Feet. 



Id. 



4 









to 



6 







about 



8 







124 Dr. FiTTON on the Strata below the Chalk. 



rushes ; probably thirty-five to forty feet in thickness, down to the sea : — of 

 part of which the section is as follows : — 



(6.) r 



1. Yellow sand ; face nearly vertical, from a recent fall s 



2. Dark smoke-grey, crumbling, sandy clay, or cohesive sand, greenish at the 



bottom 



3. A band of firmer green-sand, splitting horizontally into very thin layers, from the ' 



interposition of lighter-coloured sand, which seems to occupy the place of thin 

 cylindrical stems or twigs. 



In this bed the hammer leaves a mark of a vivid green colour, but the general 

 hue is dark greenish grey. It consists of very minute particles of quartz, in- )> 9 

 timately mixed with a large proportion of the silicate of iron, soft, and of a 

 full green colour ; not effervescent, except in minute spots. The gradations from 

 this compound through all shades of colour and consistence, to brown, and even 

 yellow, sand, are imperceptible _ 



4. Dark greenish grey sand, apparently continuous with, and passing into, the tena- "1 -Uoy* 



cious matter of the lower beach f 6 



about 



Total, about 20 feet. 



The bottom of this group is concealed by the loose gravel of the beach. 



(28.) A striking- characteristic of the middle group (6.) is the great diversity 

 of hue and consistency which it assumes under different circumstances. The 

 colour when dry is frequently a rusty yellow ; — but in other states, con- 

 nected perhaps with the different degrees of oxidation of the iron, or with 

 the decomposition of the pyrites, which it frequently contains, it is of a dark 

 greenish hue, and passes rapidly from the consistency of loose dry sand to a 

 tough cohesive mass. In these respects it resembles the middle portion of 

 the cliffs in the Isle of Wight. 



Near the bottom, immediately above the stone of the group (c), this middle 

 stratum consists of a dull greenish, sandy, and mud-like substance, appa- 

 rently a mixture of clay with the green particles, which becomes plastic, 

 and almost black in water. In these dark sands, near Seabrook, are decom- 

 posed fragments of petrified coniferous wood*. 



(29.) The third group (c.) of the Lower green-sand first rises on the shore 



* The Rev. G. E. Smith informs me, from Sir JohnTylden, that the high tides in the spring of 

 1833 having laid bare the strata, the latter had an opportunity of observing the lowest bed, of 

 what he not unaptly calls the ' Blue Division,' on the shore between Shorn Cliff and the village 

 of Sandgate. " It is," he says; " very marly, and includes a great quantity of wood and pyrites, 

 " and in places resembles the gault of Eastware Bay." The " very marly" beds may probably be 

 the equivalent of the Fuller's earth of Surrey, &c., which has not, that I know of, been distinctly 

 seen in this part of Kent. 



