308 H. S. POOLE ON TRE GOLD-LEADS OE NOVA SCOTIA. 



While quartz veins are not confined to the districts where gold is 

 found in paying quantities, those that have been discovered to be 

 auriferous are generally about the axes of anticlinal folds, and pre- 

 sent an appearance which may be compared to a series of diversely 

 shaded sheets of paper sharply bent together, tilted at one end, and 

 cut horizontally. The lines of various shade which the sheets would 

 then show approximately represent the position of the leads and the 

 interbedding slates and quartzites. And, further, as that side would 

 be the more highly inclined on which the lateral pressure found 

 the least resistance, so do the strata incline at these anticlinals. In 

 the districts of Sherbrooke and Uniacke, for instance, the strata are 

 vertical on the south and incline to the north at an angle of 45°. 

 In other districts, as Waverley, Eenfrew, and Moose Eiver the ver- 

 tical and inclined dips are reversed. At Sherbrooke the leads on 

 both sides of the anticlinal are auriferous, and are only the width 

 of the main street apart ; while at Uniacke the north dip is two 

 miles away from the working-belt. On the top of Laidlaw's Hill, 

 in the district of Waverley, the lead lies so flat that it is worked 

 " longwall." In it the gold is chiefly found where it is crumpled 

 together by the folding of the strata and forms what are called 

 " barrels." These " barrels " or " rolls " have been followed down 

 on both the north and south dips. On the crest they run in the di- 

 rection of the axis of the anticlinal ; and on either side they trend 

 to the north and south, representing, as it were, the resultant of 

 the forces encountered in the upheaval. In the overlying stratum 

 the position of the plication in the quartz is marked merely by a 

 moderate undulation. The quartz having yielded in the greatest 

 degree to the lateral pressure would indicate that, at the time of the 

 upheaval, it was in a more plastic condition than the containing 

 rocks, and the more when it is observed that the rolls contain angular 

 fragments of slate, and send ofi'shoots and tongues of quartz up into 

 the superjacent stratum. 



The auriferous rocks are supposed to be contemporaneous with 

 those of the Cambrian ; but the horizon of the belts has yet to be de- 

 termined. It has been suggested by those who consider the leads to 

 be bedded deposits, that only the lowest rocks of the series contain 

 the gold-leads, which the anticlinal folds have brought to the sur- 

 face. But the lithological characters of the several districts point 

 to the existence rather of three groups in which auriferous leads 

 exist : — the lowest, composed of beds of slate and grits crumpled 

 and contorted and cleaving transversely to the laminae (in these 

 no paying lead has been found) ; the middle, of compact beds in 

 which quartzite predominates and the cleavage-planes generally 

 conform to the lines of deposition (strata of this group in the neigh- 

 bourhood of anticlinals are intercalated with numerous quartz-leads, 

 some of which only are auriferous to an appreciable extent). The 

 upper group, in the extreme western section of the province, consists 

 of olive-green fissile slates associated with beds of micaceous sand- 

 stone and at least one plumbagineous bed. Some of the strata are 

 highly chloritic ; in the true gold -districts chlorite is a rare mineral. 



