178 A DELIMITATION OF THE CENOMANIAff. [May 1 896, 



Chloritic Marl to the westward as younger than the easterly 

 exposures of the same. 



Mr. Strahan remarked that he was under a disadvantage in dis- 

 cussing the paper, through not having seen the Continental sections 

 referred to. It seemed, however, to be clear that English geologists 

 were having reason to repent the introduction of Continental names 

 into their Cretaceous nomenclature. He himself had always hesi- 

 tated in using the term ' Cenomanian ' from a doubt as to its precise 

 application in this country. The correlation was most important, 

 for the principal break in our Secondary rocks occurs at the base 

 of the Upper Cretaceous group. He enquired if a ' Carstone ' and 

 yellow sand which, intervened between the Gault and Kimmeridge 

 Clay at Cape La Heve were not the same as the ferruginous grit which 

 forms the base of the Gault in Dorset and elsewhere. Phosphatic 

 nodules occur in the Chloritic Marl and sporadically through the 

 Upper Greensand, and seem to be foreign to the matrix in which 

 they are embedded. The glauconitic grains, too, seem unlikely to 

 have been formed in the water which distributed the sands and 

 coarse grits. He asked the Authors whether they had any clue to 

 the deposits with which these materials had originally been associated. 

 In referring to Mr. Hill's Continental investigations, he congratulated 

 him on a fine piece of work. 



Dr. J. W. Gregory congratulated the Authors on the value of the 

 paper and the greater precision that they have given to a useful term. 

 The confusion in regard to the term ' Cenomanian ' is not so much a 

 case of hasty use of a foreign name in England, as of unsatisfactory 

 original definition of the term abroad. He fully agreed with the 

 Authors that echinoids are rather a clue to conditions of formation 

 of a deposit than evidence as to its exact contemporaneity in age. 



Mr. E. S. Herries hoped that, as a result of this paper, geologists 

 would use the term ' Lower Chalk ' in place of ' Cenomanian,' at 

 any rate when speaking of the English beds here described. 



Mr. W. Hill, in reply to the President, remarked that they 

 relied on the occurrence of tetrabranchiate cephalopoda to prove 

 the age of the beds, rather than on the fauna which must have existed 

 entirely on the sea-bottom. He thought that the Chloritic Marl of 

 the eastern sections was probably older than that more to the west- 

 ward. Beds 10, 11, and 12 were certainly seen as far as Branscombe 

 Cliff. He believed that the phosphatized fossils, which Mr. Strahan 

 suggested were derived, were not necessarily so, but might be of the 

 same age as the bed containing them. There were but few phos- 

 phatized fossils in the Chloritic Marl of La Heve ; and the fact that 

 this marl contained small quartz-pebbles and much sand seemed to 

 him evidence of current-action. He was prepared to admit that 

 the Carstone-like bed seen in the cliffs at Cape La Heve might be 

 of Gault age, and, in conclusion, heartily thanked the Eellows of 

 the Society, on behalf of Mr. Jukes-Browne and himself, for their 

 cordial reception of the paper. 



