388 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
opened for several years. On the summit of the hill 1,200 feet of 
the crest of the fold have been exposed by open quarries, but 
nearly half of this distance is now obscured. In addition, a tunnel 
runs 670 feet east along the axis from the lake-front, intersecting 
all the rock overlying the vein. From its end an up-raise is exca¬ 
vated along the vein, till the axis reaches nearly a normal horizon¬ 
tal position; and from the same point branch tunnels run north 
and south, following the strike of the vein in its change eastward,, 
giving completely the structure of the pitching fold. 
One of the points most noticeable in the openings, particularly 
in the quarries, is the flatness of the crown. This crown was the only 
portion exposed when the region was visited by Silliman and later 
studied by Hind, and gives a belt fifty feet wide in places, with 
almost no dip. This can be explained, however, by the fact — which 
a study of the whole field reveals — that it lies at the top of a 
folded series, and that it is immediately under a massive cap of 
whin. In contrast to this is the evenness of dip of the sides of the 
anticline. The vein in its descent soon reaches an angle which is 
almost constant throughout the vertical range observed, a total of 
230 feet directly and of nearly 1,200 by means of the fault-blocks 
and shafts to the west. This must mean either that some of the 
folds to which we give full swelling sides in section should be drawn 
with straighter shanks and narrow but flat crests, or that the fold 
in question is larger and deeper than anyone has hitherto thought.. 
If it be true that the deformation is more extensive than has been 
thought, it has a direct bearing upon the possibility of deep 
mining in the district—a plan which has been urged often by 
Canadian geologists, and as often rejected by conservative- 
investors. 
The tunnel shows that a thick cap of whin overlies the vein,, 
with but few thin bands of slate and one or two small veins. The 
surface outcrops on the hills, north and south of the axis, show 
nothing but whin for at least 500 yards. 
West of Fishing Lake is another area of whin, which, as far as 
my present study can determine, is a continuation of the cap over- 
lying the barrel quartz lead of East Waverly. It runs for an 
unknown distance westward, at least to the line of the Intercolonial 
railroad. Its attitude can be discovered only by occasional thin 
bands of slate; and by these it appears to form the end of a fold 
pitching west, like the other portions of the field. As it lacks eco- 
