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28-430: These mountains are a distinct physiographic province of the larger Alpine System physiographic division . The Cantabrian Mountains offer a wide range of trails for hiking , as well as many challenging climbing routes. Skiing is possible in the ski resorts of Alto Campoo , Valgrande-Pajares, Fuentes de Invierno, San Isidro, Leitariegos and Manzaneda. The Cantabrian Mountains stretch east-west, nearly parallel to

56-552: A specific character, relief, and environment which contributes to its distinctiveness. The physiographic provinces are then subdivided into smaller physiographic sections. In eastern North America , the Atlantic Coastal Plain , Piedmont , Blue Ridge Mountains , Ridge-and-Valley Appalachians , and Appalachian Plateau are specific physiographic provinces. In the Western United States of western North America:

84-521: A suitable artificial substrate for oysters in a reef-like environment. Marl has been used in the manufacture of Portland cement. It is abundant and yields better physical and mechanical properties than metakaolin as a supplementary cementitious material and can be calcined at a considerably lower temperature. The Channel Tunnel was constructed in the West Melbury Marly Chalk, a geological formation containing marl beds. This formation

112-482: A very low permeability , they have been exploited for construction of the Channel Tunnel between England and France and are being investigated for the storage of nuclear waste . Marl is one of the oldest soil amendments used in agriculture. In addition to increasing available calcium, marl is valuable for improving soil structure and decreasing soil acidity and thereby making other nutrients more available. It

140-673: Is calcite , but other carbonate minerals such as aragonite or dolomite may be present. Glauconitic marl is marl containing pellets of glauconite , a clay mineral that gives the marl a green color. Glauconite is characteristic of sediments deposited in marine conditions. The lower stratigraphic units of the chalk cliffs of Dover consist of a sequence of glauconitic marls followed by rhythmically banded limestone and marl layers. Such alternating cycles of chalk and marl are common in Cretaceous beds of northwestern Europe. The Channel Tunnel follows these marl layers between France and

168-495: Is formed in marine or freshwater environments, often through the activities of algae . Marl makes up the lower part of the cliffs of Dover , and the Channel Tunnel follows these marl layers between France and the United Kingdom. Marl is also a common sediment in post- glacial lakes , such as the marl ponds of the northeastern United States. Marl has been used as a soil conditioner and neutralizing agent for acid soil and in

196-461: Is today often used to describe indurated marine deposits and lacustrine (lake) sediments which more accurately should be named 'marlstone'. Marlstone is an indurated (resists crumbling or powdering) rock of about the same composition as marl. This is more correctly described as an earthy or impure argillaceous limestone . It has a blocky subconchoidal fracture, and is less fissile than shale . The dominant carbonate mineral in most marls

224-540: The Basin and Range Province , Cascade Range , Colorado Plateau , Rio Grande rift , Great Basin , Central Valley (California) , Peninsular Ranges , Los Angeles Basin , and Transverse Ranges are examples of physiographic provinces. This article about geography terminology is a stub . You can help Misplaced Pages by expanding it . Marl Marl is an earthy material rich in carbonate minerals , clays , and silt . When hardened into rock , this becomes marlstone . It

252-615: The Cantabrian brown bear ( Ursus arctos pyrenaicus ), catalogued as being in danger of extinction, which extends from Asturias (the region where its population is bigger) to areas in Léon , Palencia and Cantabria , and the Cantabrian capercaillie ( T. urogallus cantabricus ). Other animals associated with the range include the Iberian wolf ( Canis lupus signatus ) and the rebeco , or Cantabrian chamois ( Rupicapra pyrenaica parva ). Woodland in

280-623: The Cares River valley. Highest point Torre de Cerredo 2,648 m. The main mountains of this zone are the massive Picos de Europa . They are composed of Carboniferous limestone and marl . The Paramo de Masa and La Lora grasslands are located in the south crossed by the Rudrón Valley . The Basque Mountains at the eastern end of the system, with very eroded Mesozoic folds and ranges of moderate height: The Cantabrian Mountains are home to an important variety of plant life, as well as

308-655: The Picos de Europa , to which range the Peña Vieja also belongs, rises on the right bank of the Sella to a height of 8,045 feet (2,452 m); further west the peaks of Manpodres , Peña Ubiña , Peña Rubia and Cuiña all exceed 7,000 feet (2,100 m). A conspicuous feature of the chain, as of the adjacent tableland, is the number of its parameras, isolated plateaus shut in by lofty mountains or even by precipitous walls of rock. The Cantabrian Mountains sharply divide " Green Spain ", to

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336-464: The 18th century. The marl was normally extracted close to its point of use, so that almost every field had a marl pit, but some marl was transported greater distances by railroad. However, marl was gradually replaced by lime and imported mineral fertilizers early in the 19th century. A similar historical pattern was seen in Scotland. Marl was one of a few soil amendments available in limited quantities in

364-482: The 21st century, though less frequently. The rate of application must be adjusted for the reduced content of calcium carbonate versus straight lime, expressed as the calcium carbonate equivalent. Because the carbonate in marl is predominantly calcium carbonate, magnesium deficiency may be seen in crops treated with marl if they are not also supplemented with magnesium. Marl has been used in Pamlico Sound to provide

392-657: The Cantabrian Mountains is generally predominated by beeches ( Fagus sylvatica ). The Pyrenean ibex ( Capra pyrenaica pyrenaica ), one of the four subspecies of the Iberian ibex ( Capra pyrenaica ), which used to inhabit the Cantabrian Mountains, became extinct in 2000. The Cantabrian mountain range includes several protected areas such as the Picos de Europa National Park, which is one of several Cantabrian parks included in UNESCO 's World Network of Biosphere Reserves . Some of

