110 



THE GEOLOGIST. 



To those readers who may not have 

 studied the geology of Kent, I may state 

 that our principal knowledge of the 

 Lower Tertiary formations there are 

 derived from those excellent papers on 

 the Thanet sands, and the Woolwich 

 series by Mr. Prestwich, in the Geolo- 

 gical Society's Journal ; and it will be 

 remembered that these sands are the 

 British representatives of the Lowest 

 Tertiary or Lower Eocene deposits. 

 These series are abundantly exhibited 

 overlying the chalk in the railway-cut- 

 tings' between Woolwich and Canter- 

 bury. The lowest more particularly in 

 the cuttings between Canterbury and 

 Beakesbourne, which Iwillnow describe. 



The London, Chatham, and Dover 

 Railway, after crossing the valley of the 

 Stour, passes to the south-east of Can- 

 terbury, and the first cuttings are 

 through chalk. It crosses the Dover 

 road at about a quarter of a mile south- 

 east of che town ; the depth of the cut- 

 ting in the chalk being about twenty 

 feet — that is to say, there is a depth of 

 about fifteen feet of chalk, and over it 

 a depth of five feet of brick-earth (post- 

 Pliocene). Between the chalk and the 

 brick-earth is a stratum of irregular 

 flints, about six inches in depth, as 

 shown in the accompanying diagram. 



In No. 1, a represents the chalk ; 

 b the flint stratum; and c the drift. 

 In No. 2 cutting, c represents the drift, 

 and d a stratum of sand of ochreous 

 colour, having a thin stratum of iron- 

 stone; supposed by me to represent the 

 Woolwich sands. In No 3 cutting, c 

 represents the drift; d the Woolwich 

 sands ; e the glauconite; / the grey 

 plastic marl. These two last represent 

 the Thanet sands of Prestwich; but 

 seem to differ in their lithological cha- 

 racter from those described by him. 

 There is nothing particularly worthy of 

 note in c and d\ but stratum e is 

 composed of an indurate greenish 

 sandstone, in its upper portions ap- 

 proaching in colour to the , ochreous 

 sand at d, having chertstone inter- 

 spersed. Tins sandstone is very hard 

 in places; but not in large blocks. 

 II appears split into perpendicular and 

 transverse sections, and abounds in 



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