Yol. 62. ~\ ANNIVERSARY ADDRESS OF THE PRESIDENT. lxXV 



rhyolitic breccia — the Yew dale Breccia of Clifton Ward — stands 

 out prominently. 



The Buttermere Granophyre and some sills and dykes, chiefly 

 occurring in and around the central fells, are probably of Ordo- 

 vician age ; and the Eskdale Granite may be of that age, though 

 possibly newer. 



The Upper Slates. — The sedimentary formations grouped in 

 this division recall, in some respects, the Skiddaw Slates. It is 

 true that there is a greater variation in the lithological characters, 

 as indicated by such names as Coniston Limestone, Coniston Flags, 

 and Coniston Grits ; but, owing no doubt to subsequent change, 

 the contrast between the parts marked by flags and grits is not so 

 great as might be expected. As in the case of the Skiddaw Slates, 

 the country is marked by a general uniformity of outline. 



(b) The Movements at the End of Lower Palaeozoic Times 

 and their Effects upon the Rocks. 



As it is my object to show that many of the modifications 

 produced in the district, after the initiation of the drainage at a 

 much later period than that which we are now considering, owe 

 their character to the changes produced in the rocks in Old-Bed- 

 Sandstone times, it is necessary to pay close attention to the 

 nature of these changes. 



So far as the present lie of the older rocks of the area is 

 concerned, the existence of an anticlinal axis running in a general 

 east-north-easterly and west-south-westerly direction through the 

 Skiddaw Slates of the Skiddaw group of fells is a sufficient ex- 

 planation, for the Borrowdale Series of rocks dips away from the 

 Skiddaw Slates in a general northerly direction north of this fell- 

 group and in a southerly direction south of the group. So far 

 as the district is concerned, this axis is excentric ; and accordingly 

 the Borrowdale Series of rocks is soon succeeded unconformably by 

 the Carboniferous rocks on the north, while the latter rocks do not 

 appear on the south until we have traversed many miles of the 

 rocks of the Upper Slate-Group. 



But, although this general anticlinal structure explains the pre- 

 sent lie of the rocks, there are many complications which produce 

 a marked effect upon the physiography. It is therefore necessary 

 to give an outline of the views of Mr. Harker and myself on the 



/2 



