between Christchurch Head, Hampshire, and Studland Bai/, Dorsetshire. 285 



water or saltwater character of the shells inconsistent with the supposition that 

 the various beds belong to a contemporaneous formation, which their relative 

 position, their organic remains and mineralogical characters, indicate. If this 

 series of strata was originally deposited in friths, estuaries, or in shallow 

 seas, the phaenomena are such as might be expected. 



Diluvium. 



The diluvium which covers the cliffs between Christchurch Head and the 

 mouth of Pool Harbour, consists chiefly, as I have observed, of flint-gravel ; 

 but in some parts layers of sand are interstratified with considerable regula- 

 rity. The flints have been derived from the chalk ; they are broken and 

 partly rounded, but a great portion retain much of their original form and of 

 the white coating peculiar to chalk flints. They do not appear to have been 

 ever subject to the continued action of the waves ; and there is a striking- dif- 

 ference between the appearance of the flints in the diluvium, and the shingle 

 composed of round pebbles on the beach below, though the latter is formed 

 of the same materials. This remarkable bed of flint-gravel, sometimes 30 feet 

 or more in thickness, is strewed uniformly over the several formations which 

 occupy the cliffs between the eastern extremity of Hordwell Cliff and the mouth 

 of Pool Harbour. There is no observable difference between the charac- 

 ters of this diluvium, whether it covers the lower freshwater formation, the 

 London clay, or plastic clay. The only spot in which an exception occurs, is at 

 the western end of High Cliff, where the sand of the plastic clay first rises 

 below the London clay. At this point the section is as follows, beginning at 

 the top : — 



Vegetable mould 2 feet 



Gravel ' 2 



Green loam, identical with some of the London clay of Highcliff, in which 



green earth is as abundant as in some of the Shanklin beds 2 



Flint gravel ■ 4 



Sand 3 



Gravel 4 



Sand of plastic clay thickness unseen 



The difference in the nature of the diluvium in this place is doubtless con- 

 nected with the formation of the valley of the Stour and Avon ; for it is the 

 eastern slope of this valley which is here intersected by the coast section. 

 The chines or small valleys between Christchurch Head and the mouth of 

 Pool Harbour are hollowed out of strata composed of soft materials, as clay- 



