TRANSACTIONS OP THE SECTIONS. 119 



by the wi'apping of hard and rigid strata round the central mass of Black Comb. 

 This formation alone would necessarily dislocate and fracture the beds of rock as 

 we now see them. 



It appears therefore that the phenomena observed in the metamorphic and 

 granitic rocks near Bootle may be accounted for without supposing the granitic 

 rocks to have been intrusive, or attributing the metamoi-phic action in the slate 

 rocks to the agency of the gi-anite. 



We may consider Eskdale and Miterdale, taken together, to be a broad synclinal 

 valley formed of the beds of the greenstone slate formation ; that the beds now 

 formmg the lower or central portion of that valley were the lowest beds of the series, 

 and were once covered up by a great thickness of the higher beds of this forma- 

 tion, such as now form Sea Fell and other neighbom-iug mountains, and were con- 

 sequently exposed to metamorphic action and converted into granite. The super- 

 incumbent strata being afterwards denuded, the granite beds appeared on the sm-- 

 face as wo now see them. On this explanation we must, of coiu'se, suppose the anti- 

 clinal ridge of Black Comb, as well as the sj'nclinal valley of Eskdale and Miterdale, 

 to have been formed before the metamoq^hic action took place, and that hence the 

 beds of rock in that ridge, and in tlie other boundaries of Eskdale above the level 

 of the granite, were not buried sufficiently deep below the former sm-face to be 

 strongly acted upon by the central heat. 



I may now perhaps ventm-e to ofter a few remarks and reasons in support of the 

 opinion that there exist no sufficient gi'oimds for separating gi-anites, syenites, and 

 other crystalline unstratified rocks generally, from the class of metamorphic rocks. 

 I by no 'means wish to assert that there may not exist in certain localities true 

 primeval granite — portions of the original and first-formed crust of the earth, or 

 that granite is not in innumerable instances an intrusive or eruptive rock jm a cer- 

 tain sense, and within certain limits. It may be impossible to prove the negative of 

 the first supposition ; the second is undoubtedly true. But I am not called upon to 

 dispute either of these suppositions — both are compatible with the opinion I am 

 supporting. For I think it is evident that we cannot suppose granite to exist in a 

 fluid state underneath solid strata full of cracks, fissures, and fractures, and not 

 perceive that, as a necessary consequence of its fiuidity merely, the granite must 

 penetrate and fill these cracks and fissures, and must have broken fragments or 

 masses imbedded in its substance. 



In this penetration of solid strata by fluid granite, the granite may be perfectly 

 passive. If true and constantly acting causes can be shown to exist, which must 

 throw the solid crust of the earth into flexm-es and contortions, and produce frac- 

 tures, cracks, and fissures, we have an explanation of the whole of the phenomena 

 without supposing the granite to be in any way an active agent. 



It may be objected that we see fluid lava forced up to high levels andpom-edout 

 from the sides of volcanos ; and why may not granite at former periods have been 

 subject to similar volcanic forces? Let us consider what are the necessary con- 

 ditions of a volcanic eruption of lava. One invariable condition is the presence and 

 violent liberation of vast volumes of highly compressed vapom's or gases, which 

 are evidently the active forces which drive up the lava and eject stones and ashes. 

 Volcanos are situated on deep fissures in the earth's crust, which admit air and 

 water occasionally to great depths, where, being enclosed by accumulations from 

 above and gradually and highly heated, their elastic tension at last is sufficient 

 to force up fluid lava with which they may be in contact, or to blow out the 

 obstructing materials which confine them in the shape of an ei-uption of stones and 

 ashes. 



But all these phenomena are local, and limited in extent ; the elastic vapours 

 cannot act explosively imless they are entu'ely enclosed within the walls of solid 

 strata, which afford the necessary resistance, and act indeed in the same manner as 

 the sides of a closed vessel woidd do. There is no evidence accordingly that vol- 

 canic vents pierce so deep as the seas of fluid granite which lie entirely rmder the 

 solid crust of the earth. And if elastic vapoui-s do exist in these subterranean oceans 

 of fluid rock, as no confining walls can there exist, their pressure will be distributed 

 equally in all directions and over large spaces, and there will be no tendency to 

 force up fluid rock in one place rather than another. There is then, I think, a clear 



