ON THE RESULTS OE SOME DEEP BOEINGS Itf EENT. 



197 



16. Further Notes on the Results of some Deep Borings in Kent. 

 By William Whitaxer, B.A., F.Gr.S., Assoc. Inst. C.E. (Head 

 January 12, 1887.) 



[The fresh information given in this paper is communicated by permission of 

 the Director Greneral of the Geological Survey.] 



Contents. 



Introductory Remarks. 



The Chattenden Boring. 



The Dover Convict-Prison Boring. 



New Boring at Strood. 



Boring at Lydd. 



Introductory Remarks. 



The primary object of my paper read to the Society in 1886 * was 

 to describe the boring at Chatham, which had reached Oxford Clay ; 

 but the paper was extended, to include other borings in Kent which, 

 had passed through, the Chalk, and had not been brought to the 

 notice of geologists. 



Since then further and fuller information has come to hand with 

 regard to two of these borings, and another deep work has been 

 carried through the Chalk and the Gault into the Lower Greensand. 



I have thought it well therefore to send this supplementary paper 

 to the Society, especially as one of the borings, at Dover, has now 

 thrown fresh light on that important and interesting subject, the 

 underground geology of the London Basin. It was originally meant 

 to incorporate these notes with others descriptive of deep borings in 

 Surrey ; but as those borings are not yet finished, and as there is a 

 special interest in the Dover boring, it seems better to let the Surrey 

 borings stand over, and to place the new Kentish information in the 

 hands of the Society at once. 



With regard to the doubt as to the depth of the second Chatham 

 boring, expressed on p. 30, it should be noted that whilst this depth 

 is rightly made 965 feet from the surface, yet it is only 963| from 

 the point from which the measurements were made, the coping- 

 level being 18 inches below the surface. 20 J feet therefore would 

 seem to be the right thickness of Oxford Clay pierced. 



* Quart. Journ. Greol. Soc. vol. xlii. pp. 26-48, pi. iii. Four errors in this 

 paper have been noticed on the wrapper of the May No. of the Society's 

 Journal (1886) ; but they may be repeated here with three others : — 

 P. 29, line 8 from foot, for 450 read 45. 



P. 30, lines 9, 10" from foot, for "below the 450 feet that was dug," read 



"below 450 feet." 

 P. 35, line 5 from foot, for " 180 " read « 280." 

 P. 47, line 15, for " third " read " half." 



P. 47, line 16, for " 2640 " read '.' 1760 ; " and for "double " read " treble." 

 PI. iii. heading, for « S.S.E." read " S.S.W." 



