ITS- OLDER PLIOCENE PERIOD. 



[Ch.XIII. 



direction of the strata, and the crag affords most interesting 

 illustrations of this phenomenon. 



In the sea-cliff near Walton, in Suffolk, opposite the Mar- 

 tello Tower, called R, the section represented in the annexed 

 diagram is seen. The vertical height is about 20 feet, and 



No. 31. 



Section of shelly crag near Walton, Suffolk. 



the beds consist alternately of sets of inclined and horizontal 

 layers of sand and comminuted shells. The sand is siliceous 

 and of a ferruginous colour, but the layers are sometimes made 

 up of small plates of bivalve shells, arranged with their flat 

 sides parallel to the plane of each layer, like mica in micaceous 

 sandstones. 



The number of laminae in the thickness of an inch, both in 

 the siliceous and shelly sand, varies from seven to ten in num- 

 ber, so that it is impossible to express them all in the diagram. 

 The height of the uppermost stratum is, in this instance, re- 

 markable, as it extends to twelve feet. The inclination of the 

 lamina? is about 30 ; but in the cliffs of Bawdesey, to the 

 eastward, they are sometimes inclined at an angle of 45, and 

 even more. 



No. 32. 



Xectlm nl (lie U^lithitnse near Ilappislorougli. Height sixteen feet. 



a, Pebbles of chalk Hint, and of rolled pieces of while clmlk. 



b, Loam overlying <i. c, c, Blue and brown clay. 



