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, the pure milk-white quartz 
of which the vein consists being divided hy 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 brillianey of a mirror. These large veins are, however, 
less auriferous than those of smaller size. 
