150 MR. W. H. HUDLESTON ON A SECTION THROTJGH 



gravel, which is connected, more or less, with the present valley 

 system, and it is, indeed, sometimes hard to distinguish the two." 

 Prof. Rupert Jones *, referring more especially to the neighbourhood 

 of Camberley, estimates the depth of the Plateau-gravel with loam 

 at 12 feet (p. 433), and he also remarks (p. 438) that " it is not the 

 Tertiary sands that form the actual surface of the Bagshot district, 

 but certain gravels which have been referred to as coating the 

 plateau and hill-tops The gravel consists chiefly of sub- 

 angular flints from the Chalk with Tertiary pebbles (usually dark 

 in colour); there is also a large percentage of chert from the 

 Neocomian sands of South Surrey, a free sprinkling of quartz in 

 small pebbles (rarely so large as a thrush's egg), and occasional 

 large blocks of concretional sandstone from the Bagshot Sand." 

 Purther on, the same author describes the character, and discusses 

 the origin of the Plateau-gravel, alluding especially to the formation 

 of " iron-pans " therein at various levels, but more especially at the 

 bottom, and shows how such pans have acted in the preservation of 

 the underlying sands. 



The Bagshot Beds of the Weybridge district were noticed in Prof. 

 Prestwich's classical paper written in 1847 1- The author observes 

 (p. 381) that " at St. George's Hill near Weybridge the [Lower 

 Bagshot] sands may be traced from the London Clay at the base of 

 the hill to the outcrop of the green sands [Middle Bagshots] about 

 halfway up it, a thickness of about 130 feet." He also says, " This 

 division [viz. the Lower Bagshot Sands] reposes conformably on the 

 London Clay,^^ adding in a note, " This was well exhibited in the 

 railway-cutting through St. George's Hill. At the end, near the 

 Walton station, I traced the London Clay for a distance of several 

 hundred feet passing conformably below the Loiver Bagshot Sands.'' 

 This is quoted by Mr. Whitaker J in 1872 in describing the main 

 tract of the Lower Bagshot Beds. Very interesting lithological 

 details of these beds are given by Prof. Prestwich, who, amongst 

 other things, has noted an instance § in Goldsworthy Hill of the 

 lateral passage of these light-coloured siliceous sands into a dark- 

 grey laminated clay. This occurs at the top of the series and 

 immediately below the Middle Bagshots. 



Details oe the Section. Block A. (See fig. 3.) 



The line at Walton station is on the level of the country, and as 

 we proceed westward the rise for the first 60 yards is so slight that 

 no certain exposure is yielded; such indications as exist are of a 

 sandy character. The first bed which becomes distinct is the " Top 

 Sand," here about 2 feet thick. At the point marked m (fig. 3) we 

 find indications of the " Mixed Gravel " series (^' of the general 

 section), and water is noted in the gutter for the first time. The 



* "Excursion to Oamberley," Proc. Geol. Soc. vol. vi. p. 329, and "Geology 

 and Physical Features of the Bagshot District," ib. p. 429. 

 t Quart. Journ. Geol. Soc. vol. iii. p. 387 et seq. 

 I ' Geology of the London Basin,' p. 315. 

 § Loc. cit. p. 382. 



