174 
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 
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 laminas 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 
laminas is about 30° ; but in the cliffs of Bawdesey, to the 
eastward, they are sometimes inclined at an angle of 45°, and 
even more. 
Section at the lighthouse near Happisborough. Height sixteen feet. 
a, Pebbles of chalk flint, and of rolled pieces of white chalk. 
b, Loam overlying a. c , c, Blue and brown clay. 
