216 GEOLOGY OF THE ISLE OF AVIGHT. 



A small outlier caps the highest part of the hill near Norton- 

 green, apparently unconnected with the present valleys. 



Headon Hill. 



Another outlier, on Headon Hill, is perhaps the most puzzling 

 cf auy. It reaches a height of 390 feet, but is separated from 

 the Downs by a deep valley, and is cut off on the west and north 

 by sea-cliffs. The gravel is exceptionally thick, appearing some- 

 times to measure 30 feet. It is composed of unworn flints and 

 sand with pieces of ironstone, but no chert or foreign rocks 

 could be found in it. 



Wootton BiHdge to Ryde. 



Keturning to the East Medina, east of Downenci, we find no 

 trace of Plateau Gravel on the Tertiary area anywhere near the 

 Downs. The whole of the country through which the lines of 

 railway pass consists of low ground which has suffered great 

 denudation in more recent times. One gap through the Downs, 

 that through which the eastern Yar passes, is j^robably of ancient 

 date, but no gravels lie in it and the continuity of the plateaus 

 north and south of the Down is lost. It therefore only remains 

 to describe the belt of Plateau Gravel which ranges parallel with 

 the coast between Wootton and Bembridge. 



The outlier east of Wootton Bridge consists of partly rounded 

 flint and chert gravel, rising to a height of 170 feet towards the 

 south, but sinking below the lOO-foot contour on the north, and 

 below 70 feet tow^ards Ashlake. The lowness of the gravel to- 

 wards Ashlake, however, may be mainly due to a landslip which 

 has also affected the position of the Hamstead Beds. 



East of the outlier just described, the character of the gravel 

 changes in a marked manner, and the beds have all the appear- 

 ance of true beach-shingle. The first pits in which this character 

 presents itself occur close together south-west of Binstead Lodge. 

 The Ivyde outlier evidently consists of similar materials, though 

 at present no sections of it, can be seen. 



Ryde and St. Helens. 



The large sheet east of Small Brook deserves special study, 

 for the sections are curious and some of the pits may ultimately 

 yield fossils. The southern and eastern branches of this mass 

 show no sections, but well-worn shingle is seen in the fields. 

 The western branch descends to within about 30 feet of the sea- 

 level and shows fine sands like those of Ruffin's Copse. Close to 

 Preston in a large brick-yard and gravel-pit the subjoined section 

 may be seen : — 



Feet. 

 Shingle and mottled clay, contorted together - 2 to 6 

 Fine sand with seams of loam and scattered 



flints ----- 9 



