S. W. England and Midlands. | Yorkshire. | Ammonite Zones.* | Divisions according to A. de Lapparent.** | ||
Upper Lias. |
Midford Sands (passage beds) | Alum shale | Am. jurensis | U. | (Including the opalinus zone of the Inferior Oolite.) |
Clays with Cement-stones | Jet Rock | Am. communis | Toarcien. | ||
Limestones and Clays | Grey Shale | Am. serpentinus | |||
Am. annulatus | M. | ||||
Middle Lias. |
Marlstone and Sands (Rock Bed and Ironstones) |
Ironstone Series | Am. spinatus | Charmouthien. | |
Micaceous Clays and Sands | Sandy Series | Am. margaritatus | |||
Lower Lias. |
Clays with occasional bands of Limestone |
Upper Series with Ironstone nodules |
Am. capricornus Am. Jamesoni and Am. armatus | ||
Limestones and Clays | Lower Series with Sandy and Marly Beds |
Am. oxynotus Am. Bucklandi Am. angulatus Am. planorbis |
L. | Sinémourien. Hettangien including “White Lias.” | |
Rhétien. |
** Traité de géologie (5th ed., Paris, 1906).
The economic products of the Lias are of considerable importance. In the Lower Lias of Lincolnshire and the Middle Lias of Oxfordshire, Northamptonshire, Lincolnshire, Leicestershire and Yorkshire the beds of ironstone are of great value. Most of these ores are limestones that have been converted into iron carbonate with some admixture of silicates; they weather near the surface into hydrated peroxide. At Frodingham in Lincolnshire the oolitic iron ore reaches 30 ft. in thickness, of which 12 ft. are workable. In Gloucestershire the top beds of the Lower Lias and lower beds of the Middle division are the most ferruginous; the best ores near Woodstock and Banbury and between Market Harborough and Leicester are at the summit of the Middle Lias in the Marlstone or Rock bed. The ironstone of Fawler is sometimes known as Blenheim ore. The ores of the Cleveland district in Yorkshire have a great reputation; the main seam is 11 ft. thick at Eston, where it rests directly upon the Pecten Seam, the two together aggregating 15 ft. 6 in. Similar iron ores of this age are worked at Meurthe-et-Moselle, Villerupt, Marbache, Longuy, Champagneulles, &c. Some of the Liassic limestones are used as building stones, the more important ones being the Lower Lias Sutton stone of Glamorganshire and Middle Lias Hornton stone, the best of the Lias building stones, from Edge Hill. The limestones are often used for paving. The limestones of the Lower Lias are much used for the production of hydraulic cement and “Blue Lias” lime at Rugby, Barrow-on-Soar, Barnstone, Lyme Regis, Abertham and many other places. Roman cement has been made from the nodules in the Upper Lias of Yorkshire; alum is obtained from the same horizon. A considerable trade was formerly done in jet, the best quality being obtained from the “Serpentinus” beds, but “bastard” or soft jet is found in many of the other strata in the Yorkshire Lias. Both Lower and Upper Lias clays have been used in making bricks and tiles.
Fossils are abundant in the Lias; Lyme Regis, Shepton Mallet, Rugby, Robin Hood’s Bay, Ilminster, Whitby and Golden Cap near Charmouth are well-known localities. The saurian reptiles, Ichthyosaurus and Plesiosaurus, are found in excellent preservation along with the Pterodactyl. Among the fishes are Hybodus, Dapedius, Pholidophorus, Acrodus. The crinoids, Pentacrinus and Extracrinus are locally abundant. Insect remains are very abundant in certain beds. Many ammonites occur in this formation in addition to the forms used as zonal indexes mentioned in the table. Lima gigantea, Posidonomya Bronni, Inoceramus dubius, Gryphaea cymbium and G. arcuata are common pelecypods. Amberleya capitanea, Pleurotomaria anglica are Lias gasteropods. Leptaena, Spiriferina, Terebratella and Rhynchonella tetrahedra and R. variabilis are among the brachiopods.
