44 Mr. William Whitaker on some 



occur in such force not so very many miles to the south, where 

 they crop out to the surface. 



Thus the Lower Greensand, some 300 feet or more thick in 

 its range through Surrey, has almost disappeared, heing repre- 

 sented, and that somewhat doubtfully, by only ten feet of lime- 

 stone (with a little clay). The still thicker mass of the next 

 underlying formation, the Weald Clay, has wholly disappeared, 

 as also is the case with the next succeeding Hastings Beds, 

 which are some hundreds of feet thick at their outcrop, in 

 Sussex. We have therefore a thinning of 1200 to 1500 feet, or 

 more ; and in this we do not reckon the great thickness of Upper 

 and of Middle Jurassic beds, proved in the Subwealden boring, 

 near Battle, the latter division havmg also been found lately at 

 Chatham, where a boring at the Dockyard Extension has proved 

 the presence of Oxford Clay next beneath Lower Greensand.^ 



The Caterham well has pierced the greatest thickness of 

 Gault yet found in England, far in excess indeed of any 

 estimate that could have been made a dozen years ago. The 

 persistence of this formation in all the deep borings in the 

 London Basin is noteworthy. To the base of the Gault we find 

 constancy, and a proper regard for the geological sequence of 

 formations; but after passing that limit we encounter irregu- 

 larity of a most unpardonable kind (to those who expect an 

 orderly succession), so that no man can tell what may be found 

 at any spot several miles from the outcrop of the Gault. 



The figures stand for feet, unless otherwise stated. [Remarks 

 in square brackets have been added by me to the accounts of the 

 sections.] 



Anerley.— A'o/-(/( Surreij District School, Anerley Road. 

 Communicated by the Board of Management. 



FT. IN. 



[London Clay, f [Clay] 220 



228 ft.] (Bhieclay 8 



/Clay and shells 5 6 



Plastic clay 7 6 



Shells 1 6 



Shells and clay 2 4 



Mottled clay 7 



Sand 2 



iPebbles 2 6 



^ Green sand 17 6 



[Thanet Sand, 1 Grey sand 19 



48ift.] I Dead sand 9 



(Flints 3 



Chalk 109 6 



[Woolwich 



and 

 Reading Beds, 



26i ft.] 



412 6 



8 See 'Guide to the Geology of London and the Neighbourhood,' Ed. 4. 

 pp. 19—21. (1884). 



