The bulk of the evidence is in favour of the laccolitic theory; in fact it has been clearly demonstrated in many important cases. Still it is equally clear that many granites are not merely passive injections, but have assimilated much foreign rock. Possibly much depends on the chemical composition of the respective masses, and on the depths and temperatures at which the intrusion took place. Increase of pressure and of temperature, which we know to take place at great depths, would stimulate resorption of sedimentary material, and by retarding cooling would allow time for dissolved foreign substances to diffuse widely through the magma. (J. S. F.)
BATHONIAN SERIES, in geology. The typical Bathonian is the Great Oolite series of England, and the name was derived from the "Bath Oolite," so extensively mined and quarried in the vicinity of that city, where the principal strata were first studied by W. Smith. The term was first used by J. d'Omalius d'Halloy in 1843 (_Precis Geol_.) as a synonym for "Dogger"; but it was limited in 1849 by A. d'Orbigny (_Pal. Franc. Jur_. i. p. 607). In 1864 Mayer-Eymar (_Tabl. Synchron_.) used the word "Bathien" = Bajocian + Bathonian (sen. str.). According to English practice, the Bathonian includes the following formations in descending order: Cornbrash, Forest Marble with Bradford Clay, Great or Bath Oolite, Stonesfield Slate and Fullers' Earth. (The Fullers' Earth is sometimes regarded as constituting a separate stage, the "Fullonian.") The "Bathonien" of some French geologists differs from the English Bathonian in that it includes at the base the zone of the ammonite _Parkinsonia Parkinsoni_, which in England is placed at the summit of the Inferior Oolite. The Bathonian is the equivalent of the upper part of the "Dogger" (Middle Jurassic) of Germany, or to the base of the Upper Brown Jura (substage "E" of Quenstedt).
Rocks of Bathonian age are well developed in Europe: in the N.W. and S.W. oolite limestones are characteristically associated with coral-bearing, crinoidal and other varieties, and with certain beds of clay. In the N. and N.E., Russia, &c., clays, sandstones and ferruginous oolites prevail, some of the last being exploited for iron. They occur also in the extreme north of America and in the Arctic regions, Greenland, Franz Josef Land, &c.; in Africa, Algeria, German East Africa, Madagascar and near the Cape (Enon Beds); in India, Rajputana and Gulf of Cutch, and in South America.