478 ME. D. BELL ON THE SHELLT CLAYS [Aug. 1895, 



be produced at many points where the inland ice did not meeb and 

 coalesce with the northward-moving sheet along the coast. Into 

 these bodies of still, tideless water, the fine red mud, fragments of 

 shells, stones from a distance, etc., with which the ice was charged, 

 would be shed and gradually accumulate. 



Similar effects were produced elsewhere. Mr. Lamplugh haa 

 shown that as far south as Elamborough Head the ice had a thick- 

 ness of at least 500 feet, overriding the cliffs in many parts and 

 extending to some distance inland, across the mouths of the eastern 

 valleys. ' The drainage-channels of the streams flowing eastward,' 

 he says, ' were dammed by the ice, and lakes were formed wherein 

 deposits of gravel and other material rapidly accumulated.' 1 And 

 the observations of the present writer have led him to believe that 

 similar conditions existed also at Clava. 



It seems almost like an anticipation and confirmation of this 

 suggestion that the late Dr. John Fleming, of Edinburgh, — a shrewd 

 and sagacious naturalist, whom Mr. Jamieson quotes as having 

 ku own the Red Clay well, — 'thought it must have been accumu- 

 lated in the water of some immense lake into which the sea had 

 made only a temporary irruption.' This strikes us as being a re- 

 markable surmise of fifty years ago, when the distinguished author 

 had no idea, apparently, of how such a lake could be formed. 



The writer is pleased to add that Mr. Jamieson has courteously 

 acknowledged the probability of the conditions herein suggested. 



Discussion. 



Mr. Clement Beid said that, although unacquainted with the 

 particular district dealt with by the Author, he was inclined to- 

 agree with his explanation of the origin of the shelly deposits. The 

 tumultuous character and the mixed fauna of the Clava sands and 

 Boulder Clay agreed closely with what he had observed in other 

 glaciated districts at heights of over 150 feet. 



Prof. G. A. J. Cole remarked that the publication of the paper 

 would be looked forward to with great interest in Ireland, where 

 the extent of shell-bearing gravels and clays made the question of 

 recent submergence of especial importance. The shells were now 

 generally admitted by field-observers, including Mr. Maxwell Close 

 himself, to have been removed from their original habitat. The 

 speaker claimed that the submergence occurred in late Pliocene 

 times, and may have been merely the continuation of that which 

 deposited the Lenham Beds in England. Thus many of the so-called 

 ' recent ' species in Glacial beds might easily be derived from Astian 

 or even earlier strata, on which the great mixing influences of the 

 Glacial Period had been exerted. 



Dr. Hicks mentioned the deposits containing shells at heights of 

 from 400 to 600 feet in the Vale of Clwyd, North Wales, which are 

 covered by a Boulder Clay with northern erratics. 



1 Quart. Journ. Geol. Soc. vol. xlvii. (1891) p. 428. 



