MINERALOGY OF FRANKLIN. 285 



has also been found, or to prove them to be of con- 

 temporaneous origin, as has been supposed by some 

 geologists ; but this hypothesis is in direct opposi- 

 tion to the fact, which we have previously mentioned 

 of its being found resting upon the edges of the lay- 

 ers of sienite ; this mistake may have originated from 

 observing the blue limestone on the south side of the 

 ridge, dipping to the south-east, and in apparently 

 parallel stratification with the sienite ; but there can 

 remain no doubt on the subject, when we connect this 

 limestone with that found upon the grauwacke half 

 a mile below ; we then find that their stratification is 

 quite independent of that of the sienite, but that it 

 depends upon the irregularities of the surface of the 

 sienite at the time of their formation, and that this 

 limestone covers the sienite in a real mantle formed 

 superposition. It has been said, that this limestone 

 contained impressions of organic remains, we have 

 searched for them with particular care, but have met 

 with none ; we think it not unlikely, that had there 

 been any in the rock, we could not well have missed 

 them, especially as our examination was particularly 

 directed towards the spot where we were told that 

 they had been found. 



It is, however, extremely probable that this lime- 

 stone was deposited with the remains of marine ani- 

 mals ; which were subsequently dissolved, as well as 

 that part of the rock which had received their im- 

 pression; this opinion is not entirely hypothetical, but 

 derives support from what appears to have been ir- 

 regular but small cavities, now occupied by calcspar 



