468 H. B. Woodward—Notes on Jurassic Rocks. 
furnished by the persistence of the Bradford Clay is opposed to the 
view that the Great Oolite is replaced in any way by the Forest 
Marble. 
In Oxfordshire and Gloucestershire the Great Oolite and the 
Stonesfield Slate merge downwards into the Fuller’s-earth with no 
marked stratigraphical division, and this is the case as far as 
Lansdown, near Bath. Northwards the Fuller’s-earth is much 
attenuated, and near Chipping Norton it rests on a higher stage of 
the Inferior Oolite than we find in the Cotteswold Hills, as if in the 
former area the conditions attending the deposition of Inferior 
Oolite lingered longer. Rarely do we find any interblending of 
Inferior Oolite and Fuller’s-earth ; indeed, we sometimes find 
indications of local pauses in deposition, marked by annelide burrows, 
etc. So that on stratigraphical grounds the Fuller’s-earth is more 
intimately connected with the Great Oolite than with the Inferior 
Oolite. 
In Dorsetshire the Fuller’s-earth series attains its greatest develop- 
ment in this country, and is separable into Upper and Lower clayey 
divisions, with an intermediate bed of Fuller’s-earth Rock. These 
divisions may be traced northwards to Lansdown and Slaughterford, 
near Bath, where the Fuller’s-earth Rock is present in an attenuated 
form, and where the Upper Fuller’s-earth merges into the base of 
the Great Oolite. 
It is therefore clear that the mass of the Great Oolite is not 
represented in the Fuller’s-earth series of Dorsetshire, although its 
lower beds may be partially replaced by the Upper Fuller’s-earth. 
The mass of the Great Oolite, therefore, either wedges out abruptly 
south of Bradford-on-Avon, or has been to some extent denuded. 
On the whole, it appears probable that the Great Oolite has been 
denuded—the erosion being local and contemporaneous so far as the 
Great Oolite series is concerned. The structure of the Forest Marble, 
with its clay-galls, its current-bedded limestones made up of broken 
shells and oolitic grains (the latter sometimes in a sandy matrix), 
favours the notion that it may have been largely derived from 
previous accumulations ; and this opinion was suggested by Dr. Sorby 
from a microscopical study of some of the beds. 
The organic remains of the Fuller’s-earth include many species 
common to the Inferior Oolite and many common to the Great 
Oolite. Of seventy-two species, obtained during the course of the 
Geological Survey, fifty-eight are known also in the Great Oolite and 
forty-two in the Inferior Oolite, a number being common to the two 
formations. The palzontological evidence therefore coincides with 
the stratigraphical, that the Fuller’s-earth on the whole is more 
intimately connected with the Great Oolite than with the Inferior 
Oolite. For convenience of classification it should therefore be 
placed with the Great Oolite series. 
