46 



W. WHITAKER ON SOME EORINGS IN KENT. 



Table showing the Distances, in miles, hetiueen the sites of 

 the Borings. 





1 



6 



1 



CD 



e 



1 



4 



% 

 1 



03 



S3 

 



g 



1 



■i 



t 



Chatham 



Cheshunt 



321 

 19 



48 



32 



29i 



37 



32 



37i 



58 

 13 

 14 



22? 

 56 

 6* 



19 



15i 



57 



13 



11 



19* 



41 



22 



48 

 58 

 57 



66 



66* 

 75 



77 

 57 



32 

 13 

 13 

 66 



"3 

 10 

 49 



18 



291 



14 



11 



66'^ 

 3 



"9 

 46 

 20 



37 

 22? 

 19* 

 75 

 10 

 9 



48 



27 



32 

 56 

 41 



77 

 49 

 46 

 48 



63 



37i 

 61 



22 

 57 

 18 

 20 

 27 

 63 



Crossness 



Harwich 



Kentish Town 



Meux's 



Richmond 



Sub-Wealden 



Ware 





The section is made from parts of sheets 78 and 84 of the 

 " Horizontal Sections" of the Geological Survey, the former of which 

 runs across the "Weald near Goudhurst and Marden, and the Lower 

 Greensand tract near Maidstone, to the Chalk above Boxlev, the 

 latter then continuing the course down the dip-slope of the Chalk, 

 over the Medway, through the Tertiary tract of the Hundred of Hoo, 

 and over the Thames, into Essex. 



The inferred positions of the bases of the Chalk and of the Gault 

 in those sections have been corrected, and the geology has been 

 carried somewhat deeper in the northern part (sheet 84) and to a 

 much greater depth in the southern (sheet 78), in which latter, 

 indeed, it had not been taken below the line of the sea-level, except 

 just by the junction with the other sheet. 



The Subwealden boring is on an exposure of Purbeck Beds 

 between 5 and 6 miles eastward of the one crossed at the southern 

 end of the section. The Boxley-Grange well is only about half a 

 mile east of the section, near the Chalk escarpment. The Chatham 

 wells are in a part of the Medway marshes about two miles westward 

 of where the section crosses them. The Chattenden well is on the 

 Tertiary hill north of the Medway, about the same distance from 

 the section and on the same side of it. All these therefore have 

 been available in estimating the position of the beds underground. 



Whilst the section is an attempt to show, in a general way, what 

 happens underground in the tract it crosses, of course it cannot 

 pretend to exactness, either as to the places where the various 

 thinnings-out of formations take place, or as to the manner in which 

 they occur. Such formations as the Corallian and the Purbeck, 

 being of comparatively local character, have been ended off fairly 

 soon, whilst the thick deposit of Kimeridge Clay may be presumed 

 to reach further. Again, though the various formations have been 

 drawn as thinning out in a gradual way, it is very likely that there 



