ANNIVERSiLRY ADDRESS OF THE PRESIDENT. 137 



(h) Lake District. — (Arenig to close of Bala Period.) 



From the time of the appearance of Sedgwick's classic letters to 

 Wordsworth, no volcanic area of Britain has probably been so well 

 known in a general sense to the ordinary travelling public as the 

 district of the English Lakes. Many geologists have since then 

 visited the ground, and not a few of them have published additions 

 to our knowledge respecting what is now known as the Borrow- 

 dale Volcanic Series. The most elaborate and detailed account of 

 any part of it is that given by the late Mr. J. C. AVurd in the 

 Geological-Survey Memoir, wherein he embodied the results of his 

 minute investigation and mapping of the northern portion of the 

 district *. Notices of the petrography of some of the more interesting 

 rocks have subsequently been published by Mr. E-utley, Professor 

 Bonney, and others. But up to the present time no complete memoir 

 on the volcanic geology of the Lake District as a whole has appeared. 

 The sheets of the Geological-Survey map present a graphic view of 

 the general distribution of the rocks, but so rapid has the progress 

 of certain branches of geology been since these sheets were published, 

 that the map is even now susceptible of considerable improvement. 



In estimating the area over which the volcanic rocks of the Lake 

 District are spread, geologists are apt to consider only the tract 

 which lies to the south of Keswick and stretches southward to a line 

 drawn from the Duddon Sands to Shap. But it can easily be shown 

 that this area falls far short of the extent of that wherein the rocks 

 can still be traced, and yet further short of that over which the 

 lavas and ashes originally spread. For, in the first place, the vol- 

 canic group can be followed round the eastern end of the mountain- 

 group which culminates in Skiddaw, and along the northern base 

 of these heights to Cockermouth, though only a narrow fringe of 

 it emerges from underneath the Carboniferous series. It is thus 

 manifest that the volcanic rocks once stretched completely across 

 Skiddaw and its neighbours, and that they extend northwards below 

 the Whitehaven Coal-field. But, in the next place, far beyond these 

 limits, volcanic rocks, which there can be little doubt were originally 

 continuous with those of the Lakes, emerge from beneath the 

 base of the Cross-Fell escarpment, and still farther to the east a 

 prolongation of the same group rises for a brief space to the surface 



* Sheet 101 S.E. of the Geological Surv^ey of England and Wales and 

 Explanation illustrating the same ; also papers by him in Quart. Journ. Geol. 

 Soc. vols, xxxi., xxxii. (1875-76). See also Aveline and Hughes, Mem. Geol. 

 Survey, Sheet 98 N.E. (Kendal, Sedbergh, &c.). 



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