280 Dr. PiTTON on the Strata below the Chalk. 



Sections at Brill. 



A. — In a pit at this place, open in 1827, the following beds were visible above the Portland 

 strata : — the whole (perhaps from subsidence) inclining towards the north-west. 



{_Lower Green-sand.^ Ft. In- 



1 . Grey and yellow sand about 6 



2. Alternate layers of ferruginous sand, and of clay used for making tiles. Near the 1 , - 



bottom the seams are oblique to the stratification J ^ 



3. Black and grey, alternating with whitish and ferruginous, sand, and including flakes! 



6 



of yellow ochre J 



A thin course of clay (Fuller's earth), of various colours, green, wax-yellow, and red- " 

 dish, with a subconchoidal fracture, and a wax -like, almost resinous lustre exter- 

 nally, like jasper. The polish of the pieces is evidently the result of movement under 

 strong pressure. — See the description of a similar clay at Tilburstow m Surrey, 

 supra, p. 139 about J 



Sand, increasing in firmness as it goes down 4 



[No indication here of the Purbeck strata^] 



Portland stone, — containing Trigonias and other characteristic fossils, among which "1 

 Pecten orbicularis is one of the most abundant J 



B. — At a clay pit about 20 feet below the road on the south-west of Brill, the beds, declining 

 to the west and south, were thus : — 

 [_Lower Green-sand.^ 



1. Sand ; white at top, yellow, and ferruginous below 6 to 7 



2. Gravel, with concretions of "Carstone"; coarse quartz sand, cemented by oxide of) 



iron J 



3. Yellow ochre, of very good quality, much used in commerce 1 8 to 1 10 



4. Clay; containing thin bands of ochre, a quarter of an inch and less in thickness.. .about 1 



5. Clay ; light bluish grey, uniform : here visible to a depth of about 5 



No shells of any kind are known to occur in this bed ; but about six feet down an 

 entire tree was found, converted into lignite much mixed with pyrites. The trunk, 

 about a foot in diameter, and full 40 feet long, lay almost horizontally, nearly east 

 and west; and branches extended to about 10 feet beyond it on both sides, be- 

 ginning about 25 feet from the extremity. It was preserved and shown in an adjoining 

 house as an object of curiosity ; and though in a state of ruin, when I saw it, from the 

 decomposition of the pyrites, was one of the finest fossil specimens I had ever seen. 

 Beneath the tree, it had been ascertained by boring, that clay, but of darker colour, 

 extended to about 12 feet in depth. 



C. — In another pit, on the outside of the inclosure where the tree was found, the strata 

 were: — 



Grey sand about 5 



(5.) Clay, said to be the same with (5.) of the list above ; but darker and of more slaty 

 structure. It is very like 4. of the List A. above, and breaks into pieces with po- 

 lished surfaces : the lower part for about two feet alternates and is mixed with yellow 



ochre _ 



The place of this clay in the series seems to correspond best to that of the Fuller's 

 earth at the bottom of the Lower green-sand ; and it falls to pieces slowly, in water, 

 like that substance : but I could not determine its relations to my own satisfaction.] 



6. Yellow ochre, of a duller hue than (3.) above ; some Fuller's earth at the lower part. .about 



U 6 



