356 Mr. Lyell oti the Boulder Formation, 



R. C. Taylor, who had opportunities of observing them at 

 low tide as being continuous with the solid bed of chalk ex- 

 tending under the sea for nearly a mile from Trimmingham 

 to Sidestrand, constituting everywhere under water a level 

 platform. He also says that the chalk of this platform con- 

 tains throughout parallel strata of flint, is harder than that of 

 Cromer or Norwich, is characterized by several peculiar fossils, 

 and occupies, he thinks, a higher place in the series than the 

 chalk at Norwich *. 



Now the platform here alluded to is evidently what the 

 sea has left after sweeping away by gradual denudation all 

 that once rose above low water, and it is therefore impossible 

 for us now to conjecture to what height the chalk thus removed 

 may once have risen. The most southern of the three protu- 

 berances before mentioned occurs near the Beacon hill, about 

 half way between Mundesley and Trimmingham, and it is in 

 contact with stratified drift the beds of which are highly in- 

 clined. The mass of chalk is about 20 feet in height, its ex- 

 tent along the beach about 100 feet, and its thickness from 

 the beach inland a few yards only. It stands up like a nar- 

 row wall, which will ultimately be destroyed, and then the 

 whole face of the cliff will consist of clay sand and gravel. 



The surface of this wall of chalk, where in contact with the 

 drift, dips inland at an angle of about 45°, and the beds of 

 the newer deposit conform to this slope. As the chalk offers 

 more resistance to the waves than the drift, a small promon- 

 tory is produced at this point, which projects about 40 feet 

 beyond the general coast line, and by aid of this promon- 

 tory we are able to see the junction of the chalk and newer 

 beds, both on the north and south side, so that the relative 

 position of the two formations is very clearly ascertained 

 (see fig. 6.) 



When I visited this spot in 1829, I found the cliff nearly 

 in the same state as it remained in 1839, and the description 

 which I gave of it in the Principles of Geology would still be 

 appropriate ■\. 



But when last there I was able to examine the entire struc- 

 ture of this cliff more thoroughly, and I was more fully con- 

 firmed in my opinion that both the chalk and incumbent for- 

 mation, for the thickness of several hundred feet, must have 

 been subject to some common movement, whether sudden or 

 gradual, by which the strata of both have been tilted. 



The annexed view of the promontory (fig. 6.) was taken 

 from a point on the sloping cliff a few hundred yards to 

 the south, where the beds have already recovered their hori- 



* Geol. Trdiis., vol. i. 2nd series, p. 376. 



t Vol. iii. 1st edit. p. J 79, or 5th edit. vol. iv. p. 85. 



