THE GREENSAND. 189 



and Bonchurcli ; I believe only a few fossils have 

 been observed. 



The greensand. — This division of the creta- 

 ceous s} r stem comprises numerous alternations of 

 argillaceous and arenaceous strata of great thick- 

 ness and extent, constituting an important group, 

 which is well defined by the fossil remains. 



It consists of cherty and calcareous sandstones, 

 and sands of various colours, white, green, grey, 

 red, brown, fawn, yellow, and ferruginous : the 

 predominance of the green sands in some districts 

 having suggested the term now employed to de- 

 signate the group. It was called the iron-sand 

 where the ferruginous character predominated, as 

 in the Isle of Wight.* Thick beds of sandy and 

 ferruginous clay, are intercalated with the arena- 

 ceous strata. The Greensand is separable into 

 three divisions, as was first shown by Dr. Fitton, 

 whose indefatigable and successful labours have 

 so largely contributed to the elucidation of the 

 characters and relations of the deposits between 

 the chalk and oolite in England. 



In the upper or Shanklin sand series, the strata 



* The whole series is described by Mr. Webster, as the Iron-Sand, in his 

 various memoirs on the geology of the Isle of Wight; and the unfortunate 

 application of this term to the sands of the Wealden districts of Surrey, 

 Kent, and Sussex, retarded, for a long period, the true exposition of the 

 nature and relation of those deposits. 



l2 



