile-La Mancha (provinces of Guadalajara and Cuenca ), Castile and León ( province of Soria ), La Rioja and Navarre , and in

10948-441: 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

11067-644: The peninsular center and the coasts of the Cantabrian Sea . The human presence in the lands that today form the autonomous community date back several millennia, but present-day Aragon, like many of the current historical nationalities, was formed during the Middle Ages . The oldest testimonies of human life in the lands that today make up Aragon go back to the time of the glaciations, in the Pleistocene , some 600 000 years ago. This population left

11186-671: The production of power in Spain. The monastery also diverted flow from the Ebro to create a circulating, hydrological central heating system for its buildings. The Ebro in 1938 was the starting ground of one of the most famous Republican offensives of the Spanish Civil War . Known as the Battle of the Ebro , the offensive ended in defeat for the Republican forces, although they enjoyed success in its first stages. They were not able to reach their objective of Gandesa . The Ebro

11305-736: 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

11424-420: 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

11543-644: The right bank, the Jalón , Huerva and Guadalope stand out. In the stream bed of the Ebro river, near the border with Catalonia, the Mequinenza Reservoir , of 1 530  hm and a length of about 110 km; it is popularly known as the "Sea of Aragon". The small Pyrenean mountain lakes called ibones merit special mention. These lakes are very scenic, originating during the last glaciation , and are usually found above 2 000  m . The Autonomous Community lies within three hydrographic regions,

11662-564: 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

11781-421: The river basins. This situation has a direct impact on the deltaic system at the mouth of the river because its hydrological dynamics are mainly controlled by the river discharge. The decrease in river discharge has meant introduction of the salt wedge further into the river. The mean annual river flow is approximately the critical flow which determines the formation and the break-up of the salt wedge. Thus, when

11900-614: The river bends southwards and flows through spectacular gorges. The calcareous cliffs and high, rocky hills of the Serra de Cardó almost abut the river separating the Mediterranean coastal strip. After passing the gorges, the Ebro bends again eastwards near Tortosa before discharging in a delta on the Mediterranean Sea close to Amposta in the province of Tarragona . The Ebro Delta (Catalan: Delta de l'Ebre ), in

12019-479: The river discharge is between 300 and 400 m /s (11,000 and 14,000 cu ft/s), the salt wedge can occupy the last 5 km (3 mi) of the estuary, but when the discharge is between 100 and 300 m /s (3,500 and 10,600 cu ft/s), the salt wedge can advance up to 18 km (11 mi) from the mouth. For less than 100 m /s (3,500 cu ft/s), the salt wedge quickly advances to its maximum extent, reaching 32 km (20 mi) from

12138-460: The river. Nor is it known what the word " Ibēr " or " Hibēr " might mean. In modern Basque the word ibar means 'valley' or 'watered meadow', while ibai means 'river', but there is no proof relating the etymology of the Ebro River with these Basque words. There are rivers in the Balkans called Ibar (Montenegro and Serbia) and Evros (Bulgaria and Greece). In antiquity , the Ebro was used as

12257-593: The rivers that are born there, which are: The intrapirenaic depression is a broad perpendicular corridor. Its best represented section is the Canal de Berdún , which limits on the south with the reliefs of San Juan de la Peña ( 1 552  m ) and Oroel Rock ( 1 769  m ), modeled on conglomerates of the Campodarbe Formation. The pre-Pyrenean outer ranges are in the Huescan foothills and constitute

12376-418: 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

12495-414: 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

12614-492: 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

12733-493: The south of the Ebro there are the limestone plateaus of Borja and of Zaragoza . The Aragonese section of the Sistema Ibérico straddles the provinces of Zaragoza and Teruel . It is a set of hills without a clear structural unit, which can be divided into two zones: Sistema Ibérico del Jalón and Sistema Ibérico turolense. In the first, the Moncayo stands out with 2 314  m , formed by Paleozoic quartzites and slates , partly covered by Mesozoic limestones . The second

12852-417: The southern slopes of the Pyrenees mountains, which run along the border with France . All of Andorra's drainage basin is in the Ebro, through the Segre . Downstream from Cantabria the climate in the Ebro basin – the valley being isolated from sea air masses by surrounding mountains – becomes Mediterranean/Atlantic influenced and continental . This implies summer/winter seasonal contrast and

12971-552: The southernmost unit of the Pyrenees; formed by predominantly calcareous materials, reach heights between 1 500 and 2 000 meters. The Sierra de Guara , one of the most important mountain ranges of the Spanish Pre-Pyrenees , stands out; its summit, the Guara Peak , reaches 2 077 metres. The Mallos de Riglos , near the town of Ayerbe , stand out for their beauty. The Aragonese central depression includes

13090-465: The surface is organically poor and quick-draining: calcareous, pebbly, stony layers. These are in places salt-rich, seeing some saltwater endorheic lagoons. Karst geological processes shaped the landscape of layers of soluble carbonate rock of extensive limestone bedrock formed in an ancient seabed. The valley expands and the Ebro's flow then becomes slower as its water volume increases, flowing across Aragon. There, larger tributaries flowing from

13209-435: 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

13328-417: The temperatures often drop below 0 °C (32 °F). In some areas the vegetation depends heavily on moisture produced by condensation fog . It is a continental Mediterranean climate with extreme temperatures. There are many ground frosts on clear nights, and sporadic snowfalls . The natural topsoils across the plains are, outside of historically well-forested zones, thin. The subsoil being close to

13447-502: 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

13566-617: 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

13685-469: Was based on the family group, consisting of four generations. Self-sufficient societies in which the greater part of the population was dedicated to agricultural and livestock activities. In the Iberian scope the power was monarchical, exercised by a king; there was a democratic assembly with participation of the male population. There were visible social differentiations and established legal-political statutes. The Romans arrived and progressed easily into

13804-723: Was characterized in the province of Huesca presenting two important megalithic nuclei: the Pre-Pyrenees of the Outer Ranges and the High Pyrenean valleys. The Late Bronze Age begins in Aragon around 1100 BCE with the arrival of the Urnfield culture . They are Indo-European people, with an alleged origin in Central Europe, who incinerate their dead by placing the ashes in a funeral urn. There are examples in

13923-493: Was classified as a wetland area of international interest by Spain's Bureau Mar in 1962. Since a phased-introduction law (1983 to 1986) Spain has designated 7,736 hectares (29.87 sq mi) as the Ebro Delta Natural Park (Catalan: Parc Natural del Delta de l'Ebre ) to protect its natural resources. A network of canals and irrigation ditches dug by agricultural and conservation groups help to maintain

14042-405: 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

14161-564: 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

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