146 



LOCAL SCIENTIFIC NOTES AND MEMORANDA- 



PURPLE-GREY CARBONIFEROUS ROCKS AND THE 

 WHITEHAVEN SANDSTONE. 



In Part IX. of our Transactions I made some remarks on the 

 Whitehaven Sandstone,* and incidentally criticised a paper of Mr. 

 J. D. Kendall's, in which he appeared to me to assume that 

 tPurple-Grey Carboniferous rocks were necessarily of Whitehaven 

 Sandstone age, though, as I pointed out, they occur on almost 

 every horizon throughout the Carboniferous series in Cumberland. 

 My contention was, consequently, that purple-grey rocks should 

 not be assumed, on the mere ground of colour, to belong to the 

 Whitehaven Sandstone group, and, like it, to lie unconformably on 

 the Carboniferous beds beneath. That geologists had for many 

 years recognised the unconformity of the Whitehaven Sandstone, 

 but that actual evidence of unconformity was necessary before it 

 became safe to infer that the purple-grey rocks of any given locality 

 were of that age. In illustration, I referred to Mr. Kendall's sheet 

 of vertical sections, pointing out, with regard to those of BuUgill 

 and Aspatria, that, looked at without theoretical preconceptions, 

 their general correspondence seemed to make the relegation of the 

 greater part of the latter to the Whitehaven Sandstone series an 

 vmsound determination. 



Mr. Kendall, in his reply (Part X.) agrees with me that "mere 



* pp. 113— 117. 

 + Proc. N. Eng. Inst. Min. Eng. Vol. xxxii. p. 319 (1S83). 



