370 Rev. W. B. Clarke on the Geological Structure 



Feet. 

 Brought forward.. 20 



4. Lower London clay — ten layers of green pyritous clay each 1^ inch" 



thick in blue clay 



5. blue clay, thin seam 



6. two layers of green pyritous clay ^ 20 



7. blue clay with limestone 



8. do. with two layers of pyritous green clay . 



9. blue clay J 



Total . . 40 



In 1834 Dr. Mitchell found the height diminished five feet, and no traces 

 of crag. The slope of the cliff to Harwich shows that it was once much 

 higher ; if continued to the "west rocks", the height would perhaps be about 

 100 feet, — the probable greatest height attained formerly by the coast from 

 HoUesley Bay to Walton Gap. 



No. 6. Harwich, well made in West Street, and discontinued. 



Ft. In. Ft. 



1. Diluvium — earth 3 



2. sand (salt spring) 12 



15 



3. London clay — " platamore" 9 



4. Plastic clay — shingle and gravel 12 



5. red sand 9 



6. coarse gravel 6 



7. coarse dark sand 9 



8. green and red clay interspersed 1 6 



9. green clay 2 6 



40 



10. Chalk — containing pyrites and echini 30 



11. do. and a peculiar white sand 10 



40 



12. Chalk marl — grey chalk, with shells 72 



1 3. chalk marl (50 



14. Boring continued 121 o 



253 



Total.. 357 



No. 7. New boring, Harwich, commenced 1826, discontinued 1827, 

 70 yards north of No. 6. 



1 . London clay — greyish marly clay 70 



2. Plastic clay — compact clay, beautifully mottled red and lilac 10 



3. fine sand, with water containing 4 per cent, muriate of soda . 8 



— 18 



4. Chalk 192 



Total.. 280 



