ISO 



OLDER PLIOCENE PEUIOIJ. [Ch. XIII. 



movements have given rise to some of the local derangements 

 in this formation, particularly where masses of solid chalk 

 pierce, as it were, the crag. Thus, between Mundesley and 

 Trimmingham we see the appearances exhibited in the accom- 

 panying view (No. 41). The chalk, of which the strata are 

 highly inclined, or vertical, projects in a promontory, because 

 it offers more resistance to the action of the waves than the 

 tertiary beds which, on both sides, constitute the whole of the 

 cliff. The height of the soft crag strata immediately above 

 the chalk is, in this place, about 130 feet. Those which are 

 in contact (see the wood-cut) are inclined at an angle of 45, 

 and appear more disturbed than in other parts of the cliffs, 

 as if they had been displaced by the movement by which the 

 chalk was protruded. 



Very similar appearances are exhibited by the northernmost 

 of the three protuberances of chalk, of which a front view is 

 given in the annexed diagram. It occupies a space of about 100 

 yards along the shore, and projects about GO yards in advance 

 of the general line of cliff. One of its edges, at c, rests upon 



No. 42. 



Northern protuberance ofchalh, Trimmingham. 



a. Chalk with flints. c. Laminated blue clay. 



b. Gravel, of broken and half-rounded flints, d. Sand and yellow loam. 



the blue clay beds of the crag, in such a manner as to imply 

 that the mass had been undermined when the crag was 

 deposited, unless we suppose, as some have done, that this 

 chalk is a great detached mass enveloped by crag. For, 



