Mr. De la Beche on the Geologij of Part of France. 79 



Sallenelles to St. Come, though hid under the dunes. It appears likewise 

 inland, between the range of Caen freestones and the low hills to the east- 

 Avard ; and at Cagny, on the road from Caen to MouU, there are quarries 

 of this rock; as also at Bonneville, two leagues from Caen on the road to 

 Troarn. 



Caen Freestones. — These beds occupy the same geological position with 

 the freestones of Bath ; they are not however oolitic, but sandy. When 

 first quarried they are friable and soft, but become harder by exposure to the 

 atmosphere. The beds are not observable on the coa.st, and from the general 

 flatness of the country the line of separation between them and the rocks above 

 and below is rather difficult to trace. The principal quarries are in the 

 neighbourhood of Caen, and along the banks of the Orne from that town to 

 Sallenelles. The freestones of Caen were, as is well known, formerly 

 much used in England. 



On the road from Caen to Bayeux the freestone beds may be traced in con- 

 tinuity as far as St. Croix : they extend, on the road from Caen to Villers, 

 nearly to Tourville*; on the road from Caen to Conde sur Noireau, to Fon- 

 tenay ; and on that from Caen to Falaise nearly to the latter town f ; for I 

 am disposed to consider the quarries at St. Pierre and Aubigny as the lower 

 of these beds. 



In that part of the department of Calvados which is principally composed 

 of these beds, older rocks frequently present themselves. The country on the 

 road from Caen to Falaise is composed of the freestone beds as far as Cin- 

 taux, where suddenly, without any difference in the level of the surface, 

 a compact siliceous sandstone rises from under them, which continues nearly 

 to Langannerie; from thence the calcareous beds continue to Potigny, where 

 a small area is again occupied by a bed of quartz rock. 



On the road from Caen to Villers argillaceous slate and quartz rock are 

 disclosed by denudation at Tourville ; and at May, on the road from Caen to 

 Conde sur Noireau, there is a denudation of a sandstone that has much the 

 appearance of old red sandstone. 



Inferior Oolite. — In the department of Calvados, the remarkable bed of 

 this rock with ferruginous grains, is accompanied, both above and beneath, 



* I am informed that they are also found to the south of the denudation at Tourville. 

 t The Caen freestones are also found beyond Falaise; but that part of the country does not 

 come within the scope of (he present comrauniration. 



