158 PKOF. J. PEESTWlCn ON A SOUTHERN DEIFT IN THE THAMES 



Though Lower Greensand debris is extremely scarce in this 

 gravel, there is, lower down (500 feet above O.D.) on the south side, 

 and resting on the Chalk-plateau, at a spot above the railway-tunnel 

 opposite Colegate Earm, a small patch of gravel composed in large 

 part of fragments of chert and ragstone. Another small patch caps 

 the hill with the clump of trees (366 feet) just north of LuUingstone 

 Park. 



More recently, I have discovered a bank of this gravel, very coarse 

 and with much chert and ragstone, some of large size, on the slopes 

 of the hill on the left bank of the Darent, between Eynsford and 

 Farningham. There it does not cap the hill, but extends on its 

 slope from 250 feet nearly to the summit at 350 feet. It is not 

 worked, but, being bare, is easily examined. 



Thence westward to the borders of Surrey I know of no well- 

 marked body of this gravel (unless a sprinkling of flint-gravel on 

 the top of Eed Hill near Chislehurst should be grouped with it), 

 although here and there on the Chalk-plateau there is, as on the 

 downs east of the Darent, an occasional thin sprinkling of chert- 

 fragments and much-worn brown-stained flints. 



Surrey. — Here it is on the Tertiary hills, and not on the Chalk- 

 downs, that we find the best exhibition of this Southern Drift. A 

 thin bed of it resting on London Clay caps West-Ho Hill. Norwood 

 (see Plate YII. fig. 3). 



The following is a detailed section taken some years since : — 



Fig. 1. — Section of Gravel-pit on West-Ho Hill*, 



ft. in. 



a. Surface-soil 2 



6. Loamy gravel 1 



c. Fine ocln-eoiis gravel witb veins of grey sandy clay 1 



d. Grey sandy clay 6 



c. Yellow gravelly sands 2 



/. Grey sandy clay fi 



//. Ocbreous sand 1 3 



h. Grey sand 3 



i. Coarse ochreous gravel 2 0+ 



* This pit is now probably built over. 



