- marl
-
marl1
/mahrl/, n.1. Geol. a friable earthy deposit consisting of clay and calcium carbonate, used esp. as a fertilizer for soils deficient in lime.2. Archaic. earth.v.t.3. to fertilize with marl.[1325-75; ME marle < MD < OF < ML margila, dim. of L marga, said to be < Gaulish]marl2/mahrl/, v.t. Naut.to wind (a rope) with marline, every turn being secured by a hitch.[1400-50; late ME marlyn to ensnare; akin to OE marels cable. See MOOR2]
* * *
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.* * *
▪ Germanycity, North Rhine–Westphalia Land (state), western Germany. It is situated in the Ruhr industrial district, just northwest of Recklinghausen. First mentioned about 800 as a relatively large settlement, the Marl district was sold to the archbishops of Cologne about 1000 and thereafter was part of the “Vest Recklinghausen” of the prince electors. After 1802 it passed to the dukes of Arenberg, who held it as a fief of Prussia from 1815. It grew with the development of coal and iron ore mining in the late 19th century, and the town was chartered in 1936. Chemical factories and heavy industry traditionally supplemented coal mining, but these declined in the late 20th century. Pop. (2003 est.) 91,748.* * *
Universalium. 2010.
