272 A Geological Sketch of the Valley of the Kennet. 



which, long after their formation spread over the country the 

 present superficial coating of gravel. But a considerable area of 

 them still remains. On the south side of the Kennet they crop 

 out in many places, and a good section of them may now be seen, 

 in junction with the Woolwich and Reading beds, at Kintbury 

 brickyard, north of Pebble Hill. 



-c Basement-bed 

 of 

 London Clay 



md 



:3g^ Bottom of 

 -^ Basement-bed 



Reading Beds 



a. Tough ferrnginous-brown clay. 

 At about 16 inches from the 

 bottom there are occasional flat- 

 tened concretionary nodules of 

 clay-iron-stone, about 3 inches 

 thick, under a layer of scattered 

 flint-pebbles (h), which are for 

 the most part small and white. 



c. Ferruginous-brown sandy clay or 



clayey sand, about 4 feet. 



d. Black clay ; very hard and homo- 



geneous and splitting up wheu 

 dry very unevenly with a sort of 

 conchoidal fracture, about 3 feet, 



e. A line of flint pebbles. At the 



out crop this bed forms a con- 

 tinuous band of clay-ironstone 4 

 or 5 inches thick, with small 

 imbedded flints. 

 /. Greenish loamy clay passing down- 

 wards into more decided solid 

 clay at the depth of about 3 feet. 



Fig. 1.— Junction of London Clay and Woolwich and Reading Beds at Kintbury Brickyard, 

 North of Pebble Hill. 



In places where these strata occur in their normal condition, as 

 e.g. in. the vicinity of London, they are from 380 to 480 feet ir 

 thickness, but in. this district they have been much denuded 

 Westward from Reading they gradually thin off, and terminate in 

 some shallow outliers near Great Bedwin. Fossils in great variety 

 and abundance are generally found in the formation, although here 

 they are comparatively rare. The places in which they occur most 

 plentifully are the clay-pits at Kintbury, Shaw, and on Kingsclere 

 Common. Besides shells, all of which differ from living species, 

 those clay-pita have yielded fossil- wood, bones of turtles, sharks' 



