272 GEOLOGY. 



not only their disposition and arrangement, but also their specific 

 and original structure. 



Skiddaw Slate. — The oldest of these slate-rock formations 

 is that called the Skiddaw Slate, which covers a tract of country 

 extending from the vicinity of Egremont, eastward to that of 

 Greystoke, and from Keswick northward to Isell and Bewaldeth. 

 It contains the Lakes Bassenthwaite, Crummock, and Lowes- 

 water, and forms the mountains of Saddleback and Skiddaw, and 

 that beautiful range which rises between the vales of the Der- 

 went and Cocker, including Grasmere, Whiteside, and Grisedale 

 Pike. The aspect of the country it forms, though not so rugged 

 as that of the next group of slate rock, sufficiently indicates that 

 this formation has been subjected to the action of some enormous 

 elevating and deranging powers, and, though of vast thickness, 

 the underlying granite has been forced through it in a state of 

 fusion, and appears at a spot to the eastward of Skiddaw, while 

 another igneous rock, the Syenite, has been pushed upwards in 

 such masses as to form the whole bulk of Carrock Fell and of 

 High Pike. This slate rock is darker in colour and less cleavable 

 than the more recent formations, and varies considerably in char- 

 acter and appearance in different situations, especially, as men- 

 tioned before, where it approaches the igneous rocks by which it 

 has been penetrated, when it is said to become metamorphic. 

 Besides the great main deposit, this rock is found at the south- 

 west corner of Cumberland, where it forms the mountain Black- 

 combe; and also in the neighbourhood of Shap. It has always 

 been held to be destitute of fossil remains, but we understand 

 these have been discovered in it, by Mr. Ruthven, of Kendal, to 

 whose practical knowledge of this branch of local science we are 

 indebted for a very valuable Geological Map of the District, to 

 which we gladly refer our readers. 



Gbeen Slate and Pobphyey. — Overlying this rock we have 

 the second, a still more extensive division of the great slaty for- 

 mations, called Green Slate and Porphyry, and forming, with the 

 exception of those mentioned, every mountain of importance in 

 the fell country. This vast group owes its formation to the action 



