168 GEOLOGY OF THE ISLE OP WIGHT. 



strata, owing to its general creamy-white hue, and the angular 

 fracture of its beds. When closely inspected it is found to 

 consist of a number of distinct strata varying somewhat in thick- 

 ness in different parts of the bay, and yielding different measure- 

 ments to observers in different yeu-s, owing to the occasional 

 swelling out of the individual beds. Tlieir mutual relations and 

 distinctions seem, however, to be tolerably constant at this locality. 

 In the cliff, not far from the hotel, the Limestone rises from 

 the shore with a rapid and sudden curve ; its uppermost portion 

 inclining at a high angle. The best point for examination will 

 be found where the great curve of the limestones first reaches 

 the shore, and where these strata are exhibited in their entirety 

 with perfect clearness. Here this division of the Bembridge 

 group is composed of the following elements : — 



Bembridge Limestone at Whitecliff Bay (Measured in 1856 by 

 Professors Ramsay and Morris and H. W. Bristow). 



Feet. 



Hard white crumbly marl, with a few concretions and scattered 

 shells, and becoming harder and more shelly for the lower 

 () inches. Throws out water at the top. Planorbis discus, 

 Limntea in places. Passes gradually ijito the bed below. This 

 is No. 6. of Professor Forbes' section (see below) - - 2J 



Hard, compact, very shelly limestone, sometimes forming two beds, 

 with a harder and darker-coloured parting between. Chara 

 tvherculata and Ch. sp. — very abundant. Paludina orbicularis at 

 2 feet from the top. Limncea, Planorbis discus, Planorbis - 5 



Hard bed of compact sandy limestone, weathering white; plant- 

 like markings. Limncea (a few) ; Paludina (sm. sp.) - - 1 



Dark grey and carbonaceous clays, laminated with sand in the 

 lower part ; light green in the upper 2 feet, where they are 

 compact and marly, and sejjarated from the lower 12 inches by a 

 band of Cyrena obtusa with both valves joined - - 3 



Cream-coloured cavernous limestone, with a hard brecciated con- 

 cretionary cap, (5 to 9 inches thick, on the top of the bed, which 

 weathers to a very irregular surface. Limncea, numerous 

 Taxites and Planorbis (sm. sp.), Chara tuberculata, especially 2 feet 

 from the top. Emits a bituminous odour when struck - - 4 to 6 



Soft, white, earthy limestone, with a few casts of shells ; Planorbis, 



Limncea, Fish ....... 2 



Concretionary cream-coloured limestone, with an uneven surface 

 above and below ; weathering irregularly, and emitting a bitu- 

 minous odour when struck. Chara, Limncea longiscata - - 4 or 5 



Another section measured in 1853, near the same spot, by 

 Professor Forbes and Mr. Bristow is interesting for comparison 

 with the above, as it shows how the strata vary. 



Bembridge Limestone in Whitecliff Bay (1853). 



6. Crumbly white marl, with small globular concretions. Chara tuberculata 

 has its uppermost limit apparently in this bed. Planorbis obtusus is common 

 in it, but, like all other shells in the Bembridge limestones, is almost always 

 in the condition of a cast. 2 ft. 7 in. 



