Ch. XXII.] RECAPITULATION. 323 



16. The movements which threw the chalk and the tertiary 

 strata of the isles of Wight and Purbeck into a vertical posi- 

 tion, were subsequent to the formation of the Eocene fresh- 

 water strata of the Isle of Wight, but may possibly have 

 occurred during the Eocene period. 



17. The masses of secondary rock which have been removed 

 by denudation from the central axis of the Weald would, if 

 restored, rise to more than double the height now attained by 

 any patches of tertiary strata in England. 



18. If, therefore, the Eocene strata do not appear to occupy 

 a much lower level than the secondary rocks, from the destruc- 

 tion of which they have been formed, it is because the highest 

 summits of the latter have been cut off during the rise of the 

 land, and thrown into those troughs where we now find the 

 tertiary deposits. 



19. The upheaving of the strata of the London and Hamp- 

 shire basins may have been in great part effected towards the 

 close of the Eocene period ; but it must also have been in some 

 part due to the movements which raised the crag. 



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