THE PICTOU COAL FIELD— POOLE. 241 



Mill road fault :* — At Black's mill site, long abandoned, the 

 rocks on the high north bank of McLellan's brook are seen to 

 be disturbed. The throw of the fault Logan assumed to be 888 

 feet, but subsequent trial pits in 1878 at this point seemed to 

 prove it not over 15 feet or of little moment, and this finding 

 appeared continned ni 1889 by numerous exposures of the strata 

 along the immediate higliAvay which shewed a regular but rapid 

 turning over of the dip to the northeast. It is at this point that 

 the series of black shales, some 1740 feet in thickness, overlying 

 the Albion Main seam are succeeded by transition beds and then 

 by the sandstones alternating with shales that are noted in the 

 record of McLellan's brook — Section 8, page 19, and it seems pro- 

 bable that the observed dislocations at Black's mill site were 

 produced by the flexure passing from soft shales to I'ocks of a 

 harder texture. 



The change in the measures from black shales to heavy bedded 

 sandstones if it marked the location of a fault as assumed in the 

 report, would give it a course more to the westward of south 

 from Black's mill site than that shewn on the plan of 1869, but 

 this seems to have been overlooked at that time. A similar as- 

 sumption in 1850 lead to the abandonment of the Colin pits 

 which were started to forewin the main seam to the westward of 

 the Dalhousie pits, for in that sinking instead of black shales 

 only as in the shafts near the East river sandstones were pierced 

 and they had an inclination somewhat different from that of the 

 coal seam in the approaching workings ; hence a fault was 

 assumed to intervene. 



The possible extension of the fault northward is mentioned on 

 page 48, but the road exposures referred to above seem to dis- 

 prove it. In 1878, the Acadia Coal Co. put down a number of 

 boreholes along Shale brook, but they disclosed nothing that 

 w'ould tend to confirm the presence of this theoretical fault. 



Rolls : — If Logan considered a fault probable in this part of 

 the field to give relief to the strata turning from the middle to 

 the southern syncline, there is on McLellan's brook close above 



*Report 1869, p. 21, 40, 43 and 49. 



