196 Mr. J. Phillips on the Geology of Havre. 



a mile from the town, clay, full of Gryphaea nana, M. C, is 

 dug beneath the sand of the beach, for the fabrication of bricks 

 and hexagonal tiles, which are white within, and only partially 

 reddened on the surface by the flame passing over them. 



Haifa mile bej'ond, the chalk hills are separated from the 

 sea by a buttress of chalk rubble resting on green and ferru- 

 ginous sands, in which I found a shark's tooth, small Terebra- 

 tula, and fragments of Inoceramus. These materials, in a state 

 of confusion, lie in the cliff against the sea, upon some of the 

 lower pale beds of the Kimmeridge clay, alternating with thin 

 layers of ochrey stone. 



The clay contains abundance of Gryphsea nana, and of an- 

 other small species with striated valves. Some specimens of a 

 quadrate Serpula, Rostellaria composita?, smooth Terebra- 

 tula spines and plates of Cidaris, Cucullaea,Amphidesmarecur- 

 vum [Phil.], Trigonia costata, Pholadomya, Isocardia? Te- 

 redo, Inoceramus. 



In the alternating layers of stone we find Rostellaria com- 

 posita, Amphidesma recurvum, and A. securiforrae [PJiil.), 

 Ostrea gregarea (a coarse variety exactly like one in the co- 

 ralline oolite at Sinnington, Yorkshire), Melania Hedding- 

 tonensis, M. striata. 



A similar series of stony layers, containing some fossils of the 

 coralline oolite formation, occurs near the bottom of the Kim- 

 meridge clay, in North Wilts, and in the Vale of Pickering. 



Further on, these beds rise a few feet into the cliff, and still 

 lower portions of the blue clay appear, inclosing one continuous 

 layer of Ostrea deltoidea (Sow.), and beneath this more com- 

 pact clay,with abundance of casts of the shell which he callsMya 

 depressa. Above all these layers of clay and stone lies a mass of 

 much darker clay, apparently more sulphureous, with nodules 

 of argillaceous ironstone, as at Speeton in Yorkshire, but with- 

 out any marks of the Astacidae, which are common there. Upon 

 this lies a confused heap of brown sand and blocks of white and 

 greenish sandstone, which have fallen from the neighbouring 

 steeps, and constitute a sort of undercliff. 



In the steep cliff which rises above this mass of fallen sand- 

 stones we see the chalk, resting on about thirty feet of green 

 and gray sand, and this reposing on the uppermost part of 

 the argillaceous series before noticed. The line of division 

 between the clay and the sandstone is pretty clearly marked, 

 but that between the green-sand and the chalk is almost ima- 

 ginary. On close inspection the mouldering surface of the 

 sand, and the pale hue of its layers of chert, serve to point out 

 its extent, and to distinguish it from the firmer chalk with 

 its more decided bands di Jiint', but at the junction these cha- 

 racters 



