REVIEWS 85 
the average is about three miles. A section of 35 miles across the 
gold measures gives eleven anticlines. These folds have been greatly 
flexed in a direction transverse to the closer folding, so that they form 
long domes. In the folding, the upper strata have slipped upward 
on the lower strata, these movements taking place largely along the 
soft slate layers between the hard quartzite layers. This has resulted 
in compression along the sides of the folds and the formation of open- 
ings along the crests. 
Gold-bearing quartz has been deposited in the Openings near the 
crests of the domes formed by the slipping of the layers. The veins 
thus deposited thin out rapidly along the limbs of the folds, but keep 
their size along the pitch for some distance, though finally pinching 
out. Where the folding has been close and the legs of the anticline 
form an angle of less than 45°, the large bodies of quartz on the anti- 
cline are called saddle reefs, the name given to such formations in 
Australia. 
As yet no general operations have been carried on to any depth 
through the arch core of the folds in Nova Scotia, although at various 
places a number of veins have been found. However, from analogy 
with the Australian gold-bearing veins occurring in a similar manner, 
it is believed that the quartz veins in Nova Scotia will be found to 
recur many times in depth. 
The laws governing the position and extent of the zones of quartz 
veins, as well as the laws governing the position and extent of the 
“pay streaks” within the veins, are given in detail. 
This work of Mr. Faribault’s will be of immediate practical advan- 
tage to mining men, some of whom have already testified to its 
accuracy and value. It is another instance, lately of frequent occur- 
rence, of geological work done from a purely scientific standpoint 
having direct economic value. 
From a scientific standpoint also, the results are of interest as 
illustrating a principle of ore deposition. In many districts, and par- 
ticularly in the Lake Superior District, it has long been known that 
ore deposits were partial concentrates in pitching troughs by decending 
waters. Van Hise has lately enunciated the principle that the openings 
in arches or pitching folds are favorable places for the concentration 
of ore deposits by upward moving waters. The formation of the gold- 
bearing veins of Nova Scotia seems likely to have occurred in this Way. 
Cakes: 
