1873.] WARD LAKE-DISTIUCT GLACIATION. 423 



western side of the Ullswater Valley, draining north-eastward, 

 comes in at the sonth-east corner. All geologists admit the fact of 

 the glaciation of the district in question ; and many notices of the 

 same have heen published. It has been my privilege to collect 

 details upon the subject, an outline of which I have now the honour 

 of submitting to the Society *, 



II. Leading Questions suggested. 



The fact of the glaciation being granted, several questions at once 

 suggest themselves. 



1. Did the glaciating agent work from north to south? 



2. Did it come from within or without the district '? 



3. Was this agent floating ice, a system of local glaciers, or an 

 unbroken ice-cap ? 



There are two main sets of observations directly bearing upon 

 these questions : — (1) The direction of the ice-scratches ; (2) The 

 direction in which the boulders have been transported. 



It will presently be shown in detail that the direction of the 

 former has reference in a general way to the valleys in which the 

 groovings are found. And that of the latter, the transport of 

 boidders, can only be learnt by an accurate knowledge of the solid 

 geology of the district. A few words must therefore be said upon 

 this point. 



A line drawn from the upper end of Ennerdale Lake, through Honis- 

 ter Crag, along the east side of Derwent Water, and across the lower 

 end of St. John's Yale to Mell Fell, will divide the map (PI. XV.) 

 diagonally from S.W. to N.E. On the K.W. side of this line lie the 

 Skiddaw Slates, on the S.E. side the volcanic series of Borrowclale. 

 No two sets of rocks could be more utterly unlike each other. On the 

 one hand, old mud rocks, much contorted and cleaved, of a blue-black 

 colour and usually soft, though containing some harder sandy beds ; 

 on the other hand, alternations of ancient lava and ash beds, gently 

 rolling in large curves, in some cases cleaved, and for the most part 

 hard. In the north of the district, about Skiddaw, granite and 

 metamorphosed Skiddaw slate occur — rocks of considerable hard- 

 ness and distinctive appearance. 



If, then, the glaciating agent worked in the main from north to 

 south, we should expect to find boulders of Skiddaw Slate, Skiddaw 

 Granite, and the metamorphic rocks associated with it, upon the 

 area occupied by the volcanic series ; if from south to north gene- 

 rally, we ought to find boulders of tbe volcanic series upon the 

 Skiddaw-Slatc area. The fact is this. Over the district under con-r 

 sidcration, not one boulder of Skiddaw Slate, Skiddaw Granite, or 

 the associated mctamorpbic rocks, has been found upon the area 

 occupied by the volcanic scries ; while boulders of the volcanic rocks 

 occur in thousands over a large part of the Skiddaw-Slate area up 

 to certain heights. 



* All the minor details of the subject are necessarily reserved for publication 

 in a forthcoming Surrey Memoir. 



