GREAT OOLITE CLAY. 
885 
shire and Lincolnshire, these beds of clay again thicken, and 
become of greater importance." Here and there, as at Stowe- 
nine-Churches, there are bands of limestone that present the 
characters of Forest Marble. Nevertheless in several areas, as 
near Oundle, the Great Oolite Clay was too thin and insignificant 
in its outcrop, to be separately shown on the Geological Survey 
Map. 
LIST OF FOSSILS FROM THE GREAT OOLITE CLAY. 
Cetiosaurus. 
Fish-remains. 
Gervillia. 
Modiola. 
Ostrea gregaria. 
Sowerbyi. 
subrugulo&a. 
Placunopsia socialis. 
Perna. 
Trigonia. 
Rhynchonella concinna. 
Terebratula. 
Serpula. 
Foraminifera. 
FIG. 110. 
Ostrea subrugulosa, Mor. and Lye., x 1|. 
LOCAL DETAILS. 
Ayiiho to Br&cliley and Buckingham. 
In the country from Aynho to Towcester it is difficult to make 
any satisfactory divisions in the Great Oolite, for I know of no 
continuous section of the strata ; the Upper Estuarine Series and 
the Great Oolite Clay are not often exposed, and the Great 
Oolite Limestone is shown only in shallow quarries. 
Here and there we may recognize at the base of the formation 
fissile and sandy beds, suggestive of the Stonesfield Slate (I.), but 
no definite correlation can be made ; and these beds rest on blue 
clay, that may be equivalent to the Fullonian Clay seen near 
Chipping Norton, but is (in the area to be described) more 
conveniently grouped with the Upper Estuarine Series. 
Broadly speaking the beds may be divided as follows : 
Great Oolite 
Clay. 
Great Oolite 
Limestone. 
Upper Estuarine 
Series. 
E 75928. 
}day. 
fll. White limestones and occasional 
| oolitic and shelly limestones, sandy 
beds, and layers of marl and greenish 
^ and dark clay ; with Nerinaea, Ostrea, 
Trigonia, Pholadomya, and Corals 12 to 
I I. Fissile and false-bedded oolite and 
layers of marl ; Clypeut Mulltri - 
25 
Dark blue cl& y 
- 10 
1 6 to 5 
& B 
