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THE CRETACEOUS ROCKS OF BRITAIN. 
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Fig 54. —The Succession at St. Jouin. 
Scale 16 feet to an inch. 
ft. in. 
Greyish-white chalk, divided into courses by layers of 
cherts, which are bluish-grey inside - - 30 0 
Grey marly chalk 
Grey glauconitic chalk, often rough and gritty, with some 
black cherts and many brown phospliatic nodules - - 11 0 
Grey chalk, with hard calcareous lumps - - - -20 
Greyish-white chalk, slightly glauconitic, with layers of 
grey or black cherts • • • . • ■ • - 11 0 
Yellowish-grey chalk, with hard calcareous lumps - 2 6 
Yellowish-grey glauconitic chalk, with many grey cherts, 
both scattered and in layers, and also hard calcareous 
masses -----.12 9 
Greyish-white shelly chalk, with calcareous lumps ; some 
grey cherts in the middle part.7 6 
Hard grey chalk, with a layer of green-coated nodules at 
the top - -- ..33 
Grey glauconitic chalk, with two layers of cherts; the 
lower very large.3 9 
Yellowish-white, slightly glauconitic chalk, with courses 
of cherts at intervals.- 13 0 
Bluish-grey marly chalk 
Buff-coloured chalk, streaked with bluish-grey, with 
courses of cherts at intervals.- 10 0 
Bluish-grey, marly, glauconitic chalk, with hard calcareous 
lumps - . 3 0 
Buff-coloured chalk, with four courses of black cherts - 5 0 
Soft grey glauconitic sandy marl, with many black phos- 
phatic nodules.‘ - * 3 
Grey sandy glauconitic marl (Gaize). _ _ 
120 0 
