OF UNSTRATIFIED ROCKS AND VEINS. 151 



the strata reclining against it, as in the case of granite. 

 If we conceive that, by a still further process of waste, 

 not only the erupted trap, but the subjacent strata 

 themselves should have disappeared, we should arrive 

 at the fundamental mass, and find only the slender 

 remains of highly disturbed strata, covering this inter- 

 minable source of the erupted rocks. Trap would 

 then be to us as granite ; nor would any proofs of its 

 former eruption and overflowing remain. 



Now this is not a mere postulate. In the district 

 of Morven, a mountainous mass of trap, attaining to 

 1200 or 1500 feet in height, meets a similar mountain 

 of gneiss in a line not far deviating from the perpen- 

 dicular, its base being lost beneath the sea. Here the 

 gneiss reposes on, or meets the trap, precisely as it 

 would a mass of granite, and is in the same manner 

 disturbed at the junction. This trap mass is indeed 

 connected with a portion that covers secondary strata, 

 and which may be considered as its erupted part. But 

 this is fast wasting away; and the time, however 

 distant, must at length arrive, when the trap of Mor- 

 ven will present all the geological appearances of 

 granite, and when, should it accidentally have pos- 

 sessed the granitic mineral character of some of the 

 syenitic traps of Sky, it would be supposed an un- 

 erupted rock, and a granite. 



Similar appearances occur in Sky, where masses of 

 trap that, as far as we can discover, are interminable 

 downwards, pass through the secondary strata, which 

 are consequently found in the same relative position to 

 them that the primary strata sometimes are to granite. 

 One of these is many miles in diameter ; and, did 

 neither Sky nor any other district preserve the vestiges 

 of erupted and overflowing Trap, it might here also 



