Denudation. 347 



the Isle of Purbeck they stand nearly on end. Those 

 who are familiar with the Isle of Wight will remember 

 that from east to west, or from White Cliff Bay to 

 Alum Bay, there is overlying the Lower Greensand g, 

 a long range of Chalk hills, c, the strata of which dip 

 towards the north, and are overlaid by the older 

 Tertiary strata e, that is to say, the Woolwich and 

 Eeading beds, the London Clay, the Lower Bagshot 

 Sands and Clays, the Bracklesham Beds, the Upper 

 Bagshot Sands, and all the higher freshwater and 

 estuarine divisions e, as enumerated in the column p. 30, 

 and in the diagram, p. 241. 



The whole pass under the Solent, as shown in the 

 lower dotted lines e e, fig. 74, and rise again on the 

 mainland in Hampshire, a considerable portion of which 

 is composed of various subdivisions of the Eocene rocks. 

 The same general relations of the Secondary and Eocene 

 strata are seen on the mainland in the Isle of Purbeck, 

 at and west of Swan age, as shown in the following section 

 north of Kimeridge Bay (fig. 75). 



FIG. 75. 

 /Section across the Isle of Purbeck. 



1. Kimeridge Clay. 2. Portland Oolite sand. 3. Portland 

 Oolite limestone. 4. Purbeck limestone and marls, chiefly 

 freshwater beds. 5. Weald sands and clay, freshwater. 6. 

 Neocomian and Grreensand. 7. Chalk without flints. 8. 

 Chalk with flints. 9. Woolwich and Eeading beds. 10. 

 London Clay. 11. Bracklesham and Bagshot beds. 



Now these disturbed strata of the Isle of Wight were 

 deposited horizontally, and after disturbance, the Chalk, 

 c, spread over an extensive area of Lower Grreensand, 



