§ 18. 



EOCENE, OR LOWER TERTIARY. 



227 



on clays, sands, and shingles, filling up a basin of cre- 

 taceous strata, the margin of which skirts the area of the 

 tertiary on the south, but leaves it open to the sea on the east. 

 In Hampshire, and on the northern part of the Isle of Wight, 

 a series of contemporaneous lacustrine beds, with inter- 



Lign. 33. — Tertiary basins of Paris, London, and Hants. 

 (From Mr. Webster's Map; Geol. Trans. Vol. II.) 



spersions of marine deposits, in like manner rests upon the 

 Chalk. The relative situation and comparative extent of 

 these three basins are shown in the map (Lign. 33) ; and 



Lign. 34.— Section from Herts, to Sens, in France. 



(From Mr. LyelVs Elements of Geology.) 



1. 1, Tertiary; 2, 2, Chalk; 3, 3, Greenland ; 4, 4, Wealden. 



The shaded sites of London and Paris, and of part of Hants and the Isle of Wight, 



indicate the tertiary deposits. 



the ideal section {Lign. 34), from Hertfordshire across the 



British Channel, to Sens in France, explains the position 



Q2 



