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Barre Des Écrins
The Barre des Écrins () is a mountain in the French Alps with a peak elevation of . It is the highest peak of the Massif des Écrins and the Dauphiné Alps and the most southerly alpine peak in Europe that is higher than 4,000 metres. It is the only 4,000-metre mountain in France that lies outside the Mont Blanc Massif. Before the annexation of Savoy in 1860 it was the highest mountain in France. Geography Location The Barre des Écrins is the highest peak in the Provence-Alpes-Côte d'Azur region including all of Occitania and the Southern Alps. It is located in the commune of Pelvoux and is situated near the Drainage divide between the Durance and the ''Vénéon''. This divide passes 250 metres west of the summit, along the ridge that leads to the summit of the sub-peak ''Dôme des Écrins'' (4088 metres). The south face of the mountain is rocky while the north face is ice as it is the starting point of the Glacier Blanc. The mountain is surrounded by four glaciers: to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra Prominent Peak
An ultra-prominent peak, or ultra for short, is a mountain summit with a topographic prominence of or more; it is also called a P1500. The prominence of a peak is the minimum height of climb to the summit on any route from a higher peak, or from sea level if there is no higher peak. There are approximately 1,500 such peaks on Earth. Some well-known peaks, such as the Matterhorn and Eiger, are not ultras because they are connected to higher mountains by high cols and thus do not achieve enough topographic prominence. The term "ultra" originated with earth scientist Steve Fry, from his studies of the prominence of peaks in Washington (state), Washington in the 1980s. His original term was "ultra major mountain", referring to peaks with at least of prominence. Distribution Currently, over 1,500 ultras have been identified above sea level: 654 in Asia, 357 in North America, 209 in South America, 119 in Europe (including 12 in the Caucasus), 84 in Africa, 54 in Oceania, and 39 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drainage Divide
A drainage divide, water divide, ridgeline, watershed, water parting or height of land is elevated terrain that separates neighboring drainage basins. On rugged land, the divide lies along topographical ridges, and may be in the form of a single range of hills or mountains, known as a dividing range. On flat terrain, especially where the ground is marshy, the divide may be difficult to discern. A triple divide is a point, often a summit, where three drainage basins meet. A ''valley floor divide'' is a low drainage divide that runs across a valley, sometimes created by deposition or stream capture. Major divides separating rivers that drain to different seas or oceans are continental divides. The term ''height of land'' is used in Canada and the United States to refer to a drainage divide. It is frequently used in border descriptions, which are set according to the "doctrine of natural boundaries". In glaciated areas it often refers to a low point on a divide where it is po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oisans
L'Oisans () is a region in the French Alps, located in the départements of l'Isère and Hautes-Alpes, and corresponding to the drainage basin of the River Romanche and its tributaries (Eau d'Olle, Lignarre, Sarenne, Vénéon and Ferrand). Between Livet-et-Gavet and Le Bourg-d'Oisans, the Romanche forms a deep gorge. Description Its geographical definition coincides almost exactly with the former cantons of Canton of Le Bourg-d'Oisans, Le Bourg-d'Oisans (Isère) and Canton of La Grave, La Grave (Hautes Alpes). The Oisans covers parts of the massifs of Belledonne, Taillefer Massif, Taillefer, Grandes Rousses, Arves massif, Arves and Massif des Écrins, Écrins. The highest point in the region is the mountain of ''Pic Lory'', a subpeak of the Barre des Écrins which reaches a height of 4,088 metres, but the most symbolic peak is la Meije which is nicknamed the "Queen of the Oisans". The Oisans is a remarkable territory, thanks to its numerous mountain chains, valleys, rivers, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kingdom Of Sardinia
The Kingdom of Sardinia, also referred to as the Kingdom of Sardinia and Corsica among other names, was a State (polity), country in Southern Europe from the late 13th until the mid-19th century, and from 1297 to 1768 for the Corsican part of this kingdom. The kingdom was a member of the Council of Aragon and initially consisted of the islands of Corsica and Sardinia, sovereignty over both of which was claimed by the papacy, which granted them as a fief, the (Kingdom of Sardinia and Corsica), to King James II of Aragon in 1297. Beginning in 1324, James and his successors Aragonese conquest of Sardinia, conquered the island of Sardinia and established ''de facto'' their ''de jure'' authority. In 1420, after the Sardinian–Aragonese war, the last competing claim to the island was bought out. After the union of the crowns of Aragon and Crown of Castile, Castile, Sardinia became a part of the burgeoning Spanish Empire. In 1720, the island and its kingdom were ceded by the House o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluton
