202 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 5, 



Section of Railway Cutting at Brentford. 



1. Vegetable mould ; 1 foot. 



2. Brickearth, a fine bro'RTiish loam ; 4 feet. 



3. Fine sand, mostly stratified and obliquely la- 



minated, with occasional wavy and irregular 

 veins of small gravel ; 6 feet. 



4. Sand, with light- coloured clay and irregular 



gravel, containing bones ; 6 to 8 inches. 



5. Ferruginous gravel and sand, with patches of 



clay ; 1 foot. 



6. Clayey sand and sandy gravel, with occasional 



large flintstones, partly ferruginous at the 

 upper part, containing bones and shells; 1 

 to 2 feet. 



7. Ferruginous sand and gravel ; about 6 inches. 



8. Light clayey sand and ferruginous gravel, with 



boulders of quartz, granite, rock with am- 

 monites, &c., also bones, &c. of ox, deer, 

 &c. ; 6 to 7 feet. 



London clay. 



third of a mile, and presented great variations in the order and rela- 

 tive thickness of the sands and gravel, which pass into one another 

 in a very irregular manner. 



No remains were, I believe, found in the brick earth and sand 

 (2 and 3) ; the sand (3) throughout its whole extent was stratified 

 and obliquely laminated, some of the layers being more ferruginous 

 than the others, and occasionally interstratified with veins of small 

 gravel ; the ferruginous gravel (5) is of less regular thickness, the 

 upper surface being sometimes eroded and the hollows subsequently 

 filled with a coarse greyish sand and light clay (4), containing bones ; 

 the clayey sand (6), also containing bones, is the chief depositary of 

 the shells, which were generally in a perfect state of preservation, the 

 Anodons retaining their usual brown epidermal covering. 



The chief mass of the ferruginous gravel (7) consisted of rounded 

 and angular chalk-flints of various sizes ; but occasionally intermixed 

 with them were a few pebbles and small boulders of other rocks, as 

 London clay septaria with Teredince, indurated greensand, sand rock 

 with ammonites, fragments of pyritical ammonites (Oxford clay?), 

 coarse reddish sandstone, white quartz, granite, &c. 



The bones, although occurring in all the layers below No. 3, were 

 most abundant in the lowest stratum ; on one side of the railway, a 

 vein of sand, containing shells, was observed, intercalated with this 

 gravel bed. Below the gravel bed is the London clay upon which 

 the whole deposit rests, but the depth of the clay was variable and 

 not accurately determined. 



