Also 5, 7–8 lyas. [Introduced into mod. geology from dialects; a. OF. liois (mod.F. liais) a compact kind of limestone.]
1. A blue limestone rock occurring in certain south-western counties of England. Also attrib.
1404. Durham Acc. Rolls (Surtees), 397. In custodia vitrarii ij par petrarum ex officio et j par vocat. lyas.
1649. Glanvill, in Phil. Trans., IV. 978. A sort of hard stone, commonly call’d a Lyas, blue and white, polishable.
1778. Eng. Gazetteer (ed. 2), s.v. Launsdon, Som., On the N.W. side of this plain are dug a sort of head-stones, called lyas, which are blue and white, and polishable.
1793. Smeaton, Edystone L., § 202, note. Lyas is the general term for strata of stone of the species of Aberthaw, in several counties.
1813. Vancouver, Agric. Devon, 27. A stratum of blue lais [sic] limestone.
1832. De la Beche, Geol. Man. (ed. 2), 155. On the coast of the S.W. part of Somersetshire … a high shingle beach, principally composed of lias (the rock of the vicinity).
1881. Young, Every Man his own Mechanic, § 1154. Blue lias lime is charged 24/- per yard.
2. Geol. A series of strata forming the lower division of the Jurassic series, consisting of thin layers of blue argillaceous limestone, and containing a great wealth of fossils.
1833. Lyell, Princ. Geol., III. Gloss, 72. Lias, a provincial name adopted in scientific language for a particular kind of limestone. Ibid. (1833), Elem. Geol. (1865), 415. The name of Gryphite limestone has sonetimes been applied to the lias.
1873. Burton, Hist. Scot., I. iii. 82. The lias, oolite, and other recent formations.
