1908, 115 



THE SHELVBHARING DRIFTS OF CO. DUBLIN 



BY J. R. KII,ROR. 



Most readers ot the /risk Nahira/is^ are familiar with questions 

 relating to the origin of the drift deposits of the region around 

 Dublin. Interest in the subject was much enhanced by the 

 discovery of shells in these deposits, of northern species; and 

 the account which Scouler gave of his discover}^ in the early 

 part of last centurj^ introduced, as we may say, amid calms, 

 a theme destined to gather round it an unwonted amount of 

 interesting scientific debate. The apparentl}* obvious hypo- 

 thesis of submergence of the land became (to follow the 

 metaphor) overcast with perplexing elements in the seventies, 

 when the shell-bearing gravels were found at high levels on 

 the Dublin mountains ; and, a little later, perplexity was fol- 

 lowed by somewhat stormy controversies when such large 

 demands were made upon the generally accepted hypothesis. 

 The controversies have at length subsided, and we have 

 happily reached the post-cyclonic stage of debate, enjoying a 

 cleared atmosphere and a more detailed and extended per- 

 spective. 



As long ago as 1838 John Scouler^ gave lists of shells which 

 he had collected in the gravels of Howth and Bray Head. 

 Those from the former place are included in the more com- 

 prehensive list of A. Bell. 2 This list is given in the subjoined 

 table under Howth, the species reported by Scouler not men- 

 tioned by Bell being Ttirbo littoreus and Nerita littoralis. Those 

 which Scouler reported from Bray Head were Cyprina 

 isla7idica, Tiinitclla terebra and Dentalium. 



Shells from the drifts of other low level localities were sub- 

 sequently reported by J. R. Kinahan^ and others, in connection 

 with which, while the glacial origin of the containing deposits 

 was not questioned, the marine agency of transport was 

 naturally inferred. The publication of Rev. Maxwell Close's* 

 paper, " The Elevated Shell-bearing Gravels near Dublin " 



^ Joiirn. Geo/. Soc. Dublin, \o\.\., pp. 266-276. 

 * Report Brit. Assoc. 1S90, p. 411. 

 "^ /ottrn. Geol. Soc. Dublin ^ vol. viii., pp. 87-60. 

 ^ [ourn. Roy. Geol. Ireland, vol. iv., p. 36-40. 



