448 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 24, 



Tiinbridge *. Here, on the north of the Medway there is a plateau, 

 several square miles in extent, covered by a deposit of gravel and 

 brick-earth. About Hadlow the brick-earth predominates, and forms 

 a rich soil of much value for the cultivation of hops. At Hadlow 

 the level of this plateau is 40 or 50 feet above the river, and north 

 of Hadlow it is nearly as much as 80 feet. A little east of Hadlow the 

 ground slopes down gradually to the Medway, and the higher river- 

 deposits join on to the lower without any distinct line of separation. 

 In places the gravel and brick-earth have been cut through by small 

 streams, which expose the Weald Clay beneath. 



A good section of the gravel is seen at Goose Green, near Had- 

 low, where a pit shows 15 feet of gravel, which consists of pebbles 

 of Wealden sandstone, angular and subangular pieces of flint and 

 chert, besides Tertiary pebbles. False-bedded coarse sand is found 

 interstratified with the gravel. 



Brick-earth is dug at a place marked Pottery on the Ordnance 

 Map ; on the southern side of the pit stratified brick-earth 13 feet 

 thick is seen, with scarcely a single pebble ; a little further north 

 false-bedded sand and gravel ai-e interstratified with the brick- 

 earth, and in one place there is an interesting case of disturbance, 

 to which reference will be made later. Fcav other sections of brick- 

 earth are to be had, as it forms such a good soil that it is more pro- 

 fitable to cultivate hops than to dig the earth for bricks. 



North of Tunbridge several patches of gravel occur of consider- 

 able interest. 



The outher north-east of Starve Crow Farm is, at its highest part, 

 180 feet above the river at Tunbridge. This gravel has been much 

 dug for roads : it appears to be 14 or 15 feet thick ; the springs on 

 North Fright Farm are at that depth. Other patches of gravel are 

 found near here at about the same level. 



Junction of the Plaxtole and Medway Gravels. — Just east of the 

 village of Plaxtole the Greensand range is broken by a valley 

 running northwards up towards the Chalk escarpment, which, how- 

 ever, shows no corresponding feature. Along this valley a stream 

 runs southward to join the Medway. 



About half a mile south-east of Plaxtole is a patch of gravel 

 about 60 feet above the stream, in which we can clearly trace the 

 junction of the old Medway with the old stream that flowed through 

 the Greensand escarpment. Along the south of this outlier Weal- 

 den and Tertiary pebbles, with pieces of flint and chert, occur. The 

 gravel is well seen resting on clay on the road going south from 

 Plaxtole. A brickyard just east of this gave, in August 1864, the 

 folloAving section : — fj. -^^g 



Gravel not well bedded 2 6 



Good gravel interbedded with coarse sand and a 



little clay 4 



Blue clay (Wealden) 



* There are beds of gravel higher up the Medway than Tunbridge, but not of 

 sufBcient importance to claim notice here. They will be described in the 

 Meraoir on Sheet 6 of the Geological Survey-map. 



