16 J. Clifton Ward — Denudation of the Ldke-district. 



in Pre-Permian times through marine action, and ever since has been 

 at a standstill as regards denudation, with the exception, perhaps, of 

 the formation of some paltry ravine or evident stream -course which 

 even marinists cannot get over; or be a sub-aerialist, and believe 

 that in Pre-Permian times the sea rough-hewed a block of country 

 which the atmosphere has ever since been carving into its now 

 complex and beautiful form. 



The difference between a marinist and a sub-aerialist seems to be 

 this : the former believes in the great power of the sea and in little 

 or no other power besides ; the latter in the great power of the sea 

 to rough-hew, and likewise in the great power of the atmosphere to 

 sculpture. 



To touch briefly upon one or two points of surface-geology. From, 

 what I have at present seen of the Lake-district I certainly should 

 not have come to the conclusion that the " steep escarpments generally 

 face the east, south-east, or north-east ;"^ and since the general dip of 

 the Green-slate Series is to the south-east, one would expect rather 

 the contrary to take place. That dip-slopes to the east or south- 

 east are not more frequent in this case is due, I think, to the almost 

 uniform hardness of these so-called Green-slate beds ; since, not un- 

 frequently, where a well stratified ash-bed is found amidst the lava 

 flows, it gives rise, on a small scale, to a well-marked dip -slope on 

 the east or south-east and a corresponding escarpment looking west 

 or north-west. 



Among other things, Mr. De Eance speaks of the disbelief of some 

 people in the much-excavating power of streams and rivers in the 

 Lake-district.^ Now it seems probable that the special pro\'ince of 

 the rivers is not so much to excavate — though that is often done to 

 a very considerable extent — as to scavenger, to bear away and roll 

 to ever lower and lower levels material detached by the action of 

 the weather from the hills on either side. And how anyone can 

 walk along a steep Cumberland mountain-side, with the loose stones 

 slipping from under his feet at every step, with overhanging crags, 

 with many masses already half slipping, and many more now lying 

 at the valley bottom, or lodged on some projecting ledge, — some dingy 

 and moss-grown, others but freshly fallen; or can even watch how 

 the sheep, along their narrow self-made paths, are constantly helping 

 to lower the loosened material, and yet shut his eyes to the mighty 

 but slow denudation now taking place, is a wonder. 



Of the filling up of lakes by stream and river-borne material 

 there seems to be abundant evidence. Keswick Lake and Bassen- 

 thwaite were almost certainly once connected — and even now 

 occasionally are so in floods — yet they are at present separated by 

 more than three square miles of alluvium. In a similar way 

 Buttermere and Crummock Water are separated. Thirlmere has 

 been filled up at its head for at least a mile. There is many an old 

 lake too, now represented solely by a rich alluvial tract. Such 

 deposits as these, it must be remembered, represent only a fraction 

 of the denudation that has taken place since the Glacial Period, 



' Mackintosh, Geoi, Mag., Vol. II. ' Geol, Mag., Nov. p. 493. 



