1855.] 



PRESTWICH — BORING AT KENTISH TOWN. 



13 



Section of the Boring at Kentish Toion. 



London Clay J 

 (236 ft.). I 



CO 

 < 



< 



M 

 PS 



Eh 



QO 



M 



Woolwich and 



Reading Series 



(61 ft. 6 in.). 



Thanet Sands 

 (27 ft.). 



Middle Chalk 



with flints •{ 

 (244 ft. 6 in.). 



Lower Chalk 



without flints « 



(294 ft.). 



Depth, 



ft. in. ft. in. 



1. Yellowclay 30 6 



2. Blue clay, "with Septaria 205 6 



3. Mottled (red, yellow, and blue) clay 37 6 



4. White sand, with flint-pebbles 6 



5. Black sands ; j»flS5m^ m/o 2 



6. Mottled green and red clay 1 



7. Clayey sands 3 



8. Dark-grey sands with seams of clay 9 6 



9. Quick-sands, ash-coloured 6 6 



10. FUnt-pebbles 1 6 



11. Ash-coloured sands 10 



12. Argillaceous sands 4 



13. Dark-grey clayey sands 11 



14. Bed of angular green-coated flints... 2 — 



15. Chalk with flints 119 6 



16. Hard chalk without flints 8 



17. Chalk, less hard, with few flints ... 31 6 



18. Nodular chalk, with three beds of 



tabular flints 13 6 



19. Chalk, with seams of tabular flint 



and a few nodular flints 32 6 



20. Chalk, with a few flints and some 



patches of sand 9 6 



21. Very light-grey chalk, with a few 



flints 30 



22. Light-grey chalk, with a few thin 



beds of chalk -marl subordinate... 133 



23. Grey chalk-marl, with compact and 



marly beds and occasional pyrites 161 



324 6 



Chalk-marl 

 (47 ft. 6 in.). 



24. Grey marl 20 



25. Harder grey marl, rather sandy and 



with occasional iron-pyrites 27 



,26. Hard rocky marl 6— 910 6 



Upper [" 27. 

 Greensand < 

 (72 ft. 6 in.), t 28. 



Bluish-grey marl, rather sandy ; the 



lower part more argillaceous 58 9 



Dark-green sand, mixed with grey clay 13 9- 



983 



Gault . 

 (130 ft. 6in.).^ 



' 29. Bluish-grey micaceous clay, slightly 



sandy 39 



30. Ditto, with two seams of argillaceous 



greensand 6 7 



^ 31. Micaceous blue clay 84 11—1113 6 



[continued at p. 14. 



