Professor J, W. Gregory — TJte English " Eskers'\ 25 



The English " Eskers " — their Structure and 

 Distribution. 



By J. W. Gregory, D.Sc, F.E.S. 



T^HE terms " kame " and " esker " have been applied in England 

 -*- to various mounds and ridges of sand and gravel. For some, 

 such as those in South-east Essex ^ either name is inappropriate, 

 since they are not glacial deposits but are tide-formed banks of 

 shelly sand. Most of the described English kames and eskers are 

 clearly related to glacial formations, and their distribution and 

 structure throw light on the later stages of British glaciation. 



The following terms are used in accordance with definitions 

 adopted in earlier papers ^ : (1) Drumlins, mounds of boulder clay ; 

 (2) Osar, fluvioglacial ridges deposited as receding river deltas and 

 typically with seasonal banding ; (3) kames, ridges or mounds of 

 sand or gravel deposited by water on the margins of an ice sheet ; 

 they include three varieties : {a) fluvioglacial ; (b) glacieluvial ; 

 (c) residual kames, those due to the denudation of thick banks of 

 glacial sand and gravel. Many residual ridges and mounds have 

 been described as kames, and some of them may be entitled to the 

 name as being due to an original thickening in a bed of gravel ; 

 but as it may be impossible to distinguish primary kames in an 

 advanced stage of denudation from the residues of beds of gravel 

 the application of the term kame to such cases is undesirable, 

 unless there is a strong probability of their formation as marginal 

 drift hills. 



The term esker has been applied to all varieties of Irish hills of 

 glacial sands and gravels, and has been used for English drifts in 

 a similarly comprehensive non-genetic sense. 



The following account of the English " eskers " is intended to 

 show which of them are osar and which are kames, and to consider 

 their distribution in reference to English glaciation. 



I. Northumberland. 



The kames of Northumberland may be divided into three groups. 

 The first group is in the N.W. part of the county near Coldstream, 

 and includes the kame at Wark Castle beside the Tweed and that 

 at Pallinsburn, N. of Flodden. 



1. Wark and Pallinshurn. — The best-marked kame on the English 

 bank of the Tweed is that at Wark. It has been described by 

 P. Mearns.^ 



1 Holmes, Geol. in Field, 1909, p. 57. 



'^ Geogr. Joiirn.. vol. xl, 1912, up. 169-75 : Trans. Geol. Soc. Glasgow, vol. xiv, 

 1912, pp. 199-218; Phil. Trans., ser. b, vol. ccx, 1920, pp. 115-51; Scott. 

 Geogr. Mar/., vol. xxxi, 1915, pp. 4G5-76. 



^^Hist. B'rrwick. Field Club, v, 1886, pp. 224-.31. Mem. Geol. Hurv., 

 no S.W., 1895, pp. 76, 77 ; Geol. Assoc, Geol. in Field, 1910, p. 695. 