Certain dark limestones with regular bedding which occur in the Carboniferous System are sometimes called “Black Lias” by quarrymen.
See “The Lias of England and Wales” (Yorkshire excepted), by H. B. Woodward, Geol. Survey Memoir (London, 1893); and, for Yorkshire, “The Jurassic Rocks of Britain,” vol. i., “Yorkshire,” by C. Fox-Strangways, Geol. Survey Memoir. See also Jurassic. (J. A. H.)
LIBANIUS (A.D. 314–393), Greek sophist and rhetorician,
was born at Antioch, the capital of Syria. He studied at Athens,
and spent most of his earlier manhood in Constantinople and
Nicomedia. His private classes at Constantinople were much
more popular than those of the public professors, who had him
expelled in 346 (or earlier) on the charge of studying magic.
He removed his school to Nicomedia, where he remained five
years. After another attempt to settle in Constantinople, he
finally retired to Antioch (354). Though a pagan, he enjoyed
the favour of the Christian emperors. When Julian, his special
patron, restored paganism as the state religion, Libanius showed
no intolerance. Among his pupils he numbered John Chrysostom,
Basil (bishop of Caesarea) and Ammianus Marcellinus.
His works, consisting chiefly of orations (including his autobiography),
declamations on set topics, letters, life of Demosthenes,
and arguments to all his orations are voluminous. He devoted
much time to the classical Greek writers, and had a thorough
contempt for Rome and all things Roman. His speeches and
letters throw considerable light on the political and literary
history of the age. The letters number 1607 in the Greek
original; with these were formerly included some 400 in Latin,
purporting to be a translation, but now proved to be a forgery
by the Italian humanist F. Zambeccari (15th century).
Editions: Orations and declamations, J. J. Reiske (1791–1797); letters, J. C. Wolf (1738); two additional declamations, R. Förster (Hermes, ix. 22, xii. 217), who in 1903 began the publication of a complete edition; Apologia Socratis, Y. H. Rogge (1891). See also E. Monnier, Histoire de Libanius (1866); L. Petit, Essai sur la vie et la correspondance du sophiste Libanius (1866); G. R. Sievers, Das Leben des Libanius (1868); R. Förster, F. Zambeccari und die Briefe des Libanius (1878). Some letters from the emperor Julian to Libanius will be found in R. Hercher, Epistolographi Graeci (1873). Sixteen letters to Julian have been translated by J. Duncombe (The Works of the Emperor Julian, i. 303–332, 3rd ed., London, 1798). The oration on the emperor Julian is translated by C. W. King (in Bohn’s “Classical Library,” London, 1888), and that in Defence of the Temples of the Heathen by Dr Lardner (in a volume of translations by Thomas Taylor, from Celsus and others, 1830). See further J. E. Sandys, Hist. of Classical Scholarship, i. (1906), and A. Harrent, Les Écoles d’Antioche (1898).
LIBATION (Lat. libatio, from libare, to take a portion of
something, to taste, hence to pour out as an offering to a deity,
&c.; cf. Gr. λείβειν), a drink offering, the pouring out of a
small quantity of wine, milk or other liquid as a ceremonial act.
Such an act was performed in honour of the dead (Gr. χοαί, Lat.
profusiones), in making of treaties (Gr. σπονδή, σπένδειν = libare,
whence σπονδαί, treaty), and particularly in honour of the gods
(Gr. λοιβή, Lat. libatio, libamentum, libamen). Such libations to
the gods were made as part of the daily ritual of domestic worship,
or at banquets or feasts to the Lares, or to special deities, as by
the Greeks to Hermes, the god of sleep, when going to rest.
LIBAU (Lettish, Leepaya), a seaport of Russia, in the government
of Courland, 145 m. by rail S.W. of Riga, at the northern
extremity of a narrow sandy peninsula which separates Lake
Libau (12 m. long and 2 m. wide) from the Baltic Sea. Its
population has more than doubled since 1881 (30,000), being
64,505 in 1897. The town is well built of stone, with good
gardens, and has a naval cathedral (1903). The harbour was