W. WHITAXER OX SOiTE BORENGS IX KEXT. 37 



perhaps not known to many of our ILembers, and at a site well 

 fitted for further experiment. 



St. ]\Iargaret's, near Dover. Trial-boring for the Channel Tunnel 

 Company [on the shore]. Prestwich, Proc. Inst. Civ. Eng. [1874.] 



Thickness Depth 



in feet. in feet. 



Shingle 9 9 



/^White chalk 209 218 



_.^ ^- ., I Yellow chalk 4 222 



^S ^A^i^^l White chalk 4 226 



Chalk, 240feet. ^ j,.^^^^^,^ (saltwater) 3 229 



I, White chalk 20 249 



,^ Grey chalk 30 279 



White chalk 10 289 



Blue marl 11 300 



Pipeclay 42 342 



Light-blue clay 158 500 



Light stone 1| 501| 



Light clay 1^ 503^ 



I Stone 1| 504J 



Lower or Grey-{ Clay* 2^ 507 



Chalk, 299 feet. Stone ij 508^ 



Clay* 3 51U 



Stone 1| 513| 



Clav* 10 ,523^ 



Stone li 524^ 



Clay* 10 534f 



I Stone ^ 535 



I Clay* 10 545 



(Greensand [= base of the Chalk Marl] ... 3 548 



GaultClay 19 567 



C. Geological Eestjlts op the Boeixgs. 



Having the details of the two Chatham, borings before us, together 

 with those of the neighbouring Cement Works bore, we may now 

 pass in review the various formations pierced, and see what infor- 

 mation has been given by the work. Until the Chattenden boring 

 has had further examination, I fear that it cannot help us much, 

 except in so far that it gives the full thickness of the beds between 

 the London Clay and the Chalk, a matter with which we have now 

 no particular concern. 



In the first place, with regard to the beds above the Chalk at the 

 Dockyard, we learn but little ; this, however, is of no moment, as 

 the excavations for the neighbouring basins gave very fine sections 

 of the alluvial beds ; and it may be of interest to note that one of 

 these sections yielded what may fairly be described as the largest 

 fossil in the world — to wit, a Dutch Man of War, one of the fleet 

 that sailed up the Medway in the time of Charles the Second, 

 was sunk, and then buried by the river-deposits. The occurrence, 

 however, of a few feet of loam between the gravel and the Chalk is 

 of some importance ; for if, as seems most probable, this represents 



* "Clay" (in the Chalk) is probably ussd in the sense of marl, or marly 

 chalk. One is hardly disposed to accept the above classification of Upper and 

 Lower Chalk, but inclined rather to end the former higher up. 



