214 GEOLOGY OF THE ISLE OF WIGHT. 



the gravel, is entirely devoid of fossils and appears to have been 

 decalcified. Various other pits have at different times been 

 opened in this outlier, but the only one at present worked is at 

 Little Lynn Common. At the cross roads further north the 

 gravel is said to be as much as 16 feet thick, though the usual 

 thickness is about 7 feet. 



The Whippingham and Osborne outlier occupies about two 

 square miles, but though the gravel sometimes reaches as much 

 as 20 feet in thickness, ridges of clay constantly rise through it, 

 and make the working very uncertain. A good section occurs at 

 Whippingham, and another above Norris Wood. The latter shows 

 over 10 feet of subangular gravel, more rolled and more distinctly 

 bedded than in the pits further south. From this sheet of gravel 

 the water-supply of Osborne is obtained. 



The Wootton outlier is similar to the one just described. A 

 large pit about a quarter of a mile west of Wootton Lodge, 

 shows 10 feet of worn flint and chert gravel. Another pit near 

 the northern end of the outlier gives a section of similar gravel 

 with numerous well-worn flint pebbles. 



Parhhurst Forest to West Cowes, 



West of the Medina, the gravels have the same general 

 northerly fall, combined with a slight inclination towards the 

 Medina. At the same distance from the Downs and from the 

 Medina, we find gravels like those near Downend, and at about 

 the same height. The outlier in Parkhurst Forest, at the Signal 

 House, is 260 feet above the sea ; the southern end of the North- 

 wood outlier is 213 feet and the northern end at 120 feet, giving 

 a fall of 140 feet in 3 miles, or 1 in 113. 



The outliers in Parkhurst Forest are a good deal worked, but 

 call for no special description. The Northwood outlier is much 

 more important, for not only is it extensively worked, but it has 

 also yielded till lately a sufficient supply of water for Cowes. 

 The principal pits are two near Northwood Church, both worked 

 to a depth of 13 feet ; Place Brick-yard, which shows 5 or 6 feet 

 of gravel overlying the clay ; a pit close to the cliff north-west 

 of Northwood Park and just above the 100-foot contour ; and a 

 pit at the east end of Tinker's Lane. These all contain gi'avel of 

 the ordinary character ; but a pit on the north side of Ruffin's 

 Copse, of crenler interest, shows : — 



Feet,. 

 GraA'el and mottled clay, mixed - - - - - 5 



Fine white sand with black specks, about - - - 10 



Gravel (now hidden), said to be - » - - 2 



17 



A trial boring made a few hundred yards further east, for the 

 ])urpose of testing the water supply, is said to have penetrated the 

 following deposits : — 



