368 Dr. Fit ion on the Strata [Nov. 



The annexed map and section (Plate XXXIII, fig. 2,*) will 

 show the relative situation of the strata, and will explain the 

 circumstances which render the exterior of the low •country, at 

 the back of the Isle of Wight, somewhat different in appearance 

 from that of Kent and Sussex, which it really does resemble. 

 The ridge of vertical chalk strata which traverses the whole 

 of the Island from east to west, is succeeded on the south by a 

 parallel range of low hills, consisting of sand, and separated from 

 the chalk by a narrow valley occupied by blue clay : this lower 

 range resembles both in composition and relative place, that 

 which occurs between the chalk hills and the Hastings sands, 

 throughout the greater part of Kent and Surry; and near the 

 coast of the island, it is succeeded by a still lower tract, denoting 

 the situation of the weald clay — from beneath which, as in Sus- 

 sex, the Hastings-sands rise distinctly near Brook Ledge, and also, 

 but less obviously, in Sandown Bay. If, where the chalk recurs 

 in the south of the island, its inclination had been similar to that 

 of the central beds, we should probably have had between the 

 two chalk ranges a parallel ridge of iron sand, with a succes- 

 sion on both sides of similar beds in the same order ; and the 

 section of the coast at the back of the Isle of Wight, 

 both on the south-west, from Convpton Bay to Rocken End, 

 and on the south-east from Chine Head to Culver, would have 

 corresponded exactly to that of the shore between the cliffs of 

 Dover and Beachy Head. (Fig. 1.) But the southern platform 

 of chalk being nearly horizontal, — its distance from the central 

 ridge inconsiderable, and the outcrop of the two ranges not 

 parallel but converging towards the interior, the beds of sand 

 which come from beneath it, meet the corresponding strata which 

 rise from under the central chalk, so as to conceal the lower 

 beds of the series. It is, therefore, only where the streams have 

 cut deeply through the surface, or on the coast, where the 

 upper strata have thinned out, that the Hastings sands can 

 make their appearance ; and when they do oceur upon the 

 shore, their section exhibits lines of unequal curvature, with the 

 greater inclination, on both sides, next to the central ridge of 

 chalk. 



In looking westward from the heights above Rocken-End, 

 the structure now described is plainly discernible : — the Green 

 sand thins off gradually to Atherfiejd Point, but forms in the 

 interior a continuous range of low 'hills from Walpen Chine 

 to Kingston, on the west of which place are some eminences of 

 sand ; and from thence the range of sand hills already men- 

 tioned can be traced without interruption to the shore at 

 Compton Bay. The low country of the weald clay is also seen 



* This map is reduced from the ordnance survey, coloured after Mr. Webster, with 

 the necessary alterations on the coast ; the general relations of the strata being the object, 

 accuracy of local detail has not been attempted. 



