THE PICTOU COAL FIELD — POOLE. 251 



passes fi'om the hio-b ground to the westward and separates tlie 

 .spur from the wide extent of Carboniferous Limestone that fills 

 the valley to the southward. Along the course of this fault 

 Stewart's brook has cut its way in the softer measures. The fault 

 continues westward along the southern base of Weaver's moun- 

 tain thence across the East river and apjDears to be of great 

 magnitude, possibly having much of the influence on the coal 

 field imputed b}^ the Surve}^ of 1869 to the great South fault. 

 Knolls of diorite project at several points on the north side of 

 this fault along Stewart's brook, while limestones are in contact 

 on the south side. A boss of diorite belonoino- to this series is 

 exposed on McLellan's brook underlj'ing Carboniferous Lime- 

 stone on the south flank of the range, and again at Mountville 

 rocks probably of the same age lock in an outlier of Carbonifer- 

 ous Limestone between Silurian hills. With these exceptions 

 this system is not known west of McLellan's brook. 



Dr. Honeyman'^' apparently classes all these rocks with the 

 Silurian, but his descriptions of neighbouring localities are so 

 general that without other assistance than his writings it is not 

 in all cases clear his references do include all the portions of older 

 rocks alone here referred to, — those immediately skirting the coal 

 field. 



SlLL^RL\N. 



Besides the fossiliferous beds exposed near Park's mills, which 

 are classed as Medina, there is the wide stretch of barren slates 

 ascending to the summit already" referred to as of this age, and 

 on the south side of the spur of Cambro-Silurian approaching 

 McLellan's brook occurs an outlier of these beds which were mis- 

 taken for carboniferous shales and prospected for coal thirty 

 years ago. But the largest exposures ai-e westward, on the 

 west bank of the brook. Soft, foliated slates holding fossils, 

 directly underlie Lower Carboniferous conglomerate,- and loose 

 fragments of grit beds are full of remains of trilobites, corals, 

 .shells and encrinites. Whether this formation is continuous in 



(1) Trans. N. S. Instit. pp. 67, 73 of 1870 ; pp. 105, 141 of 1S71 ; p. 459 of 1877 ; p. 73 of 1878. 



(2) Geol. Survey Report, 1886, pp. 33, 36, 48. Honeyman, Trans. N. S. Inst., Vol. HI, p. 64. 



