RELATIVE AGE OF THE GRANITES. 23 



once been continuous with the Corrie stratum, and that its 

 actual position is due to an upthrow by a protruding mass of 

 granite advancing from the central mass east of Goatfell. If 

 this be admitted, it would make the intrusion of the granite 

 posterior to the deposition of the carboniferous formations, 

 and so render probable an identity of age between the 

 Ploverfield granite and that of Goatfell and the nucleus. 

 We think, however, that this view is liable to question; we 

 often find exactly similar bands of limestone amid the strata 

 of coal sandstone, without any evidence of former continuity, 

 or such cause of disturbance; and the amount of vertical 

 displacement implied in the supposition could hardly have 

 taken place here without a fracture of the crust, and the 

 appearance of granite on the surface, so narrow is the band 

 of sedimentary strata superimposed upon the granite. A 

 positive conclusion, then, seems scarcely justifiable from this 

 case. A stronger presumption is derived from the high 

 angle generally assumed by the sandstones, where they 

 approach near the gi-anite, on account of the narrowness of 

 the slate band ; and from the degree of metamorphism which 

 in such situations they exhibit, a good example of which 

 occurs at the junction in the burn of the White Water, above 

 Corrie, where a gradual passage takes place from slate to 

 sandstone, clearly the effect of metamorphism, by the heat to 

 which both were subjected. The facts all tend to shew that 

 the granite was injected and elevated after the deposit of the 

 old conglomerate, and that the entire slate stratum on the 

 east or Corrie side was in a plastic state, under the influence 

 of the heat which fused the granite. 



Viewing all these facts in connection with the general con- 

 formability of the carboniferous strata to the old red sand- 

 stone, and the gradual transition from the one series to the 

 other, observed in several places, it is even probable that the 

 injection of the granite took place after the deposit of the 

 carboniferous formations; and that therefore the granites of 

 the three disconnected tracts may be all of one age, or belong 



