Percy F. Kendall — Glacial Geology. 491 



between the gravel and tlie laminated sand where they abutted on 

 each other on the fault-plane was as sharp as if the beds had been 

 cut with a knife. In the case of the bed of fine gravel (£), the 

 fault showed very prominently as the gravel projected some inches 

 from the face of the cliff in a band about three inches wide (C) in 

 which the pebbles were arranged with their long axes nearly vertical 

 and parallel to the fault-plane, just like the fault-rock in more 

 coherent material. The faulting is no doubt confined to the drift, 

 and does not affect the bed rock, which is Permian sandstone. 



Its cause was not obvious, and it was raining so hard at the time 

 that I had no opportunity of making extended observations. The 

 Drift has adjusted itself to different conditions of space from that in 

 which it was laid down ; but the chief lesson to be learned is the 

 mode in wliich this adjustment usually takes place, i.e., by shearing, 

 even where the material is of so incoherent a nature as gravel 

 and sand. 



V. — Glacial Geology, Old and New. 



By Percy F. Kendall, F.G.S., 

 Lecturer on Geology at Yorkshire College, Leeds. 



THE recent contribution of Mr. Eeade to Glacial Geology (Geol. 

 Mag. July, 1892, p. 310, et seq.) is a challenge which I take 

 up in default of a worthier champion. 



The origin of the drift deposits of Lancashire is not a question 

 of sand-grains. Mr. Eeade's observations upon those objects are a 

 useful continuation of the work of the late John Arthur Phillips, 

 but their bearing upon the rival theories is admittedlj' very remote. 

 If the sand-grains are of directly marine origin (which is by no 

 means certain, for the author makes no mention of derivation from 

 the New Eed Sandstone) they are just what one would expect in 

 association with sea shells on either hypothesis. 



Instead of the discussion of such rather irrelevant topics, Mr. 

 Eeade should give us a clear exposition of his views regard- 

 ing 1. The sequence of events in Britain during Glacial times. 

 2. The limits of the submerged areas. 3. The sources of the 

 glaciers which gave origin to the icebergs carrying e.g. the Criffel 

 granite to Moel Tryfaen. 4. Mode of origin of Boulder-clay, 

 especially of the intensely hard Till utterly devoid of stratification 

 which is sometimes met with. 5. The mode of production of the 

 strige found so commonly on the rock-surfaces. 6. The mode of 

 origin of the " ground-moraine " which he has described. 7. The 

 distribution of life in his supposititious glacial sea. One or two of 

 these could perhaps be conveniently discussed in the pages of the 

 Geological Magazine, but to deal with the whole of them with 

 a detailed disquisition upon Gloppa, Moel Tryfaen, etc., would 

 require that the Editor, whose obliging spirit is so well known, 

 should lease his journal and editorial chair to the Glacialists for a 

 couple of years, and allow them to bring out as many double numbers 

 as they pleased. I would remind Mr. Eeade of the proverbial 

 disproportion between the time required respectively for questions 



