I ,s 



THE STOKY Ol 1 HE EARTH. 



I v mian; because, although they ex- 

 hibit a threefold division, it is difficult always 

 prove that these parts correspond to the Portland 

 ami Purbeck, Weald, and Lower Greensand re- 

 spectively. In the Isle of Wight, the Lower 



ensand consists i)\ a large number of alter- 

 nating beds of sand and clay, more than 900 feet 

 thick. More than eighty distinct layers have 

 been grouped into sixteen beds. So that the 

 conditions of deposition of the Weald seem to 

 have continued through the succeeding epoch of 

 time; and occasionally the remains of an J^inin- 

 odon became floated into the Lower (ireensand 

 from land diminished by depression of its level. 

 There is the same correspondence oi the Lower 

 (ireensand to the W'ealden beds in stratigraphical 

 Succession in the typical W'ealden area of Sussex. 

 The Lower Greensand is divided, in the section 



1 1 ,. .■; -Section from Folkestone i<» Hythe, showing above the 

 fresh-water Weald Clay, the <liviM<>:is ,,t" the marine Lower 

 ensand, named Atnerfield beds, Hythe 



be Is, I ■ »lkest< >ne I n 



. Hythe and Folkestone, into the Ather- 

 I Clay at the base, which is sometimes a ma- 

 rine esting '»n the Weald Clay, and some* 

 c sharp sand. Secondly, the Hythe 



beds (or Kentish rag) are alternations <>f thin 



bedded limestone and sand with beds of chert. 



Thirdly, the Sand-ate beds a:c sandy cl 



at, often green, like the underl] 



