329 



has not yet been done to state adequately the relations of 

 the rocks of this complex series, but the Cobequid upland 

 is underlain predominantly by plutonic and volcanic masses 

 ranging in acidity from diabase to acid granites. The 

 originally intruded sedimentary roof is present now in the 

 central areas only as scattered remnants, but in the southern 

 belt of the upland there is a considerable development of 

 altered sediments, which are chiefly dark quartzites, black 

 slates, red and green argillites, green micaceous and 

 chloritic schists, and small areas of crystalline limestone. 

 At Wentworth station a small outcrop of fossiliferous slates 

 carries Silurian fossils, and Dawson on lithologlcal grounds 

 has assigned the remaining unfossiliferous quartzites and 

 slates to the Silurian with the exception of a few plant- 

 bearing beds doubtfully referred to the Devonian but 

 which are seemingly of Pennsylvannia age. 



Fletcher and Selwyn have regarded the entire Cobequid 

 series as altered Silurian and Devonian sediments cut by 

 post-Devonian intrusives. Ells, on the contrary, has 

 considered these rocks as predominantly Pre-Cambrian 

 in age, but with Cambro-Silurian sediments flanking the 

 range on the north, and with an isolated outcrop of Silurian 

 at Wentworth station. 



The Carboniferous rocks are not exclusively confined to 

 the Cumberland lowlands, as several outlying or inlying 

 conglomeratic remnants occur as isolated patches on the 

 Cobequid series. 



HISTORICAL NOTES. 



The Joggins section early attracted the attention of 

 geologists by the reported occurrences of many fossilized 

 trees still standing erect in the sandstone. In 1842 Sir 

 Charles Lyell made his first visit to this locality and was 

 impressed by the abundance of erect trees to be seen, as 

 stated in one of his letters: 



"Whither I went to see a forest of fossil coal-trees — the 

 most wonderful phenomenon perhaps that I have seen, so 

 upright do the trees stand, or so perpendicular to the strata 

 . . . .trees twenty- five feet high, and some have been seen of 

 forty feet, piercing the beds of sandstone and terminating 

 downwards in the same beds, usually coal. This subter- 

 ranean forest exceeds in extent and quality of timber, all 

 that have been discovered in Europe put together." 



