34 



W. WHITAKEE ON SOME BOEINGS IN KENT. 



on its continuing northwards with about the same thickness as at 

 Chatham, it would he safer to take only about 130 feet of the boring 

 as in Gault. In this case some 60 feet more should reach the 

 bottom of that formation, and the progress of this boring (which is 

 unfinished) may be of interest in showing us whether the Lower 

 Greensand thins out altogether, as one might expect from its small 

 thickness at Chatham. 



The great thickness of the Thanet Beds here is notable, 121 feet 

 being a good deal more than one would have expected. 



Mr. Lyons has noticed, in a letter to me, that the section of the 

 Tertiary Beds is almost identical with that of the neighbouring 

 Upnor pits *, and has classified the beds accordingly. 



I have had, for some years, an account of a shaft at Chattenden 

 Barracks, which seems to be a diff'erent version of the top part of this 

 well, and may perhaps as well be noticed here. It was taken from 

 a drawing (dated 1876) communicated by the Inspector General of 

 Fortifications, and is as follows : — 



Thickness Depth 

 in feet. in feet. 



[London Clay, /Brown clay 17 17 



102 ft.] [Blue clay 85 102 



[Oldhaven Beds, f Light-coloured silver-sand 5 107 



10 ft.] 1 Shells, sand, and stones [? pebbles] 5 112 



rSand 8 120 



TTTT 1 • 1 X) 1 T Shells, dark earth, and stones 2 122 



[Woolwich Beds.] Sand ;nd shells... 10 132 



1^ Green sand 1 133 



5. Boxley Grange, South of Chatham. 1885. 



Bored and communicated by Mr. R. D. Batchelor, of Chatham, 

 and from information and specimens from Messrs. Dunlop and Co. 



rOldweU 



™ „ ! Hard chalk, with flint, and alter- 



^^^^^ 1 nate layers of soft chalk, with- 

 in out water 



Chalk Marl, and Gault (a fine blue clay, hard and dry) . . . 

 [Dead green sand 



PP , -, J Light-brown clay 



Lbrau .J ^ Darker clay, specimen grey ; also 



[ some crystals of pyrites at 922 ft. 



/'Dead green sand 



Dead green sand with pyrites . . . 

 Dead green sand 



[Lower Greensand, 



or, in part, base of -^ E-ock 



Gault.] 



Dead green sand 



Eiock 



i^Waterworn light-coloured sand. 



Thickness 



Depth 



in feet. 



in feet. 





348 



258 



606 



310 



916 



2 



918 



3 



921 



4 



925 



1 



926 



2 



928 



4 



932 



4 



932| 



¥ 



938^ 



^2 



943 



In this case there is thickness enough for the Chalk, especially 

 as the well does not begin in the topmost beds. A more detailed 

 <^ Geol. Survey Memoirs, vol. iv. pp. 144, 145 (1872), 



