33% SHEPPARD : SHAP GRANITE, ETC., IN LINCOLNSHIRE. 



formed the beautiful crescentric mounds around York, which have 

 been so lucidly described by Mr. Kendall.* These mounds are 

 terminal moraines. 



The Boulder Clays of Yorkshire and Lincolnshire, therefore, not 

 only mark the area covered by the ice, but contain boulders which 

 help to indicate the direction the ice took.f 



The Norwegian ice-sheet, as might be expected, laid down 

 a moraine, and this, a line of gravel hills, extends from Flamborough 

 Head into Lincolnshire, crossing the Humber at Paull. During the 

 many oscillations of the ice front the moraine was over-ridden 

 perhaps on two or three occasions. 



In addition to the great moraine just mentioned there is a 

 smaller, though none the less interesting, one, a few miles to the 

 west of this large one. This moraine (for such it is) crossed the 

 Humber at North and South Ferriby, the Boulder Clay cliffs on 

 either side of that estuary being all that is left of a bank of glacier 

 debris that once existed right across the river, which would no doubt 

 at some time interfere with its drainage. It was in this moraine, at 

 a depth of eighteen feet, that the pebble of Shap Granite referred to 

 at the beginning of this paper was obtained. 



It should here be remarked that whilst ' boulder-searching ' during 

 the past summer I found a piece of chalk thoroughly embedded in 

 the chalky rubble on which the bank of boulder clay rests at South 

 Ferriby, which was beautifully ice-scratched, the striations thereon 

 indicating that the ice which made them came from a north-easterly 

 direction. 



The foregoing remarks may perhaps appear to be a rather round- 

 about way of explaining the transportation of the boulders in East 

 Yorkshire and Lincolnshire, but it must be borne in mind that were 

 it not for the fact that the Irish Sea was filled with ice to over- 

 flowing, thus causing the Lake District ice to find its way into 

 the North Sea, to be afterwards dragged down by the Norwegian 

 ice-sheet, we should not have had the pleasure of finding Shap 

 Granite in Lincolnshire ! 



The whole subject is so full of interest that one could say much 

 more, but I feel I have already trespassed too much on valuable 

 space. However, I have endeavoured to show that simply recording 



-*-* 



♦The Giaciation of Yorkshire. Proc. Yorks. GeoL Soc., 1893. See also 

 Mr. C. Fox Strangways' paper in Proceedings of same Society for 1895. 



t Mr. Fox Strangways' paper (just referred to) is accompanied by an excellent 

 map showing the drift -covered area of Yorkshire, and a similar map appears with 

 Mr. A. J. Jukes-Brownes paper in Quart. Journ. GeoL Soc. for May 18S5, p. **% 



indicatir the range of the Boulder Clays in the county of Lincoln. 



Natural^ 



