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Millstätter See
Lake Millstatt (, sometimes written "Millstättersee") is a lake in Carinthia (state), Carinthia, Austria. Geography It is situated at 588 metres above the Adriatic (1,929 ft), north of the Drava Valley within the Gurktal Alps (Nock Mountains) range of the Central Eastern Alps, near the town of Spittal an der Drau. With a surface area of Lake Millstatt is the second largest lake of Carinthia (after Wörthersee, Lake Wörth), though with a depth of the most voluminous by far. Its steep shore gives the lake a fjord-like character. The Millstätter Alpe mountains in the north up to protect it from cold winds, so the water temperature can reach in summer. The narrow and long surface stretches over from east to west. In the south the wooded Hochgosch plateau, with a breadth of and an elevation of , divides the lake from the parallel Drava Valley. The name derives from the market town Millstatt on the northern shore. Other municipalities near the lake are Seeboden and Raden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carinthia (state)
Carinthia ( ; ; ) is the southernmost and least densely populated Austrian state, in the Eastern Alps, and is noted for its mountains and lakes. The Lake Wolayer is a mountain lake on the Carinthian side of the Carnic Main Ridge, near the Plöcken Pass.The main language is Austrian German, with its non-standard dialects belonging to the Southern Bavarian group; Carinthian Slovene dialects, forms of a South Slavic language that predominated in the southeastern part of the region up to the first half of the 20th century, are now spoken by a small minority in the area. Carinthia's main industries are tourism, electronics, engineering, forestry, and agriculture. Name The etymology of the name "Carinthia", similar to Carnia or Carniola, has not been conclusively established. The ''Ravenna Cosmography'' (about AD 700) referred to a Slavic "Carantani" tribe as the eastern neighbours of the Bavarians. In his ''History of the Lombards'', the 8th-century chronicler Paul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years from the end of the Cambrian Period Megaannum, Ma (million years ago) to the start of the Silurian Period Ma. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay Minerals
Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay minerals form in the presence of water and have been important to life, and many theories of abiogenesis involve them. They are important constituents of soils, and have been useful to humans since ancient times in agriculture and manufacturing. Properties Clay is a very fine-grained geologic material that develops plasticity when wet, but becomes hard, brittle and non–plastic upon drying or firing. It is a very common material, and is the oldest known ceramic. Prehistoric humans discovered the useful properties of clay and used it for making pottery. The chemistry of clay, including its capacity to retain nutrient cations such as potassium and ammonium, is important to soil fertility. Because the individual particles in clay are less t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz. Calcium carbonate is the second most common type of sand. One such example of this is aragonite, which has been created over the past 500million years by various forms of life, such as coral and shellfish. It is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years, as in the Caribbean. Somewhat more rarely, sand may be composed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphism
Metamorphism is the transformation of existing Rock (geology), rock (the protolith) to rock with a different mineral composition or Texture (geology), texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation. Metamorphism is distinct from weathering or diagenesis, which are changes that take place at or just beneath Earth's surface. Various forms of metamorphism exist, including Regional metamorphism, regional, Contact metamorphism, contact, Hydrothermal metamorphism, hydrothermal, Shock metamorphism, shock, and Dynamic metamorphism, dynamic metamorphism. These differ in the characteristic temperatures, pressures, and rate at which they take place and in the extent to which reactive fluids are involved. Metamorphism occurring at increasing pressure and temperature conditions is known as ''prograde metamorphism'', while decreasin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartzite
Quartzite is a hard, non- foliated metamorphic rock that was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts, and hence quartzite is a metasandstone. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and red due to varying amounts of hematite. Other colors, such as yellow, green, blue and orange, are due to other minerals. The term ''quartzite'' is also sometimes used for very hard but unmetamorphosed sandstones that are composed of quartz grains thoroughly cemented with additional quartz. Such sedimentary rock has come to be described as orthoquartzite to distinguish it from metamorphic quartzite, which is sometimes called metaquartzite to emphasize its metamorphic origins. Quartzite is very resistant to chemical weathering and often forms ridges and resist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schist
Schist ( ) is a medium-grained metamorphic rock generally derived from fine-grained sedimentary rock, like shale. It shows pronounced ''schistosity'' (named for the rock). This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture (geology), texture reflects a high content of platy minerals, such as mica, talc, chlorite group, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz. Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium Metamorphism#Metamorphic grades, grade of metamorphism. Schist can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schis ... [...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] |
Austroalpine Nappes
The Austroalpine nappes are a geological nappe stack system in the European Alps. They structurally on top of the Penninic (meaning they were thrust over them). The prefix Austro in this term refers to Austria, rather than south/southern. This is because the bulk of the Austroalpine nappes (which constitute the Eastern Alps except for some tectonic windows) is in Austria, although they also reach into Eastern Switzerland. The western boundary of the Eastern Alps is the Lake Constance - Chur – Lake Como line. Geographic position and nappes in the Western Alps The Austroalpine nappes constitute the Eastern Alps, except for some tectonic windows such as the Tauern window, the Rechnitz window (both in Austria) and the Engadin window (Switzerland). They cover eastern Switzerland and the largest part Austria. In the Western Alps the Sesia (Italy) and the Dent Blanche (Switzerland) units form a klippe over the Penninic nappes. They have been labelled as Austroalpine becaus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kettle (landform)
A kettle (also known as a kettle hole, kettlehole, or pothole) is a depression or hole in an outwash plain formed by retreating glaciers or draining floodwaters. The kettles are formed as a result of blocks of dead ice left behind by retreating glaciers, which become surrounded by sediment deposited by meltwater streams as there is increased friction. The ice becomes buried in the sediment and when the ice melts, a depression is left called a kettle hole, creating a dimpled appearance on the outwash plain. Lakes often fill these kettles; these are called kettle hole lakes. Another source is the sudden drainage of an ice-dammed lake and when the block melts, the hole it leaves behind is a kettle. As the ice melts, ramparts can form around the edge of the kettle hole. The lakes that fill these holes are seldom more than deep and eventually fill with sediment. In acidic conditions, a kettle bog may form but in alkaline conditions, it will be Mire, kettle peatland. Overview Kettles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meltwater
Meltwater (or melt water) is water released by the melting of snow or ice, including glaciers, glacial ice, tabular icebergs and ice shelf, ice shelves over oceans. Meltwater is often found during early spring (season), spring when snow packs and cryosphere#Lake ice and river ice, frozen rivers melt with rising temperatures, and in the ablation zone of glaciers where the rate of snow cover is reducing. Meltwater can be produced during volcanic eruptions, in a similar way in which the more dangerous lahars form. It can also be produced by the heat generated by the flow itself. When meltwater pools on the surface rather than flowing, it forms melt ponds. As the weather gets colder meltwater will often re-freeze. Meltwater can also collect or melt under the ice's surface. These pools of water, known as subglacial lakes can form due to geothermal heat and friction. Melt ponds may also form above and below Arctic sea ice, decreasing its albedo and causing the formation of thin underw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
