1823.] the principal Mountain Chaim of Europe, 215 



near the gypsum of Kiel) to the mouth of the Elbe, and thence 

 crosses the German Ocean. 



(B.) England, 



This formation first exhibits those white chfFs which have 

 been supposed to have bestowed on our island one of its ancient 

 appellations at Flamborough Head, in Yorkshire ; and thence 

 stretching to the south-west, traverses England diagonally, till 

 it reaches the British Channel, in Dorsetshire, being broken 

 through, however, in its course by the eestuaries of the Humber 

 and the Wash. The greatest breadth of this formation is in 

 Wiltshire and Hampshire, where it expands into those vast 

 plains which Pennant has appropriately termed the great central 

 Fatria of the English chalk. Hence it detaches two branches 

 to the south-east, viz. the North Downs through Surrey and 

 Kent, to the Dover and Folkestone chfFs, and the South Downs 

 through Sussex, to those of Beachy Head. The interval between 

 the North and South Downs is occupied by the formation of 

 sand, 8cc. inferior to the chalk, constituting what has been called 

 the denudation of the Weald, and extending into the Boulonais 

 on the opposite side of the channel. 



The areas lying between these branches and the main diago- 

 nal chain are occupied by basins of the more recent tertiary 

 deposits, viz. the basin of London, between the main chain and 

 the North Downs, and the basin of the Isle of Wight, between 

 the main chain and the South Downs. The south side of this 

 latter basin is skirted by a curvature of the main chain towards 

 the east, deflecting it so as to cause it to run through the penin- 

 sula of Purbeck and the Isle of Wight. This deflected portion 

 of the chain is remarkable from the circumstance, that its strata 

 are throughout greatly elevated, and generally nearly vertical ; 

 while in other places the angle of the beds of this formation with 

 the horizon rarely exceeds 2° or 3®. 



The height of the chalky Downs in one instance (Inkpen, in 

 Hampshire), exceeds 100 feet, and is often between 800 and 900 

 feet above the level of the sea. 



(C.) France y and tJie Netheriands. 



This formation occupies on the northern coasts of France, an 

 extent exactly corresponding to its line on the southern coast of 

 England. At the mouth of the Seine, its outer edge (which 

 reposes on green sand, having oolite and Has in the neighbour- 

 hood) turns south, and so continues to Blois, where the forma- 

 tions above the chalk overlie and conceal its southern extremity : 

 it reappears at Montargis, and turning again north (for the 

 v/hole chalk district of France forms a sort of Cape protruding 

 to the south of its general line), runs east of Troyes, Rheims, 

 and Valenciennes, having the green sand, oolites, and lias, on 

 its east, till it approaches the latter town, where most of thesei 



