xi. INFERIOR OOLITE. 143 



mollusca. From 127 (or 147) feet of thickness in Leckhampton 

 Hill, this massive freestone diminishes to about 40 or 46 at 

 Turkdean near Naunton ; at Sherborne it is reduced to 5 feet ; and 

 at Stow, Bissington, and Burford it entirely disappears l . 



As a building stone, the Inferior oolite nowhere acquires such 

 importance, in respect of abundance or quality, as in the range 

 of the Cotswolds of Gloucestershire, by Painswick, Leckhampton, 

 and Broadway, and a tract of country extending south-eastward 

 as far as Naunton. Within this large area it is everywhere pro- 

 ductive of good freestone in great plenty, both of the fine-grained 

 pure oolite, equal to Bath stone for ornamental structures, and of 

 the stronger, partly shelly texture, which makes firm arch-stones, 

 coping, sills, troughs, slabs, and steps. Near Cheltenham two 

 bands of the ' freestone ' are specially noted, the lower one very 

 thick and largely quarried in Leckhampton Hill, in a range distinct 

 from the other, which is also quarried near the summit. The 

 Painswick oolite is often remarkably even in its spherical grains. 

 Beyond the district named these freestones are of small importance 

 or even absent, while the rougher beds at the top and bottom, the 

 ragstone and pea-grits, are more continuously traceable. Near Bath 

 the Inferior oolite yields but little, and that rarely any good free- 

 stone. 



The ragstone is very often burned to lime, and both it and the 

 pea-grit yield fair material for walling and road-making. The 

 action of the weather, by means of rain, frost, and carbonic acid, 

 is very obvious in these and other calcareous rocks. Thus are the 

 beds broken up into small fragments, the natural joints widened, 

 and their sides penetrated; the surfaces of the -rocks pitted and 

 undulated, so as to produce in exposed situations very fantastic 

 hollows, branching ridges, and crests the Daglingworth stones are 

 an example in the Great oolite, which often shelter shell-snails, and 

 sometimes suggest the idea of these animals having made the holes 

 into which they retire. 



The surface of some hard beds has been bored by lithodomous 

 mollusks, making cylindrical holes ; an important fact, shewing the 

 slowness of the deposition of these rocks, one bed having acquired 

 solidity and remained exposed to the ravages of oceanic residents 

 before the commencement of the formation of that which succeeds. 



1 Hull in Memoirs of Geological Survey,, 185 7. 



