162 ME. W. H. HTJDLESTON ON A SECTION THEOTJGH 



Some of the clay is intensely greasy. There is one phase which 

 occurs so frequently that it may be deemed characteristic. It is 

 where the dark unctuous clay is pervaded in a very singular manner 

 by very fine grey sand, which can neither be said to occur in seams 

 nor in layers. This peculiarity is recognized by well-sinkers, and 

 serves to distinguish it from the London Clay. Towards the south- 

 east of St. George's Hill, about a couple of miles from our section, 

 there is a well which is said to go through a great many feet of " blue 

 sandy stuff," which is not London Clay. Part, at least, of such a 

 well-section may be in the "Blue Bagshots ;" but if so, they must 

 have thickened enormously. To a certain extent one is prepared 

 for this thickening by an inspection of the vertical section of the 

 Bagshot strata disclosed in the trial-boring for the deep well at 

 Wellington College supplied by Mr. Irving*, who gives no less than 

 35 feet of " blackened marl and clay, laminated in its upper portion." 

 That author remarks, with reference to the Wellington- College bore- 

 hole, that the uppermost 25 feet of the bed referred to are strongly 

 laminated ; the remaining 10 feet pierced have more the character 

 of London Clay than anything else. "Here then," he says, "we 

 seem to find a passage of the London Clay into the Bagshot SandsT 

 I would only remark that nothing whatever of the nature of marl 

 has occurred to me in connexion with any of the Bagshot beds of 

 our district ; indeed the amount of calcareous matter in all the beds 

 is exceedingly small. 



On the whole, No. 2 of the Walton-Common section is tolerably 

 impervious ; and, whether it is in contact with the Plateau-gravel, 

 or with higher beds of the Bagshot series, there is generally a strong 

 ferruginous pan at the top of it. Undoubtedly this is the bed which 

 has to answer for some of the peculiar water which the Lower 

 Bagshots are known to afford. The well-sinkers say that " people 

 don't like 'blue-clay' water; it has got a skin like grease." This 

 may of course, in some cases, refer to water at the top of the London 

 Clay ; but I am inclined to think that in the Oatlands district it 

 mostly refers to the water of the " Blue Bagshots." A well-sinker, 

 of the name of Gray, whom I saw lately, tells me that he sank a 

 well on the slope between Oatlands Park and Lower Weybridge, 

 and that at about 30 feet below the mouth of the well he went 

 through a bed of coal in the "blue stuff'." This bed of coal was 

 1^ inch thick, and burnt readily : he calculates the position of this 

 bed to be about 10 feet below the level of the river Wey. Hence 

 there is a probability of organic contamination in many places where 

 the "blue stuff'" is developed. 



No. 2 corresponds most probably with the Ramsdell Clay men- 

 tioned by Mr. Whitakerf, who observes, "that on a close exami- 

 nation it was also remarked that the Ramsdell Clay bore a kind of 

 resemblance to the pipe-clays of common occurrence in the Bagshot 

 Beds, and for this reason probably it is adapted for making tiles (a 

 purpose for which London Clay is seldom suitable), being an impure 



^ Proc. Geol. Assoc, vol. viii. p. 144, and Q. J. G. S. vol. xH. p. 494. 

 t ' Geology of the London Basin,' p. 312. 



