314 THE PICTOU COAL FIELD — POOLE. 



relation to the ag-e of the rocks of the Sutherland area over 

 Fraser Ogg's ijuarry has not been overlooked, especially since 

 the statement of the Survey in 1869, placing them as Devonian 

 has been questioned. On the accompanying map this portion of 

 the field is marked " undetermined," although on the outline 

 map of four inches to the mile shewn at the meeting of the 

 Institute it is coloured doubtful Permian. The reasons for 

 believing this possible are many : — Immediately north of this 

 ground the New Glasgow conglomerate is lost, nor has any 

 drift from it been found. The beds dip northward at a light 

 inclination. To the eastward they apparently terminate against 

 a north and south fault, hading eastward, that is assumed to 

 extend from the bottom of the basin, where it was cut, to the 

 swamp that bounds the conglomerate escarpment to the west. 

 On the south lie Coal Measures very much disturbed, and the 

 anticline that crosses the basin marks the line where the 

 series of westwardl}^ downthrows give place to eastwardly 

 downthrows, in the north and south faults. The grain, colour, 

 and fracture of the (juarry stone are unlike any known among 

 the Coal Measures, but they do resemble those of the lowest 

 members overlying the conglomerate. At both localities are dis- 

 tinctive beds that weather a dead white. Both contain nodules 

 of limestone wdiich on weathering out leave the rock resem- 

 bling discoloured and rejected Gruyere cheese. The nodules of 

 limestone vary up to masses three feet in length, and weather- 

 ing shows they are very arenaceous and their structure to be 

 concretionary. Should pebbles of the conglomerate or fragments 

 of the botryoidal limestone distinctive of the lowest beds of the 

 Permian ever be found along the quarry ridge the question would 

 then be set at rest. 



Potter s Brook Section : — Where Potter's brook joins the East' 

 river a fault with an eastwardly course divides McLellan's brook 

 section, continuous over that of the Albion Mines, from this sec- 

 tion under review. The extent of the dislocation, Potter's brook 

 fault, is probably not great at this point, but it sharply reverses 

 the dip repeating the series of grey shales associated with a 

 marked band of compact black shale which is thought to be the 



