390 LOWER OOLITIC ROCKS OF ENGLAND : 
Thornton. (See p. 378.) Hard white and shelly limestones form 
the top portion "of the "Great Oolite, while lower down there are 
alternations of brown limestone and sandstone, the observed 
thickness at Thornton being a little over 12 feet.* 
The occurrence in this area of thin layers of sandstone alter- 
nating with the limestones is of interest. Such sandy beds, as a 
rule, characterize the Lower Division of the Great Oolite, and 
more especially the Stonesfield Series in Gloucestershire and 
Oxfordshire. Prof. Green observed " beds of flaggy sandstone, 
plentifully marked by the tracks and sandy excrement of worms," 
in the quarries at Cosgrove.f 
A quarry west of Deanshanger showed the following section : 
FT. IN. 
("Fissile oolitic limestone and rubble -~| 
1 Marly bed and greenish clay, with [ 
Ostrea - - - - > 6 
Great Oolite J White fossiliferous marly beds, the top | 
Limestone. *, layer more or less oolitic - -J 
Current-bedded gritty limestone 8 to 1 
I Fissile marly beds - - 2 6 
(^Oolitic limestones - - 3 6 
These beds may be compared with those of Akeley Barn and 
Lillingston Lovell ; and they occur in the upper part of the Great 
Oolite Limestone. 
More important sections were shown in the quarries and brick- 
yard at Deanshanger, where I noted the following sequence of 
beds : 
FT. In. 
fRubbly beds. 
'l Impure and oolitic limestones and seams 
of blue clay : the former worked for 
building-stone - - 8 to 10 
Great Oolite * * * * 
Limestone. 
Shelly bed, with Echinoderms (Clypeus 
Mulleri) and Gasteropoda - 1 G 
Rotten marly and earthy beds - 2 8 
Clayey bed - - - - 6 
AVhitish marly stone - - 3 6 
Blue clay, with Ostrea and thin calca- 
reous stone - - - 3 
Upper Estuarine JST^ui tiT ' j " i, T ." 
Series 1 Stiff blue, black, and greenish clay, with 
lignite (and bones, according to work- 
men) 3 ft. 6 in. seen. Said to be 18 
[_ feet altogether - - - 18 
Lower Eetuarine "1 -rrruv c j / u- \ 
Series. | White Sand (yielding water). 
The clay is said to get white and sandy towards the base. The dark 
clays burn to a white brick, and the greenish clay barns to a red brick. 
Clay for the old potteries of Potterspury, was obtained in Cosgrove 
Field ; but the works have long been closed.^ 
* Geol. Banbury, p. 28. 
t These and subsequent notes by Prof. Green on the country near Stony Stratford 
aud Newport Pagnell, are from his MSS., prspared for the Explanation of Sheet 46 
N.W. of the Geological Survey Map. 
$ Morton, Nat. Hist. Northants, 1712, p. 72. 
