32 OEOLOGY OF THE ISLE OF WIGHT. 



From the chalybeate spring eastwards the Sand-rock series is 

 ahiiost entirely concealed by the slipped Greensand and Chalk of 

 the Underclifi'. The upper beds of the series are seen in a bold 

 bluff between Eocken End and Knowles, and again in the lower 

 part of the cliff below Niton. Here a white sandstone also is 

 exposed above the beach, about 100 feet below, which seems to 

 be the third sand-rock of Fitton. The last exposure occurs in 

 Binnel Bay, where interlaniinated sands and clays are exposed at 

 the base of the cliff. From this point eastwards there is no 

 rock seen in place till we reach Monk's Bay at Bonchurch. The 

 description of the Carstone or uppermost sub-division of the Lower 

 Greensand of this nciglibourhood will be found on pp. 57, 58. 



Sandown to Bonchurch. 



The Atherjield Clay and Ferruginous Sands. 

 Thou"-h nearly the Avhole of the Lower Greensand is exposed 

 in this coast section, the beds are not so conveniently situated for 

 examination as at Atherfield, and have yielded far fewer fossils. 



The Perna Bed and Atherfield Clay rise from the beach near 

 Sandown Pier in a low cliff, but are concealed by buildings ; 

 nor is the former exposed now at low water, as seems formerly to 

 have been the case. The overlying beds consist of green grey 

 and brown sands, so far decomposed as to render the identifi- 

 cation of the groups of Atherfield impossible. But specimens 

 of Crioccrns were found by Captain Ibbetson in a quarry, not 

 now identifiable, near the shore between Small Hope Chine (the 

 north end of Shanklin sea-wall) and the Barrack Hill, Sandown. 

 The horizon would seem to correspond approximately with that 

 of the Crioceras ranges of Whale Chine. Some o\'. the sands 

 north of Little Stairs Point are very dark-coloured, and contain 

 small fragments of wood impregnated with pyrites. 



At Little Stairs Point a fault is clearly exposed, a rare circum- 

 stance in the Isle of Wight. The fault ranges about west-north- 

 west, and throws the beds down to the south. Soon after passing 

 this fault the beds assume a horizontal position, or nearly so, and 

 we meet with the first marked bed in the section. It consists of 

 ferruginous sandstone, studded with clusters of Exogyra sinuatu 

 and Ostrca frons {= (). prionota,) and identified by Fitton {op. cit. 

 p. 317), with part of his Second Gryphfea Group X. Above it 

 occurs a bed composed of alternations of dark slaty clay with 

 greenish sand, which Fitton recognised as his Group XIL At 

 the top of the cliff is an iron sand. 



Chalybeate water Issues from these strata. The spring known 

 as Shanklin Chalybeate Spa was first noticed by Dr. Fraser, 

 physician to Charles II. It has been analysed by Dr. A. H. 

 Hassall with the following result : — 



