ISLE OF WIGHT AND LONDON BASINS. 295 



parts of England ; one he names the Isle of Wight Basin, 

 the other the London Basin. 



1. Isle of Wight Basin. 



The southern side of this basin extends from the high- 

 ly inclined chalk at the Culver cliffs, at the east end of 

 the Isle of Wight, to White Nose, in Dorsetshire, five 

 miles west of Lulworth. The north side of it may be 

 traced in that range of hills called the South Downs, ex- 

 tending from Beachy Head, in Sussex, to Dorchester, in 

 Dorsetshire. The strata of which these hills are com- 

 posed, dip generally from 15 to 5 to the south ; the in- 

 clination varying in different places. The south side of 

 the basin, therefore, must have been extremely steep, 

 while the slope of the north side was very gentle. The 

 closing of the basin at the west cannot be distinctly 

 traced ; but the east is now entirely open, the sea passing 

 through it. 



2; London Basin. 



The south side of the basin is formed by a long line of 

 r,halk hills, including those of Kent, Surry, Hampshire, 

 called the North Downs, extending through Basingstock 

 to some distance beyond Highclere Hill, in Berkshire. 

 Its western extremity is much contracted, and seems to 

 lie somewhere in the vicinity of Huagerford. Its north- 

 western side is formed by the chalk hills of Wiltshire, 

 Berkshire, Oxfordshire, Buckinghamshire,, and Hertford- 

 shire. The most southern part of this boundary has not 

 yet been well determined. On the east it is open to the 

 sea, the coasts of Essex, Suffolk, and Norfolk, being sec- 

 tions of the strata deposited in it. The dip of the chalk 

 of the North Downs, from Dover to Guilford, is from 

 15 to 10; but in the narrow ridge of chalk, called the 

 Hog's Back, extending from Guilford to Farnham, the 



