130 GEOLOGY OF THE ISLE OF WIGHT. 



The freshwater series next appears ; but in the 

 lowermost division of this group there is an inter- 

 mixture of estuary and marine shells; these de- 

 posits would, therefore, he more correctly desig- 

 nated flmio-marine. Calcareous marls, sandstones, 

 and limestones, abounding in fluviatile and lacus- 

 trine shells, similar to those of Binstead, form the 

 succeeding portion of the cliff. On a recent visit 

 the fallen masses of rock were full of fossil seed- 

 vessels of chaxae (C. tuberculata, lign. 5, p. 109). 

 Some of the upper strata are of a fluvio-marine 

 character, and within 100 feet of the superior layer, 

 there is a seam of oyster-shells in a bed of marl 

 near the top of the cliff at Bembridge-ledge, which 

 was pointed out by Mr. Lyell in 1824. 



There are several layers of pebbles in the marine 

 vertical strata ; and in some of the calcareous 

 sandstones of the upper series, pebbles and an- 

 gular fragments of flint are imbedded, alternately 

 with seams of freshwater shells. 



The total thickness of the eocene strata at 

 Whitecliff Bay is about G50 yards ; * of which, 

 according to the measurements of Mr. Prestwich, 

 the mottled clays are 142 feet; the Bognor series 

 about 300 feet; the London clay 9o0 feet: and 



* Where the beds are vertical, the horizontal distance of com i 

 tm thickness of the deposits. 