420-808: The Cantabrian Sea, as far as the Pass of Leitariegos, also extending south between León and Galicia. The range's western boundary is marked by the valley of the river Minho ( Spanish : Miño ), by the lower Sil , which flows into the Miño, and by the Cabrera River , a small tributary of the Sil. The Cantabrian Mountains reach their south-western limit in Portugal. As a whole, the Cantabrian Mountains are remarkable for their intricate ramifications, but almost everywhere, and especially in

448-585: The United Kingdom. Upper Cretaceous cyclic sequences in Germany and marl– opal -rich Tortonian - Messinian strata in the Sorbas Basin related to multiple sea drawdown have been correlated with Milankovitch orbital forcing. Marl as lacustrine sediment is common in post- glacial lake -bed sediments. Chara , a macroalga also known as stonewort, thrives in shallow lakes with high pH and alkalinity , where its stems and fruiting bodies become calcified. After

476-478: The alga dies, the calcified stems and fruiting bodies break down into fine carbonate particles that mingle with silt and clay to produce marl. Marl ponds of the northeastern United States are often kettle ponds in areas of limestone bedrock that become poor in nutrients ( oligotrophic ) due to precipitation of essential phosphate . Normal pond life is unable to survive, and skeletons of freshwater molluscs such as Sphaerium and Planorbis accumulate as part of

504-594: The bottom marl. In Hungary, Buda Marl is found that was formed in the Upper Eocene era. It lies between layers of rock and soil and may be defined it as both "weak rock and strong soil." Marl is the dominant rock type in the Vaca Muerta Formation in Argentina. Marl has been used as a soil conditioner and neutralizing agent for acid soil and in the manufacture of Portland cement . Because some marls have

532-455: The east, it is possible to distinguish two principal ranges, from which the lesser ridges and mountain masses radiate. One range, or series of ranges, closely follows the outline of the coast; the other, which is loftier, forms the northern limit of the great tableland of Castile and León , and is sometimes regarded as a continuation of the Pyrenees. In some parts the coastal range rises sheer above

560-438: The manufacture of cement . Marl or marlstone is a carbonate -rich mud or mudstone which contains variable amounts of clays and silt . The term was originally loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay and calcium carbonate , formed under freshwater conditions. These typically contain 35–65% clay and 65–35% carbonate. The term

588-497: The north, from the dry central plateau . The north facing slopes receive heavy cyclonic rainfall from the Cantabrian Sea, whereas the southern slopes are in rain shadow . The Cantabrian Range has three very distinct sections from west to east: The Asturian Massif and its foothills. Geologically it is an eastern prolongation of the Galician Massif with Paleozoic folds. It is cut by deep east-west oriented canyons such as

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616-542: The sea, and everywhere has so abrupt a declivity that the streams which flow seaward are all short and swift. The descent from the southern range to the high plateaux of Castile is more gradual, and several large rivers, notably the Ebro , rise here and flow to the south or west. The breadth of the Cantabrian chain, with all its ramifications, increases from about 60 mi (97 km); in the east to about 115 miles (185 km) in

644-521: The sites are included in the European Union 's Natura 2000 network and Special Protection Areas for the Conservation of Wild Birds. Physiographic province A physiographic province is a geographic region with a characteristic geomorphology , and often specific subsurface rock type or structural elements. The continents are subdivided into various physiographic provinces, each having

672-798: The soil. Some marl beds have a very low permeability and are under consideration for use in the storage of nuclear waste . One such proposed storage site is the Wellenberg in central Switzerland. A marl lake is a lake whose bottom sediments include large deposits of marl. They are most often found in areas of recent glaciation and are characterized by alkaline water, rich in dissolved calcium carbonate, from which carbonate minerals are deposited. Marl lakes have frequently been dredged or mined for marl, often used for manufacturing Portland cement . However, they are regarded as ecologically important, and are vulnerable to damage by silting , nutrient pollution , drainage , and invasive species . In Britain, only

700-453: The southern United States, where soils were generally poor in nutrients, prior to about 1840. By the late 19th century, marl was being mined on an industrial scale in New Jersey and was increasingly being used on a more scientific basis, with marl being classified by grade and the state geological survey publishing detailed chemical analyses. Marl continues to be used for agriculture into

728-415: The west. Many peaks are over 6,000 feet (1,800 m) high, but the greatest altitudes are attained in the central ridges on the borders of León , Asturias , Palencia and Cantabria . Here are the highest peak Torre de Cerredo (8,688 feet (2,648 m)), Peña Vieja (8,579 feet (2,615 m)), Peña Prieta (8,304 feet (2,531 m)) and Espigüete (7,898 feet (2,407 m)); an unnamed summit in

756-419: Was chosen because of its very low permeability, absence of chert , and lack of fissures found in overlying formations. The underlying Glauconitic Marl is easily recognizable in core samples and helped establish the right level for excavating the tunnel. Marl soil has poor engineering properties, particularly when alternately wetted and dried. The soils can be stabilized by adding pozzolan ( volcanic ash ) to

784-638: Was used sporadically in Britain beginning in prehistoric times and its use was mentioned by Pliny the Elder in the 1st century. Its more widespread use from the 16th century on contributed to the early modern agricultural revolution. However, the lack of a high-energy economy hindered its large-scale use until the Industrial Revolution . Marl was used extensively in Britain, particularly in Lancashire , during

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