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CHAPTER VIII. 
GEEAT OOLITE SERIES. 
(BATHONIAN.) 
THE term Great Oolite was used in 1812 by William Smith, 
being applied to the Bath stone which locally is so much more 
important than the Inferior Oolite. At one time the term 
Superior Oolite was employed in contradistinction from Inferior 
Oolite, but the term was used in so comprehensive a sense that 
even the Portland Oolite was included.* The name Upper 
Oolite has also been applied to the Great Oolite, but was similarly 
liable to mislead ; hence the term Great or Bath Oolite came into 
general use, while the more comprehensive name Bathonian was 
introduced by D'Omalius d'Halloy in 1843.f 
As our knowledge of the strata increased, other local divisions 
came to be included ; and probably owing to the difficulty of dis- 
tinguishing the equivalents of Great and Inferior Oolite in York- 
shire, John Phillips in 1829 unfortunately used the term " Bath 
oolite formation " for all the strata from the Cornbrash to the 
Inferior Oolite, inclusive. Later on it became customary to 
restrict the term to the beds above the Inferior Oolite, sometimes 
including the Fuller's Earth, and usually including the Cornbrash. 
In this comprehensive sense it is best to adopt the term Great 
Oolite Series, and group the beds as follows : 
^ fCornbrasb.. Zone of Ammonites macroceplialus. 
5 Forest Marble and "I Great Oolite Clay. ~\ 
-C<L Br fnTl Cla ^ -f Gr f t0oliteLime - I Zone of 
g g \ Great Oolite and -J stone. } . , .. 
| OD I Stonesfield Slate - \ Upper Estuarine | Am ' H*****' 
O ^Fuller's Earth - j Series. 
GREAT OOLITE SERIES. 
1. DORSETSHIRE TO OXFORDSHIRE. 
FULLOXIAN OR FuLLER*S EARTH CLAY AND ROCK. 
GENERAL ACCOUNT OF THE STRATA. 
The term Fuller's Earth was applied in 1799, by William 
Smith, to certain marls and clays, near Bath, that yield an 
important bed of economic fuller's earth. These clays directly 
overlie the Inferior Oolite and underlie the Great Oolite. 
From a geological point of view the term is an unfortunate 
one, for important beds of fuller's earth occur also in the Lower 
* See Townsend, Character of Moses, p. 105 ; and Sowerby, Mineral Conchology, 
vol. ii., 1818. 
t Attale Riche, jtude Strat. Jurassique Inf. du Jura Meridional, 1893, p. 125. 
The name Bathian has been used by Mayer-Eymar. 
