260 



Martinis Geological Memoir, and 



name of diluvium, as resulting from that catastrophe which so 

 greatly modified the face of our earth. It is impossible to 

 conceive any thing more strongly indicative of the tumultuous 

 action of prodigious currents than those deposits display. — 

 On the Norfolk coast, where they arrive at their greatest 

 thickness, an abundance of characteristic sections are exposed^ 

 The following {Jig, 123.) was sketched in 1824', and shows part 

 of the cliff, about 100 ft. high, west of Cromer. 



123 



We might multiply illustrations of diluvial contortions, to 

 any extent, were it essential. They consist of concentric 

 layers of sand, gravel, clay, and chalk, or of irregular beds of 

 each, and occasionally exhibit enormous boulders of chalk, and 

 fragments of rocks. At Beeston, on the same coast, may be 

 observed another singular section, whence the following sketch 

 (Jig* 124?.) is taken. In both cases, the whole reposes upon crag, 



124 



chcUk. , 



Our geologists have scarcely decided whether the ferruginous 

 sands of the eastern counties, containing the marine shells, 

 locally termed crag, should be arranged as appertaining to this 

 great diluvial deposit; some considering it as proper dilu- 

 vium, while others are inclined to view it as a distinct marine 

 formation, covered by diluvium, and reposing its southern por- 

 tion upon the London clay, and its northern immediately upon 

 the chalk. Without adverting further to that point, we sub- 



