OlSr THE CEETACEOUS BEDS AT BLACK VEN, IS'EAK LY3IE KEGIS. 23 



3. The Cretaceous Beds at Black Ven, near Lyme Kegis, luith some 

 SUPPLEMENTARY Eemarks oYi tJis Blackdown Beds. By Eev. 

 W. Doavnes, F.a.S. (Read November 5, 1884.) 



Four visits, each of three or four hours' duration, to the same 

 section and upon almost consecutive days ought to afford the 

 opportunity for recording somewhat, unless the section be either 

 one that is void of interest, or already so worked-out as to leave 

 nothing further to be recorded. In the present case, when among 

 the previous workers are found the names of Etheridge, Meyer, 

 De E-ance, Price, and others, it may seem probable that the subject 

 might have been exhausted. As, however, the writer's experiences 

 do not quite agree with all that has before been written, and as he 

 found not a few fossils in a bed hitherto (as he believes) supposed 

 to be non-fossiliferous, a brief memoir may be of service. 



The section in question is about halfway between Lyme Eegis 

 and Charmouth, in the sea-cliff. Four years ago there had been 

 a landslip there, which necessitated a reconstruction of the high 

 road. According to a local informant this landslip revealed for the 

 first time the presence of a bed of Gault ; but this statement was 

 certainly erroneous, for fossils from the Gault bed seem to have been 

 in the Jermyn-Street cases long ere that date. But the landslip 

 seems to have done some service to geology in making the Gault bed 

 in one place more accessible, and in causing a new and clean-cut 

 section of the beds above it to be made in the course of the recon- 

 struction of the road. 



The whole cliff-section may be roughly computed to be 300 ft., 

 of which the lower 200 ft. is Lias, and the upper 100 ft. is Cretaceous. 

 The latter may be subdivided again, as 25 ft. of black loamy clay 

 at the base, and above it 75 ft. of yellow non-calcareous sand, with 

 a capping of chert gravel. Further westward the Greensand is 

 calcareous, bat not at this spot. The Gault is of very much the 

 same colour as the Lias beneath ; but as the former is pervious, 

 and the latter impervious, it appeared to be more easy to trace the 

 boundary with the eye than to traverse it with the feet ; for in the 

 few places where a ledge is accessible there is a quagmire of black 

 slush, the result of the outbreak of springs. 



Mr. De Eance, as quoted by Mr. Price (' The Gault ' &c. p. 27), 

 tells us that, " at Black Ven, where it {i. e. the Gault) is best seen, 

 it is divided from the Cowstones above by a few feet of yellow sand. 

 A comparison of the fossils from this place with those at Folkestone 

 tends to correlate the Dorsetshire Gault with the Lower Gault of 

 Folkestone, rather than with the Upper Gault; in which case, sup- 

 posing the Whetstones in the Blackdown beds to represent the Cow- 

 stones, they and other portions of the former may be equivalents, in 

 time, of the Upper Gault." 



