Chalk Cliffs on the Coast of France . 49 
west of that place. The grey chalk forms the base of the principal 
part of Cape Blanc Nez, and of the centre of Petit Blanc Nez. A 
blue marie forms the base of the latter. The junction of the marie 
with the grey chalk is well defined. The marie has a perfect re- 
semblance to that which forms the summit of the cliff between 
Copt Point and Folkstone, contains similar organic remains in great 
plenty, together with so vast a quantity of iron pyrites, that works 
have been established near St. Pot for the manufacture of green 
vitriol. 
Small masses of a green sandstone, similar to that lying in the 
sand which forms the base of the cliff between Copt Point and 
Folkstone, are scattered along the shore at the foot of the chalk 
cliff. I expected therefore to find it underlying the blue marie. 
But the latter, owing in part to the looseness of its texture in dry 
weather, in part also perhaps to its having been turned over in 
search of iron pyrites for the vitriol works, forms the whole of the 
low bank near St. Pot ; between that bank, however, and the sea at 
low water, lies a large assemblage of green sandstone rocks, many 
of which appear to be in situ; so that no doubt can be entertained 
of its underlying the blue marie. The latter terminates near 
St. Pot, and is succeeded by a loose white siliceous sand for a 
considerable distance on the west ; but the sand and marie are for 
some little way intermingled. 
While viewing Blanc Nez from the base, it is readily observed, 
that the stratum consisting of numerous thin beds of organic re- 
mains which forms its centre, is separated from the superincumbent 
stratum, which is much whiter and softer, and on which few traces 
of organic exuviae appear, by a thin crevice, indicating the presence 
of a bed of chalk-marie. In this softer chalk, dispersed flints are 
visible, and are readily cognizable by the assistance of a glass, 
Vo L. V. G 
