66 GILPIN ON NOVA 



appear that the vein matter has beeu derived from the measures encasing them. The 

 cross veins have not been the means of introducing the minerals, for they, as well as the 

 faults, are observed to shift and break veins already mineralised, and they seldom exert 

 any appreciable effect on their values. The former not uufrequently show the gold 

 caught in the breaks as smoothed out or " slickensided " plates. In a specimen from the 

 Albion Mine at Montagu, where a break had intersected a very rich portion of the vein, 

 the smoothed plate of gold had a superficies of several square inches, and a thickness of 

 about one quarter of an inch. The knowledge of these facts has in some districts pre- 

 vented the expense usually incurred when breaks of -the strata are met, for the inclination 

 of the pay ground being known, the barren portions of veins could be avoided. 



To the miner, the most interesting and important point about a vein is its " pay " 

 ground. When it is considered that the thickness of the worked veins averages from 

 three to ten inches, and that their values vary from one quarter of an ounce to five ounces 

 of gold to the ton, it is evident that he will make little profit unless his workings extend 

 into the richer zones, carrying over considerable spaces an approximation to the higher 

 values. I believe that in this province scarcely any veins have beeu tested even super- 

 ficially, unless they showed at their outcrop rust or some of the more common sulphides, 

 so accepted has become the axiom that otherwise there is no gold in them. 



The metallic compounds characterising the veins are sulphides and arsenides of 

 iron, galena, blende, copper pyrites, oxide of iron, copper glance, native copper, molyb- 

 denite, etc., found more or less disseminated throughout the vein, with small amounts 

 of gold. At certain points, following the lateral extension of a vein, are met zones where 

 these compounds are more abundant, and the gold is concentrated. As many as four of 

 these rich zones or " chimneys " have been observed on a nearly straight line forming 

 the axis of one or more veins. In a few instances, two distinct " pay streaks " or chimneys 

 have been met in the same vein. 



The zones occupy longitudinally in the veins a space varying from a few feet up to 

 several hundred feet. Transversely, the vein is not affected in width by their 

 presence, although sometimes the slate wall contains feeders and nodules of quartz rich 

 enough to crush. The zones sometimes pass abruptly into poor quartz, yielding from a 

 trace up to two pennyweights, or the percentage of gold gradually diminishes until 

 mining becomes profitless. It has been observed that when a zone "takes " in suddenly 

 on one side, it diminishes gradually in value as the workings approach the other side, 

 bvit this can hardly be given as the rule. The shape of these pay streaks is extremely 

 irregular ; they have, however, in all cases a decided dip, which is generally the same for 

 all those occurring in a given district. Thus they dip to the east at Oldham, Uniacke, 

 "Waverley, and Isaac's Harbor, and to the west at Montagu, Lawrencetown, and Eenfrew. 



The accompanying sketch ^ of the workings in a pay streak at Montagu will serve to 

 show the irregularity of their form and the general dip. Mining was discontinued at 

 the lowest portion when the quartz ceased to yield a profit, although the percentage of 

 gold was still decidedly greater than in the surrounding quartz. 



In the Albion Mine at Montagu, the vein was little mineralised, but whenever copper 



1 Sketch from paper on Nova Scotia Gold Fields, read before the North of England Institute of Mining 

 Engineers by the writer. 



