Marl

a lime-enriched clay, or sand. Marl owes its peculiar character to the disintegration of innumerable shells of small mollusks. Marl is exceedingly mellow. It is used to dress lands lacking in fertility. It is used also in the making of Portland cement. The most noted American deposits are found on the Atlantic coast, but marl may be found at the bottom of ancient swamps, almost anywhere. Marl impregnated with phosphorus is known to the gardener as phosphate. Marls and phosphates are important articles of shipment from Savannah and other South Atlantic cities. The potato raiser of the Aroostook valley, Maine, drops a handful of phosphate in each hill. See Lime; Phosphorus