ORIGINAL ARTICLES. 



The English Eskers. 



By Professor P. F. Kendall, M.Sc, F.G.S. 



THE discussion by Prof essor Gregory in the February Geological 

 Magazine of ceitain ridges of glacial deposits in various 

 widely separated areas seems to call for some comment. I am 

 not familiar with all the examples classified by Professor Gregory 

 any more than he is, but a couple of examples visited by him, and 

 that I have examined many times, may serve as tests of his 

 trustworthiness as a field observer in Glacial Geology and his 

 competence as a commentator upon the observations of others. 



The first case is that of a remarkable drift ridge extending with 

 little interruption for a distance of about 3 miles along the high 

 Millstone Grit moorland overlooking the Wharfe Valley, from the 

 vicinity of Ilkley down nearly to Guiseley. Professor Gregory 

 selects for discussion an isolated segment known as Lanshaw, or 

 Laneshaw, Delves, a name, as I shall show, of extraordinary 

 significance to the geological investigator. Attention was drawn to 

 these ridges by Eussell,^ who describes it as " composed of limestone- 

 gravel ", which he amplified in the Geol. Surv. Mem. 92, S.E., to 

 " limestone-boulders mixed with pebbles and sand ". 



In the great memoir of the Yorkshire Coalfield the same author, 

 apparently, on p. 780, remarks : " These mounds have been dug 

 over for limestone, which they contain, so that their original form 

 is partly lost ; the limestone has been burnt on the spot, the ruins 

 of old limekilns occurring at intervals, and stones and chert which 

 have undergone the action of fire being scattered around." 



Carvill Lewis, whose account is commended by Professor Gregory 

 as the best (a judgment in which I do not concur), begins his descrip- 

 tion : " The eskers or sandbanks on top of the moor are known as 

 Laneshaw Delves, and limekilns have been built upon them." 



These descriptions are brief and give little detail, but a full 

 and detailed description of the ridges is given in a very important 

 paper unaccountably ignored by Professor Gregory. The authors, 

 Messrs. Jowett and Mufi (now Maufe),^ devote two pages of their 

 finely illustrated memoir to the description and interpretation of 

 the ridges, which they follow Carvill Lewis in recognizing as the 

 lateral moraine of a great Wharfedale Glacier. They remark that 

 " Along much of its course it has been dug into and turned over 

 for the limestone boulders which it contained ". 



It will be observed that every author cited mentions the occurrence 

 of limestone boulders in the ridge. And the two selected for citation 

 by Professor Gregory mention the lime-kilns. 



1 B.A. Report, 1873, Trans., p. 91. 



2 " The Glaciation of the Bradford and Keighley District " : Free. Tories; 

 Geol. and Polyt. See, vol. xt, 1904, pp. 193-247. 



