Marl (redirected from marliest)

Marl, city, Germany

Marl (märl), city (1994 pop. 92,590), North Rhine–Westphalia, W Germany. It is an industrial and mining (coal, lead, and zinc) center, and also supports a number of chemical factories. Now a modern city, Marl was first mentioned in the 9th cent. and was chartered in 1936.

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marl, type of soil

marl or bog lime, soil, essentially clay mixed with carbonate of lime, highly valued as a dressing or fertilizer. It crumbles rapidly and easily. Marl in which the lime is in the form of invertebrate shells is called shell marl. The term is loosely used for a variety of soils, some of which are low in lime content, e.g., the greensand marl of New Jersey. Marling of soil tends to lighten it, correct acidity, and promote nitrification.

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marl

Earthy mixture of fine-grained minerals, which range widely in composition. Lime (calcium carbonate) is present as shell fragments of snails and bivalves, or as powder mixed with clay and silica-containing silt. Large deposits contain 80–90% calcium carbonate and less than 3% magnesium carbonate. With decreasing amounts of lime, calcium-containing marls are called clays and clayey limestones. Marls rich in potash (potassium carbonate), called greensand marls, are used as water softeners. Marls have also been used in the manufacture of insulating material and portland cement, as liming material, and in making bricks.

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marl

a fine-grained sedimentary rock consisting of clay minerals, calcite or aragonite, and silt: used as a fertilizer

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marl [märl]

(geology)

A deposit of crumbling earthy material composed principally of clay with magnesium and calcium carbonate; used as a ertilizer for lime-deficient soils. Also known as malm.

(textiles)

Two yarns of different colors or kinds twisted around each other.

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marl

An earthy deposit; a mixture of clay and carbonate of lime.

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Marl 

a city in the Federal Republic of Germany in the Land of North Rhine-Westphalia, in the Ruhr. Population, 77,000 (1970). Marl is an important center for the production of synthetic rubber, plastics, synthetic resins, chemical fibers, soda, and chlorine. Coal and lead and zinc ores are mined in the area.

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Marl 

a sedimentary rock composed of calcite or dolomite and clay minerals. The ratio of carbonaceous to clay components may vary. Generally marl is identified as rock containing from 30 to 90 percent CaCO³ or MgCO³ and, correspondingly, from 70 to 10 percent clay particles. There are clay, calcareous, chalky, and dolomite marls and, depending on admixtures, there are siliceous, glauconite, sandy, micaceous, bituminous, and carbonaceous marls. Color varies, most often being light. Marl is widespread in nature and is found in all systems beginning with the Proterozoic. In the USSR marl is universally developed in carbonaceous and clay strata. It is used as a raw material in the production of certain kinds of cement. Natural cement marl containing 75–80 percent CaCOa is the most important. In the USSR the most well-known deposits of cement marl are in the vicinity of Novorossiisk, Amvrosievka (Donetsk Oblast), and the village of Podgornoe (Voronezh Oblast).

Marl deposits are worked by open-cut mining. Processing is done in powerful rotary furnaces working on mixtures of different types of marl and chalk.

G. I. BUSHINSKII