ROOM 1IT. 



GEOLOGICAL MUTATIONS. 



217 



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J S 



i 



tunnel on the railroad,) and across 

 the intervening region composed of 

 the sediments of a delta of incalculable 

 antiquity. 1 



GEOLOGICAL MUTATIONS. The pre- 

 sent distribution of the strata, as shown 

 by the preceding observations, appears 

 to admit of the following explanation. 

 Assuming the original deposition of 

 the strata to have been horizontal, and 

 in the sequence above pointed out, the 

 Wealden resting on the Oolite, the 

 Chalk on the Wealden, and the Ter- 

 tiary on the Chalk the whole surface 

 of the country must have originally 

 consisted of the same Tertiary strata 

 as those of London and its vicinity. 

 If by a force acting from beneath, 

 in the direction of the arrow, A, 

 Lign. 47, the entire series were broken 

 through, the chalk with the super- 

 incumbent tertiary strata would be 

 thrown into highly inclined positions 

 towards the north and south ; and if a 

 similar disturbance took place along the 

 area occupied by the British Channel, 

 England would be separated from the 

 Continent, and the small portion, now 

 the Isle of Wight, be forced into its 

 present position, by a subsidence in 

 the direction of the arrow, B, Lign. 

 47, along the course of the present 

 bed of the Solent Sea. The actual 

 position of the strata, could our obser- 

 vations extend to a sufficient depth, 

 would probably present the section 

 sketched in Lign. 47, which is in 

 accordance with the local phenomena 

 observable in the Isle of Wight, and 

 other places introduced in the diagram. 



See Geological Excursion in " Medals of Creation," voL ii. p. 908. 



