150 UPPER, OR FLINTY CHALK. 



chalk, and flinty chalk, are passed over in succession. The pit is between 

 twenty and thirty feet high, and consists of, 



1. Vegetable mould intermixed with chalk rubble, 1 foot. 



2. Chalk rubble, _.---- S feet. 



3. FHnty chalk, ------ 20 feet. 



The chalk is stratified in horizontal beds from two to four feet thick, 



and these are separated in some instances by layers of flints, and in others 

 by chalk rubble ; flints are also irregularly disposed throughout the mass. 

 This spot is peculiarly interesting, from the circumstance of the strata 

 having been rent asunder since their original deposition. Vertical fissures 

 are every where observable, and these are partially fiUed with broken chalk 

 and flint, cemented together by crystallized carbonate of lime, of a hght 

 amber colour. The sides of the fissures are incrusted with the same sub- 

 stance, which has insinuated itself into the crevices of the surrounding 

 chalk, and also occurs in irregular concretions in the cavities of the flints. 

 The surface of these stalactitical depositions of calcareous spar, is fre- 

 quently covered with delicate undulations, as if the water had been sud- 

 denly congealed, while in a state of agitation. 



Piddinghoe. This pit lies on the road side, near the village of the 

 same name ; it is remarkable for the purity and softness of the chalk, and 

 for the numerous vertical and oblique veins of tabular flint, by which it 

 is traversed. These veins are of a most extraordinary character ; for 

 although the flint retains its original form and situation, yet upon 

 examination, it is found to be cracked and shivered in every direction. 

 The fractured flint falls to pieces upon being removed from the chalk, 

 but in some instances it is held together by sulphuret of iron, forming a 

 conglomerate of silex and pyrites, of a very singular appearance. The 

 phenomenon here remarked, is not however confined to this quarry, 

 but may be observed in several chalk-pits near Lewes and Brighton. 



Sir Henry Englefield was the first who directed the attention of 

 geologists to this subject. In a paper read before the Linnean Society, 

 he notices several beds of shattered flints, which occur in a chalk-pit at 

 Carisbrook, in the Isle of Wight ; and after describing their appearance 

 and situation, proceeds to offer some conjectures upon the probable cause 



