Yol. 70.] THE GLACIAL GEOLOGY OF EAST LANCASHIRE. 191) 



8. The Glacial Geology o/'East Lancashire. By Albert 

 Jowett, D.Sc, F.G.S. (Eead January 21st, 1914.) 



[Plates XXXI-XXXV.] 



Contents. 



Page 

 I. Introduction 199 



II. The Glacial Deposits 199 



(a) General Appearance and Texture. 



(b) Constituent Materials. 



(c) The Distribution of the Three Types of Drift. 



III. Evidences of Ice-action 208 



IV. Inferences respecting the Ice-Sheet and its Movements ... 209 

 V. Systems of Glacial Drainage 215 



(a) The Cliviger Series of Lakes and Overflow-channels. 

 (6) The Walsden Series, 

 (c) The Western Series. 



VI. Conclusions 225 



VII. Appendix : Instances of ' Terminal Curvature ' 227 



I. Introduction. 



The area dealt with in this paper comprises the western slopes of 

 the Pennines from Boulsworth Hill to Blackstone Edge, together 

 with the western offshoot from them, which separates the basin 

 of the Bibble from that of the Mersey. 



Although the treatment of the distribution of the Drift is 

 regarded as the primary object of the paper, I also intend to 

 examine the whole Glacial history of the district, in order that it 

 may be viewed in relation to the larger problem of the glaciation 

 of the Irish -Sea basin. 



A brief outline of some of my conclusions was presented to 

 the Southport meeting of the British Association in 1903. 



II. The Glacial Deposits. 



(a) General Appearance and Texture. 



The chief characteristic of the Glacial deposits — or, as they are 

 usually termed, the Drift — of this region is their variability. 

 Lenticular beds of sand and gravel alternate with clay, which 

 generally includes boulders of different sizes. Frequently, several 

 of these varieties of Drift occur together in the same section. By 

 far the greater number of exposures, especially in the uplands, are of 

 Boulder Clay, which consists of rounded, smoothed, and scratched 

 stones enclosed without orderly arrangement in a matrix of clay, 

 generally with an admixture of more or less sand. 



The texture of the Drift has had considerable influence upon the 

 Q. J. G. S. No. 278. p 



