HONEYMAN GEOLOGY OF ANTIGONISH COUiNTY. 117 



Devonian strata been elevated, fractured and distorted ? and when 

 did this event happen ? We have no difficulty whatever in ascer- 

 taining the cause by which the effects referred to were produced, and 

 we seem to have no difficulty in determining that the event did not 

 happen until after such and such a period ; but the question of 

 time remains unanswered. About the geological base of the car- 

 boniferous system we find trap rocks, intervening between these 

 basal strata and the strata of a preceding age. These rocks appear 

 in enormous mass in contiguity with the lower carboniferous 

 conglomerates on the eastern side of South river lake, and they 

 extend backwards to Poison's lake, disturbing the Devonian strata 

 in that locality, as we have elsewhere observed. At McAra's 

 brook, at Arisaig, we have already observed their occurrence 

 between the Devonian and the lower carboniferous sandstones, 

 elevating the latter to the altitude of lofty mountains. As we 

 approach Malignant cove and near it, we observe on the road and 

 either side, trap in closest contact with lower carboniferous 

 conglomerate, the latter being metamorphosed into a hard jaspid- 

 eous rock by the original contact with its igneous associate. These 

 are seen in the same connection in Malignant brook, and crossing- 

 it in such a manner as to form the foundations of two mill seats, 

 and the opposite abutments of a bridge ; and in the same relation 

 extending westward to Doctor's brook, forming an elevated ridge 

 which runs between the older sedimentary or Silurian strata and 

 the metamorphic moiintains — {vide Geology of Arisaig.) In that 

 paper it was shewn that this trap also bounded the other side of 

 this silurian series from their eastern terminus, east of Doctor's 

 brook, extending along the shore, and much altering strata A, as far 

 as Arisaig pier, and being in the space intervening obscured by the 

 sea, it reappears at the shore at McAra's brook, and up the brook 

 as already indicated. From this it would appear that the upheaval 

 of the Arisaig silurian group took place at the period of this trappean 

 eruption, and that it was still in depths of the sea after the others of 

 the same oeolo"ical asre were subaerial. I know not how we can 

 otherwise account for the occurrence of the lower carboniferous 

 limestones and associated strata of the same age at Doctor's brook, 

 as indicated in my map and section, — (^vide Geology of Arisaig.) It 

 seems that this upheaval of sedimentary strata was at least post 

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