[ noun ] a loose and crumbling earthy deposit consisting mainly of calcite or dolomite; used as a fertilizer for soils deficient in lime <noun.substance>
Marl \Marl\, v. t. [imp. & p. p. {Marled}; p. pr. & vb. n. {Marling}.] [Cf. F. marner. See {Marl}, n.] To overspread or manure with marl; as, to marl a field.
Marl \Marl\, v. t. [See {Marline}.] (Naut.) To cover, as part of a rope, with marline, marking a pecular hitch at each turn to prevent unwinding.
{Marling spike}. (Naut.) See under {Marline}.
Marl \Marl\, n. [OF. marle, F. marne, LL. margila, dim. of L. marga marl. Originally a Celtic word, according to Pliny, xvii. 7: ``Quod genus terr[ae] Galli et Britanni margam vocant.'' [root]274.] A mixed earthy substance, consisting of carbonate of lime, clay, and sand, in very variable proportions, and accordingly designated as calcareous, clayey, or sandy. See {Greensand}.
Greensand \Green"sand`\ (-s[a^]nd`), n. (Geol.) A variety of sandstone, usually imperfectly consolidated, consisting largely of glauconite, a silicate of iron and potash of a green color, mixed with sand and a trace of phosphate of lime.
Note: [hand]Greensand is often called {marl}, because it is a useful fertilizer. The greensand beds of the American Cretaceous belong mostly to the Upper Cretaceous.
Andre Benard is French joint chairman of Eurotunnel, the Anglo-French consortium pursuing an age-old dream, the linking of Britain and France with a tunnel bored through the chalk marl beneath the English Channel.