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California. Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained ( phaneritic). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid is particularly important in classifying intrusive igneous rocks. Intru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with 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 dike (geology), 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 the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF diagram, 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) conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibole
Amphibole ( ) is a group of inosilicate minerals, forming prism or needlelike crystals, composed of double chain tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures. Its IMA symbol is Amp. Amphiboles can be green, black, colorless, white, yellow, blue, or brown. The International Mineralogical Association currently classifies amphiboles as a mineral supergroup, within which are two groups and several subgroups. Mineralogy Amphiboles crystallize into two crystal systems, monoclinic and orthorhombic. In chemical composition and general characteristics they are similar to the pyroxenes. The chief differences from pyroxenes are that (i) amphiboles contain essential hydroxyl (OH) or halogen (F, Cl) and (ii) the basic structure is a double chain of tetrahedra (as opposed to the single chain structure of pyroxene). Most apparent, in hand specimens, is that amphiboles form oblique cleavage planes (at around 120 degrees), wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feldspar
Feldspar ( ; sometimes spelled felspar) is a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldspars and the ''alkali'' (potassium-sodium) feldspars. Feldspars make up about 60% of the Earth's crust and 41% of the Earth's continental crust by weight. Feldspars crystallize from magma as both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar is known as anorthosite. Feldspars are also found in many types of sedimentary rocks. Etymology The name ''feldspar'' derives from the German , a compound of the words ' ("field") and ("flake"). had long been used as the word for "a rock easily cleaved into flakes"; was introduced in the 18th century as a more specific term, referring perhaps to its comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of Silicon dioxide, SiO2. Quartz is, therefore, classified structurally as a Silicate mineral#Tectosilicates, framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gneiss
Gneiss (pronounced ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. This rock is formed under pressures ranging from 2 to 15 kbar, sometimes even more, and temperatures over 300 °C (572 °F). Gneiss nearly always shows a banded texture characterized by alternating darker and lighter colored bands and without a distinct Cleavage (geology), cleavage. Gneisses are common in the ancient crust of Continental Shield, continental shields. Some of the oldest rocks on Earth are gneisses, such as the Acasta Gneiss. Description image:Orthogneiss Geopark.jpg, Orthogneiss from the Czech Republic In traditional English and North American usage, a gneiss is a coarse-grained metamorphic rock showing compositional banding (gneissic banding) but poorly developed schistosity and indistinct Cleavage (geology), cleavage. In other words, it i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Migmatite
Migmatite is a composite rock (geology), rock found in medium and high-grade metamorphic environments, commonly within Precambrian craton, cratonic blocks. It consists of two or more constituents often layered repetitively: one layer is an older metamorphic rock that was reconstituted subsequently by partial melting ("paleosome"), while the alternate layer has a Pegmatite, pegmatitic, Aplite, aplitic, Granite, granitic or generally plutonic appearance ("neosome"). Commonly, migmatites occur below deformed metamorphic rocks that represent the base of eroded mountain chains. Migmatites form under extreme temperature and pressure conditions during Metamorphism#Prograde and retrograde, prograde metamorphism, when partial melting occurs in metamorphic paleosome. Components Solid solution, exsolved by partial melting are called neosome (meaning ‘new body’), which may or may not be heterogeneous at the microscopic to macroscopic scale. Migmatites often appear as tightly, incoheren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacier Noir
The Glacier Noir ( French for "black glacier") is a glacier in the Massif des Écrins in the French Alps. It is located in the département of Hautes-Alpes. Geography Of all the great glaciers in the Oisans region, the Glacier Noir is the one that descends furthest into the valley. This is thanks to favourable topography and the fact that the lower tongue of the glacier is entirely covered with ablation moraine. As a result, it is better screened from direct sunshine than, for example, its neighbour, the Glacier Blanc ("white glacier"). Until at least 1866 the Glacier Noir and Glacier Blanc were combined into a single glacial systemAccording to other sources the separation of the Glacier Blanc and the Glacier Noir occurred in 1876, cf. above the ''Pré de Madame Carle''. But whilst the foot of the Glacier Blanc has currently retreated to a height of around , the snout of the Glacier Noir descends a further 200 metres in height to about .Vgl. Description avallouimages.com A gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
