OF DYNAMICAL GEOLOGY BAILEY. 191 



above, being of Devonian age, and in places filled with the 

 characteristic fossils of that formation. The best opportunities 

 for their study are to be found along the line of the Nova Scotia 

 Central R. R, between Alpina and Nictaux Stations, (this 

 interval being almost continuously occupied by rock cuttings, 

 usually fossiliferous,) the east branch of Bear River, (a mile and 

 a half above the head of the tide,) and in Mistake Settlement, 

 between North and South Range, in Digby County. The strata 

 include iron ores in addition to slates and sandstones, and the 

 former as well as the latter carry organic remains. Near the 

 granite the rocks assume more or less fully the character of 

 gneisses, while the iron ores, elsewhere hematites, have become, 

 in part at least, converted into magnetites. The fossils often 

 show also the distortions due to the pressure they have 

 undergone. 



VII. VEINS, CONTACT PHENOMENA, ETC. 



Space will not allow of any lengthy reference here to the 

 quartz veins of the Cambrian system. Nor is this necessary, as 

 their character and relations with the associated strata have been 

 so fully described by earlier writers in connection with the 

 development of the gold mines of which they form the basis. 

 It will be sufficient, in illustration of their occasional magnitude, 

 to refer to two instances only; the first, that of the "Jumbo 

 Mine," in Westfield, Queen's County, with a width, though not 

 wholly of pure quartz, of over sixty feet, while the second is that 

 on which was located the stamp mill, referred to above, at 

 Chegoggin Point, and which is about 26 paces across, of pure 

 milk-white quartz. At this latter locality may also be seen an 

 interesting example of slickensiding^he pure milk-white quartz 

 of which the vein consists being divided by a vertical fissure or 

 fault plane, of which one wall to an unknown depth has, by the 

 friction accompanying the fault, been polished to the smoothness 

 and brilliancy of a mirror. These large veins are, however, 

 1-ass auriferous than those of smaller size. 



