THE ISLE OF WIGHT. 369 



eilling on the petals of a tulip. The coloured sands are 

 destitute of animal remains ; but seams of lignite and a few 

 vegetable impressions are found therein. A remarkable bed 

 of white pipe-clay is- intercalated with the sands, containing 

 beautiful impressions of the leaves of many dicotyledonous 

 trees. 



The Barton series contains shells identical in species with 

 those found so abundantly in the celebrated Barton Cliff, 

 on the opposite shore of the Solent. 



The upper and lower Freshwater beds are admirably 

 exhibited at Colwell Bay and Headon Hill, and the upper 

 Marine stage which is intercalated between the upper and 

 lower Freshwater beds, can be traced from the point where 

 it rises on the shore at Colwell Bay, and ascends in its 

 relative position in the cliff.* The beds at Alum Bay are 

 1664 feet thick, being about 311 less than those at White- 

 cliff. 



The Isle of Wight forms a highly interesting epitome of 

 the whole of the formations existing in the south-east of 

 England, comprising the marine tertiary deposit of the 

 London basin, with freshwater strata not occurring in that 

 locality, together with the various stages of the chalk, green 

 sand, gault, lower green sand, and neocomian, and the lime- 

 stones and sandstones of the wealden. 



THE PARIS BASIN. Having thus briefly described the 

 chief British localities in which the tertiary strata are 

 developed ; the basin of the Clyde ; the crag of Norfolk and 

 Suffolk ; and the basins of London and Hants ; we shall now 

 cross the Channel to inspect the more ample development 

 of these formations on the wider area of the continent of 

 Europe. It is a singular fact, that the capitals of England, 

 France, and Austria, are built on the tertiary strata. The 

 Paris basin extends over a large area, occupying a length, 

 from north-east to south-west, of about 180 miles, and a 

 breadth, from east to west, of about 90 miles. This space 

 may be described as a depression in the chalk, which has 

 been filled up by alternating groups of marine and fresh- 

 water strata. The entire series admits of the following 

 classification : 



* Dr. Wright on tlic Geology of the Isle of Wight. Annals of Nat. History, 

 vol. vii, page 87. -,~ . :. 



