CioveUy^ North Devon. 497 



of original deposition on an unequal surface, or of subsequent 

 dislocation, appear to promise any plausible solution.* 



The average height of the cliffs, as far as we could judge by the 

 eye, is 130 or 140 feet; they are traversed in many places by steep 

 ravines running from north to south, and numerous outlying masses 

 of rock shew themselves above the sea at a small distance from low- 

 water mark, a character uniformly presented by the stratified rocks 

 along the whole of the Northern coast. 



In some parts the compact grauwacke was wanting for a consider- 

 able distance, in such cases the forms which the slate had assumed 

 were rather angular than curvilinear. In the sections of those which 

 have been called s.iddle-shaped strata, we observed usually that the 

 dip was more precipitous on the western side. In neither variety of 

 the rock could we discover any traces of organic remains, nor could 

 we perceive any imbedded fragments that should indicate their hav- 

 ing been formed from the debris of an earlier rock. The strata are 

 traversed by numerous veins of opaque white quartz, but no appear- 

 ances of any other mineral substances occurred. 



The Drawings annexed, (PI. SS and 34,) indifferently executed as 



* Professor Jameson (Syst. of Min. toI. 3.) lias ascribed these appearances to crystal- 

 lization. As wo are always accustomed to regard terms of science as retaining (where 

 the contrarj' is not expressly stated) the precise sense in whicli they have hitherto been 

 nniformly received, the use of this expression is perhaps not strictly correct. The cx- 

 tt'rnal ap[)carance of these rocks is certainly not tiiat of a mass of crystallized matter; 

 and that the phenomenon itself is not invariably connected with the p'rocess of crystal- 

 lization is evident from the consideration that those rocks which are the most highly 

 crystalline in their texture are the most free from (liLse singular configurations. That 

 these appearances, however, may have been effected by a process of Nuiure, somewhat 

 analogous to crystallization, and depending possibly upon the same r;'moter causes, is 

 perhaps the most satisfactory hypothesis that has hitherto been offered on the subject, 

 and such I apprehend to be the opinion of the school of VVern:?r, though somewhat ob- 

 scured by the adoption of a term implying identity of ojicration, in a case where the 

 utmost which can be fairly assumed to exist, appears to be a striking analogy. 



Vol. II. 3 R 



