64 HONEYMAN GEOLOGY OF ANTIGOS1SHE COUNTY. 



Passing these soft strata we reach a ledge of trap, then a sinus 

 of the soft strata, and then another ledge of trap. A third exposure 

 of trap includes the mouth of McAra's Brook, section 11. Con- 

 tinuing the section we have unmistakable lower cai-boniferous con- 

 glomerate. This brings the junction of the pre-carboniferous and 

 lower carboniferous to McAra's Brook — the junction being con- 

 coaled by the trap of the McAra's Brook section. 



The continuation of the lower carboniferous conglomerate be- 

 comes interbedded with trap at intervals, which may be regarded 

 by some as contemporaneous, by others as intrusive. I regard 

 them as the latter, and consequently of a time subsequent to the 

 formation of the conglomerate. 



This alternation of hard igneous, and comparatively soft rocks 

 on a shore exposed to violent storms and wasting ice sheets, has 

 resutled in the formation of jutting ledges, precipices and caverns, 

 with trappean roofs. 



Running the section a short distance beyond the county line, we 

 have alternations of grits, sandstones and slates. A considerable 

 bed of Lower Carboniferous limestone, resting on slates, marls, 

 and a thin bed of oolitic limestone, with characteristic Lower Car- 

 boniferous fossils. 



Still farther we have sandstones with two thin beds of lignite 

 having grey sulphuret of copper. After these sandstones continue — 

 some of these have arenaceous concretions. 



We have now reached the end of our coast section. 



Ivxotdart Brook, Pictou Co. 



The sections described shew that we have in the Township of 

 Arisaig, three series of Pre-carboniferous Rocks : 



1. A crystalline series. 



2. A mixed crystalline and uncrystalline series. 



3. An uncrystalline scries. 



I have characterized the 1st as the Lower ; the 3rd as the 

 Upper, and I would now characterize the 2nd as the Middle series. 



