72 GEOLOGY OF THE ISLE OF WIGHT. 



the anticlinal position of the Wealden ; the chalk of 

 the South Downs, clipping southwards, with tertiary 

 strata on the southern flank: then the depression 

 which forms the channel of the Solent sea; the 

 tertiary strata extending over the northern portion 

 of the Isle of Wight ; the chalk downs of the island, 

 dipping northward ; and, lastly, a small portion of 

 Wealden, emerging from beneath the chalk, on the 

 south coast, at Brook and Sandown bays. 



London and Brighton railway section. — 

 A portion of this section is w T ell displayed along 

 the line of railway from London to Brighton. 

 Leaving the station at London-bridge, the tertiary 

 clays with their characteristic fossils, are seen from 

 beyond Deptford, by New Cross, Sydenham, &c. ; 

 and approaching Croydon, beds of gravel appear, 

 with interspersions of olive-green sand. The valley 

 beyond Croydon, along the side of which the 

 railway proceeds, is a thick bed of gravel resting 

 on the chalk. Beyond the station called Stoats 1 - 

 nest, is a fine section of the chalk with Hint, and 

 the North Downs are traversed by a long tunnel 

 carried through the solid chalk, and emerging 

 near Merstham, where the firestone and marl 

 rise to the surface. The sands and clays of the 

 chalk are passed at the Red-hill, and Godstone 

 stations, and the Wealden clays appear, and at 



