Bathonian Series

Bathonian Series refers to a series of rock strata dating from the Bathonian epoch of the Middle Jurassic.

The typical Bathonian Series is the Great Oolite series of England, and the name was derived from the "Bath Oolite", extensively mined and quarried in the vicinity of that city, where the principal strata were first studied by William Smith. 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 northwest and southwest oolite limestones are characteristically associated with coral-bearing, crinoidal and other varieties, and with certain beds of clay. In the north and northeast, Russia, etc, clays, sandstones and ferruginous oolites prevail, some of the last being exploited for iron. They occur also in the extreme north of North America and in the Arctic regions, Greenland, Franz Josef Land, etc; in Africa, Algeria, Tanzania, Madagascar and near the Cape of Good Hope (Enon Beds); in India, Rajputana and Gulf of Kutch, and in South America.

The well-known Caen stone of Normandy and "Hauptrogenstein" of Swabia, as well as the "Eisenkalk" of northwest Germany, and "Klaus-Schichten" of the Austrian Alps, are of Bathonian age.

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