LOWER CHALK. l39 



XII. 



§ II. 7. LOWER CHALK. 



The absence of siliceous nodules, and the superior hardness of the 

 chalk, distinguishes this deposit from that which lies above it. 



Its colour is of a light grey, enclosing masses of pure white. It forms 

 the low elevations at the foot of the Downs, and as the situations it occupies 

 are generally easy of access, a considerable number of quarries have been 

 opened in different parts of its course. It is regularly stratified, the hues 

 of separation being composed of a softer chalk, that in some places con- 

 tains so great a proportion of argilla, as to assume the appearance of marl. 

 The latter also occurs in transverse and vertical veins, in which the remains 

 of fishes are more frequent than in the more solid strata. 



The general inclination of the beds is towards the south-east, at an 

 angle of from 5° to 15°. Their total thickness has not been determined, 

 but is probably not less than 200 feet. A well sunk on the side of the 

 hill, near Glyndbourne, passed through 120 feet of the lower chalk only. 

 The lowermost beds were of a deeper grey than the upper, but presented 

 no other material variation. The cliffs that extend from near Beachy 



in the vicinity of Dover, described by Mr. Phillips {Geological Transactions, Vol. v. p. 18.), 

 are separated by that gentleman into the following, viz. 



1 . Chalk with numerous flints, 350 feet thick ; which is subdivided into 



1. A bed with few organic remains. 



2. Chalk with interspersed flints, consisting chiefly of organic remains, in which nu- 

 merous flints of peculiar forms are interspersed, and a few beds of flint. 



2. Chalk with a few flints ; this stratum is about 1 30 feet thick. 



3. Chalk without flints, 140 feet thick, consisting of 



1. A stratum containing very numerous and thin beds of organic i-emains, 90 feet 

 thick. 



2. A bed 50 feet thick, with few organic remains. 



4. Grey chalk, estimated at 200 feet in thickness. 



T 2 



