Marl (2)

Marl, n. [OF. marle, F. marne, LL. margila, dim. of L. marga marl. Originally a Celtic word, according to Pliny, xvii. 7: “Quod genus terræ Galli et Britanni margam vocant.” √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.