50 GEOLOGY OF THE ISLE OF WIGHT. 



and other places lu Sussex, and near Sandgate,* thus obtaining 

 further evidence of the correctness of the correlations given above. 

 According to Mr. Meyer t the coprolite bed at RedclifF (de- 

 scribed on p. 37) corresponds to a pebble-bed at Godalming which 

 he considered to represent "a break in the hitherto continuous 

 deposition of the Greensand," and which he traced by Dorking, 

 Nutfield, and Maidstone towards Folkestone. This bed he took 

 as the base of his Folkestone Beds or upper division of the Lower 

 Greensand. It cannot, however, be followed through the Isle of 

 Wight, nor, when present, is it accompanied by any appearance of 

 a break. 



But while this line fails us, we find that the base of the Folke- 

 stone Beds, as drawn by the Geological Survey,J corresponds well 

 with the line at the base of the Sand-rock Series, which was inde- 

 pendently selected as a boundary capable of being traced through 

 the Isle of Wight. During the present year a brief visit was paid 

 to that part of the Lower Greensand outcrop in the Weald, which 

 lies nearest the Isle of Wight, for the purpose of comparing the 

 strata in the two areas, the result being to confirm in every par- 

 ticular the conclusions arrived at by Fitton. Lithologically, the 

 brightly coloured clean quartz-sands of the Folkestone Beds at 

 Pulborough, Midhurst, and Petersfield closely resemble the Sand- 

 rock Beds of the Isle of Wight. In both Sussex and the Isle of 

 Wight, moreover, these sands pass down into a group in which 

 beds of shale are conspicuous, and which is more evenly bedded 

 and more mixed with loam than the Folkestone Beds.§ At 

 Pulborough a band of shale, 30 feet thick, and taken by 

 Mr. Gould as forming the top of the Sandgate Beds,|| corre- 

 sponds closely in character and position to the thick clay-band of 

 Blackgang Chine, and of the railway cutting near Shanklin, 

 described on p. 46. The identification on the mainland, however, 

 of the rock now mapped in the Isle of Wight under the name of 

 Carstone is attended with some difficulty. The description of 

 this rock and its probable relations will form the subject of the 

 succeeding chapter. 



The great development of beds of corresponding age on the 

 Continent has been pointed out by Professor Judd,^ of whose 

 conclusions the following is an abstract. The Rhodanien of 

 Switzerland, which forms a complete link between Upper Neoco- 

 mian {Apticn) and Middle Neocomian ( Un/onien), has been shewn 

 by M. Eenevier** to be the equivalent of the Perna Bed, Athevfield 

 Clay, and Crackers of the Atherfield section. Among the fossils 



* Qiiart.Jour. Geol. Soc, vol. iii. p. 31L 1847. See also Geology of the 

 Weald (Geological Survey Memoir), pp. 136, 137. 



t On the Lower Greensand of Godalmiug {Proc. Geol. Assoc), 1869, p. 10. 



j Geology of the Weald (Geological Survey Memoir), 1875, pp. 138-144. 



§ The difference is greater than appears at the first view of sand-pits in the 

 two subdivisions. The Folkestone Beds are used commercially for building sand, 

 the Sandgate Beds for moulding purposes. 



II Geology of the Weald, p. 13C. 



•P" Quart. Journ. Geol. Soc., vol. xxvii. pp. 223-5. 1871. 



** Bull, de la Soc. Geol. dc France, 2me ser. tome xii. p. 89, 



