506 BJIY. A. lEVIXG 02<r A GENERAL SECTION OF TKE 



pebble-bed at Easthampstead church, about a mile to the south, 

 and with that of the pebble-bed of the sections already described 

 at Wellington-College station and at Camberlej- , as well as with that 

 of the pebble-bed at the top of the Middle Bagshots exposed in the 

 cuttings on the new line between Ascot and Bagshot *. 



At the top of the Bracknell cutting iiint-pebbles come in again 

 in great force, the original bed having been, it would appear, 

 reconstructed. I saw them again in great quantity, without 

 observing a single angular fragment of flint among them, in a garden 

 close by Bracknell church ; and at Wick Hill, half a mile further to 

 the north, they are seen lying upon yellow loamy sand, and filling 

 up the hollows of its eroded surface to a depth of three feet, at an 

 altitude of about 285 feet. I could find no evidence to indicate a 

 southward dip in the strata hereabouts, and there is certainly none 

 in the railway-cutting. Moreover, on the slope of Wick Hill a 

 feebler pebble-bed is exposed in the ditch, a few feet only above the 

 London Clay, agreeing in character and position with that exposed 

 in the rail way- cutting (c). There are clearly, therefore, two pebble- 

 beds at Bracknell. That we have good reason for regarding them both 

 as^belonging to the Tipper Division of the Bagshot series, I think I 

 may claim to have shown, though these Bracknell beds are mapped 

 as Lower Bagshot (^. 4). 



General Conclltsions. 



By the evidence given in the preceding sections, I think some 

 new light is thrown upon the physical history of the Bagshot strata 

 of the London Basin. 



1. We have succeeded in tracing pretty clearly the horizon of the 

 Middle Bagshot strata and the base of the Lpper Bagshot across 

 nearly the whole of the country from Aldershot to Wokingham, a 

 distance of about 13 miles. 



2. While in the deep-well sections the order of superposition is 

 clear, and the Lower Bagshot Sands of those sections are charac- 

 terized by the great predominance of green sand, or sand coloured 

 by amorphous matter of vegetable origin, we fail to find such sands 

 along the northern and southern margins of the area. 



3. A passage from London Clay into Lower Bagshot Sands seems 

 pretty clear in the deep-well section at Wellington College, and may 

 exist in the other deep-well sections ; but in the sections described 

 in this paper on the north and south there appears to be no such 

 passage. On the other hand, both on the northern and southern 

 margins higher members of the series than the Lower Bagshot are 

 found lying in close proximity to the London Clay, evidence of 

 unconformity being furnished in several of the sections. 



4. The Bagshot strata, as a whole, do not lie in a synclinal curve, 

 though a true synclinal arrangement prevails in the southern half 

 of the region, which may perhaps be fitly termed the Farnborough 

 Syncline. 



* Vide Monckton, Quart. Journ. Geol. See. loc. eit. 



