The Collaborative International Dictionary
Argillaceous sandstone
Argillaceous \Ar`gil*la"ceous\, a. [L. argillaceus, fr. argilla.] Of the nature of clay; consisting of, or containing, argil or clay; clayey.
Argillaceous sandstone (Geol.), a sandstone containing much clay.
Argillaceous iron ore, the clay ironstone.
Argillaceous schist or state. See Argillite.