GREY CHALK MARL. 99 



XI. 

 § II. 6. GREY CHALK MARL. 



This deposit constitutes the foundation of the chalk hills, its outcrop 

 forming a fillet, or zone, round their base, and connecting the detached 

 parts of the range with each other. 



The texture of the marl is commonly soft and friable, but indurated 

 blocks occur, which possess the hardness of limestone. It is of a hght 

 grey colour, inclining to brown, and frequently possesses a ferruginous 

 tinge derived from oxide of iron. It principally consists of carbonate of 

 lime and alumine, with an intermixture of silica, a very small proportion 

 of iron, and perhaps of oxide of manganese. 



Where denuded, the surface of this deposit composes a fertile tract of 

 arable land, including some of the best farms in the county. 



In the range of low cliffs near Eastbourne, the grey marl is seen rising 

 from beneath the chalk, and reposing on the grey sand, with which it is 

 intermingled at the line of junction. Its separation from the super- 

 incumbent bed of chalk without flints, is well defined, and may be traced 

 with but little difficulty. From this spot it extends with scarcely any in- 

 terruption, to Shoreham river, its outcrop being interposed between the 

 foot of the Downs, and the basseting edge of the blue marl. 



In western Sussex it occupies the same relative position, the lower 

 chalk passing insensibly into the grey marl, and the latter into the malm 

 rock. 



In its course through this tract of country, it forms a few hillocks or 

 mounds of low elevation, which are remarkable only for the abundance 



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