﻿664 



ME. H. BTTEY ON THE DENUDATION OP [Nov. I9IO, 



second patch of gravel (fig. 4, B), lies between Middle and Lower 

 Old Parks, and its relation to the underlying strata resembles the 

 last, though it is slightly higher in level. I have seen no pit in it, 

 and have only been able to study it on the surface of a ploughed 

 field. Many large flints had been collected at the side of the 

 field, and assuming (as is probable) that others had been used to 

 mend the road, the gravel bears a general resemblance to that of 

 the plateau, from which, however, it is now separated by a wide 

 valley. I failed to find a single fragment of chert. Immediately 

 to the west of Lower Old Park is a steep ravine, and beyond that 



Fig. 4. — Gravels in and near the Crondall Pass, with contour-lines 

 and geological structure. 





m,,:,. m 







WA ...--^t : ■ 





.-*"' jO.g.f.f, 



7$ i ^' fp 



\§P Upper Old Parkx^^--' 







Eocene 





\ / /"\400FT. 







i \ ... -Middle ■: ';.••.. ..-■• 



*^ v / 0\<X Parkx'-... y^ .-' 







\ Lower, ••' Jk , • / :"' (f\ '■>. 

 • Old Park: K%- '■ ( <■■': W .;"•■; 







Chalk 











x *&£?%?'' \ 



Upper 

 Greensand 



...*0 o - ; 



.^^^Dippenhal]/' y' ^ ..■■■'' ) '■■■■q° 



Gault 



•••' •P-f.T-.-' 



\--: /' * > '"••••:. \ ^<-?3 





40C? T '-• . 



-€^^^00^^^ ■-'' y^l eS^ 





,»..— •-'* *"S 



«_. /H^^^^^^^ /' J^-^r' 





'"■ ## 



y'^Sy-Jr" S J* 





*•? V) i •;• 



■: / /^^y 



Lower 

 Greensand 



'•..■••' .' / [Scale: i mile = i inc 



h] 



[A & B, chert scarce ; C, D, & E, chert abundant ; F, Plateau Gravel.] 



again, at 426 feet O.D., is another patch of gravel, lying on the 

 Heading Beds (fig. 4, C) ; like the last, it is mapped by the Geo- 

 logical Survey as ' river-gravel,' but it differs entirely in compositiou. 

 I am again dependent on a superficial examination, but even so the 

 abundance of chert is obvious. A little farther south, nearDippen- 

 hall, are two adjoining sheets of gravel (fig. 4, D) lying on Chalk. 

 The best exposure is in a pit rather below the 400 -foot contour, but 

 the Drift extends above that level, and from the large cavities which 

 occur in this pit, and the way in which pinnacles of Chalk project 

 up into the gravel, I conclude that the latter has, at this point, 

 been lowered by the removal of the subjacent Chalk in solution. 

 The percentage of chert in this gravel reaches quite 20 per cent. 



