IS THE BRITISH ISLES. 



chalk, this area of denudation opens out like an ancient bay upon the English 

 Channel. Its level parts consist of clav, above which rises a central ridge composed 

 of Hastings sands.* 



Quite as striking as the contrast between the rugged mountain regions which 

 occupy North Britain and the west of England is the diflference of aspect presented 

 bv the opposite coasts of the island. The east coast is of uniform coutour, and 



Fig. 6. — Geological Map of South-Eastern England. 

 According to Best. Scale 1 : 3,350.000. 



W.oPCr 



1. Alluvia. 2. Upper Tertiary. 3. London Clay, &c. 4. Chalk. ' 5 & 6. Greensand and Quit. 



^^ 



^ 



7. Weald. 



12. Permian. 



9. Lias. 



mm 



13. Carboniferons. 



14. Devonian. 



10 & 11. Triassic, &c. 



16. Silurian. 



60 ailles. 



almost devoid of natural harbours, but their absence is somewhat compensated for 

 by the existence of estuaries ; the approaches to these, however, are often rendered 



* Culminating points of the uplands of Eastern England : — 



Oolitic Limestone Ranges ( ^otswold Hills, Cleeve Hill 

 \ York Moors, Botton Head . 



Cretaceocs Ranges 



i South Downs, Butser Hill . . . 



North Downs, Inkpen Beacon . 



LeithHill . . . 



Chiltem Hills, Wendover Hill . 



1,134 feet. 



1,498 „ 

 883 „ 

 973 „ 

 967 „ 

 905 „ 



