FORMATIONS ABOVE THE CHALK. 



251 



strata of which these hills are composed, dip generally from 15° to 5° to 

 the south; the inchnation varying in different places. The south side of 

 the basin must therefore have been extremely steep, vs^hile the slope of the 

 north side was very gentle. The western margin cannot be distinctly 

 traced, and the eastern is now entirely destroyed, the sea flowing through 

 the opening*. 



The strata contained in the Hampshire or Isle of Wight basin, form 

 five principal divisions, viz. 



1 . Lowest marine formation over the chalk, including the plastic clay 

 and sand, together with the London clay. 



2. Lowest fresh water formation. 



3. Upper marine formation. 



4. Upper fresh water formation. 



5. Alluvium. 



The annexed sketch will illustrate this description, and shew the con- 

 nexion between the outlying fragments of these beds in Sussex, and those 

 of the Isle of Wight. 



The remains of the tertiary formations that occur in Sussex, admit of 

 the following arrangement; it must however be remarked, that from the 

 ruin and displacement to which they have been exposed, it is scarcely 

 possible in every instance accurately to determine their geological positions. 



1. Druid sandstone. 



Tertiary Formations in Sussex. 



C Boulders of siliceous sandstone, some-"' 

 * times enveloping pebbles, and forming { 

 \ a breccia resembling that of Hertford- ( 

 ' shire. 



' Scattered over the surface 

 ■ of the Downs, near Falmer, 

 I Brighton, Lewes, &c. 



* Mr, Webster on the Strata overlaying the Chalk. Geolog. Trans. Vol.ii. p. 170, et seq. 



K K 2 



