WOODMAN: GOLD-BEARING SLATES OF NOVA SCOTIA. 383 
interior of the vein, and thus appears to have a common origin 
with the silica, and to have entered the fissures at the same period. 
There are very many veins filling crevices not coincident with 
stratification. These include, as one class, stringers connecting 
various bedded veins, and the “angulars” running off from them; 
but they belong to the age of the main leads, and need not be con¬ 
sidered here. In addition there are “ cross-leads,” as they are called 
locally, younger than the others and independent of them, and fill¬ 
ing irregular crevices or regular joints or fault-planes. In Nova 
Scotia they belong, in part, to a series running in planes of disloca¬ 
tion formed at the second period of folding and faulting, but 
erratically distributed, and not occupying all the faulted area. For 
the others it is impossible to find any system. Most of these and a 
large number of the former are barren ; but at Cow Bay a definite 
series occurs, carrying a fair amount of ore. 
The veins at that locality lie in nearly vertical fissures striking in 
general N. 25° W., and intersecting rocks which have the usual 
strike and an average dip of 40° S. The gangue is chiefly quartz, 
with some calcite. Pyrite and arsenopyrite are abundant, the latter 
massive. Galena and sphalerite are more common than in the 
bedded veins, and often are associated closely with gold, which is 
found free as well as in sulphides. The structure of the gangue is 
on the whole much more open and cellular than in stratified leads, 
and drusy cavities in the center of the mass are frequent, sometimes 
filled with galena and sphalerite. The quartz lies in part in distinct 
crystals perpendicular to the walls, in layers separated by films of 
impurities. However, in the larger veins the gangue is quite dense. 
The sulphides occur chiefly in the middle, and evidently were among 
the last minerals to form ; but their order and position are not con¬ 
stant. In a few cases, chalcopyrite was the last mineral to enter, 
and includes other sulphides. Arsenopyrite is scattered through 
the gangue, and occasionally projects from the whin contact into 
the quartz. It is abundant also in the whin. Pyrite is perhaps the 
commonest sulphide, and often is foifnd as a coating on horses. 
The galena is stated to carry silver. 
The veins are very persistent in strike and dip; but they send 
out innumerable small branches into the country-rock, and often 
two master-veins are connected through irregular cross-fissures 
which do not correspond to any definite structural feature of the 
sediments. The walls are far less definite than in the bedded 
