WEALDEN BEDS. 5 



tified at various horizons in it.^ On the other hand the most 

 striking characteristic of the beds is their ehaly character, as com- 

 pared with the almost structureless variegated clays, and the name 

 of Wealden Shales will perhaps be sufficiently distinctive. 



The Wealden Beds rise from beneath the Lower Greensand in 

 Brixton and Sandown Bays, on the south-western and south- 

 eastern sides of the Island respectively. In both bays they rise 

 with a steep dip from beneath the rocks which compose the 

 central range of the Island. On receding from this central axis 

 of disturbance the angle of dip grows less, until the beds finally 

 assume a horizontal position, as may be seen near Brook, in Brixton 

 Bay, and in Sandown Bay at the point where the coast-line cuts 

 the Alluvium of Sandown Marsh. Still further south in each of 

 these bays a gentle southerly dip sets in, and the higher beds of 

 the Wealden series pass in succession below the beach. The 

 structure, therefore, is similar at each locality, namely, that of a 

 dome with a steep side to the north. 



Beook and Compton Bay. {See Plates II. and III.) 



The lowest beds displayed in the Island are those forming the 

 shore near Brook and at Sedmore Point, half a mile south-east 

 of Brook Chine.f At Sedmore Point a bed of sandstone forms the 

 foot of the cliff for about 400 yards. Above it are blue, purple, 

 and deep-]-ed marls, overlain about half-way up the cliff by an 

 impersistent bed of sandstone, with a gravelly band about 

 18 inches thick, made up of fragments of sandstone with 

 many small bones, at its base. Gyclas, Paludina, and Unio are 

 recorded by Fitton from this bed. The upper part of the cliff 

 consists of purple and blue marls, with light-coloured bands 

 containing much lio;nite. 



Between this Point and Brook Chine the strata have slipped, 

 forming an undercliff, known as Roughland, along the whole 

 length of which (some 500 yards) there is no clear exposure of 

 rock in place, though the extent of the slip shows that the beds 

 must be chiefly clays. As we approach Brook Chine the section 

 becomes clear again. A greenish band may be seen to rise 

 westwards from beneath the beach, and to run along the upper 

 part of the cliff past Brook Chine to a small chine 180 yards 

 south of Brook Chine, where it descends once more to the beach. 

 This bed is easily traced by its colour, and by the fact that it is 

 crowded with large flattened masses of lignite, especially to the 

 south and west of Brook Chine. It shows that the strata form a 



* Geology of the Weald (Geological Survey Memoir), and Drew, Quart. Journ. 

 Geol. Soc, vol. xvii. p. 283. 



t The local name for the deep fissures or gullies, •which are termed chines in the 

 Isle of Wight, is derived from the Anglo-Saxon cinu, a cleft, AVyclif speaks of the 

 " chync of a ston--wall." So also, Spenser — 



<' Wlii.ru bytiug decpe, so deadly it imprest. 

 That quite it chyned his backc behind the sell." 



— Faerie Queene, b. iv., canto 6, xiii. 



