LOWER CRETACEOUS STRATA. 153 



lime embedded in a paste of green grains of glau- 

 conite and marl, which entombs the most remark- 

 able lage of fo— ded by any forma- 

 tion in Britain. 



When this bed is traced north it is lost ; and in 

 so i an be judged from physical evidei 



and 5, IS :.. rgC I in the Hunstanton 



linm i hich divides in: thin beds. The 



middle :' that rock formed of 



con- - At the base of 



chalk wolds the limestone augments from 4 

 feet at Hunstanton to a considerable thickness at 

 Speeton, w: eds become very irreg- 



ss in 

 to the white ^J~ 



chalk without 



1 ti graph 

 planes 1 



regular diffus 



of the red Col- Fto. 31.— PlMtof the stem of an Encrinite 



• n the Car- 



our in par.- !ld in lhe 



the Chalk Would .eensand. 



indi- 



that the colour has an organic origin. 



The success the Upper G id upon 



the I ^sequence of upheaval 



of the old land from which the Upper Greensand 



S derived, bringing the source of the sediment 

 nearer; so that it became coarser. The Gault at 

 Ware rests directly upon the Wen lock limestone. 

 A: I eshunt it rests n the purple Devonian 



mudstones. Therefore this eastern country of 

 England gives no evidence of having been sub- 

 merged during all the Secondary ages till the 

 Gault sea spread over it, and Gault was laid upon 



■ 



