556 S. Keeping — The Age of the Creechbarrow Limestone. 



reason for the form of Creechbarrow Hill, and the outline suggests 

 that it is due to some hard bed near the top, which we find on close 

 examination to be a tough limestone, a considerable portion of which 

 is hard and porcellaneous. The upper beds of this conical hill, 

 which rises to a height of 637 feet above sea-level, are cut off from 

 the adjoining masses, and therefore no continuous section can be 

 traced to the well-known formations on the south or on the north. 

 The section is further complicated by the occurrence of faults on 

 both the north and south sides. We have, therefore, only the 

 lithological character and fossil contents to depend upon for the 

 correlation of the beds occurring in this outlier. 



Mr. W. H. Hudleston has described the section at some detail 

 in this Magazine,' and although he admits that the Creechbarrow 

 Limestone resembles the Bembridge Limestone in some respects, 

 he comes to the conclusion that it belongs to the Bagshot Series. 

 Mr. Strahan ^ suggests the possibility that it may be the equivalent of 

 the Bembridge Limestone. Mr. Hudleston speaks of the " thoroughly 

 exceptional character of Creechbarrow in relation to the rest of 

 the Tertiary beds in the neighbourhood", and quotes a workman 

 who said " that Creechbarrow bulges all these beds and throws 

 them out of line". But in his summing up he states "we cannot 

 say what the hill itself consists of". 



As I have stated above, the Survey has drawn faults on the 

 north and on the south side of the outlier, and an over thrust is 

 known to occur in close association, also there is room for un- 

 conformities between the Lower Tertiary and the Freshwater Series. 

 I do not propose to discuss the structure, or to choose between 

 faults, overthrusts, and unconformities. I merely wish to express 

 the opinion that however it got there this limestone of Creechbarrow 

 Hill is the equivalent of the Bembridge Limestone, and not of any 

 part of the Bagshot Series, upon which it must rest discordantly. 



After over sixty years of practical experience of this formation 

 I hope it will be considered that I should know a piece of Bembridge 

 Limestone, having worked it at the following places — Headon 

 Hill, Cliff End, Sconce, . Hampstead Point, Gurnet Bay, Binstead 

 Quarries, St. Helens, Bembridge, and Whitecliff Bay. I know of no 

 limestone in the Bagshot beds agreeing with the Creechbarrow Lime- 

 stone in lithological character or fossil contents, but in the Bembridge 

 Limestone we have the same kind of rock passing down in the same 

 way through nodular concretionary beds into the underlying clay 

 series. 



In the Bagshot beds I know nothing resembling the lime-coated 

 Paludina or Melanopsis, to whatever genus and species the Creechbarrow 

 specimens may be referred. The remarkable fossil which has long 

 been referred to as a cocoon, or the egg, first of turtle, and later of 

 Bulimus, occurs at Creechbarrow, and if the shell of Bulimus could 

 have been found I think the identity of the Creechbarrow and 

 Bembridge Limestones might be considered proved. Seeing, therefore, 



1 New Ser., Dec. IV, Vol. IX, June, 1902, p. 241; Vol. X, April and May, 

 1903, pp. 149, 197. Proc. Dorset Field Club, vol. xxii, p. liv. 



- " Guide to the Geological Model of the Isle of Piu'beck" : Mem. Geol. Survey. 



