lias
(ˈlaɪəs)
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] lime⁓stone. 1832 H. T. 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. 1833 ― Elem. Geol. (1865) 415 The name of Gryphite limestone has sometimes been applied to the lias. 1873 Burton Hist. Scot. I. iii. 82 The lias, oolite, and other recent formations. |