a 
118 Mineralogy and Geology of the White Mountains. 
through the vein, but is confined to a portion of one side, three 
or four inches in thickness, and easily neparale from the mass 
of the vein. 
Trap Dikes cutting the White Mountains. 
At the foot of the gorge south of the Willey house, we find in 
abundance fragments of altered slate, slaty trap and basalt, and I 
am informed by a gentleman who passed over the mountain 
through this gorge, that in the upper part near the top, it is crossed 
by several trap dikes. Tmmense ruins lie at the foot of this and 
the gorge back of the Willey house, which appear as firm as the 
mountains, and are covered with grass, shrubs and trees, conceal- 
ing their deformity ; but those who have read the description in 
Vol. xv, of the wild devastation that reigned here, will at once 
penetrate the deceptive veil which vegetation throws over the 
whole scene. 
Dike in the Willey Gorge. 
From the melancholy associations of the last named gorge, my 
attention was more particularly attracted to it. The lower portion 
for a considerable distance is obstructed by the rocks and gravel 
that have rolled down from above. ‘There is a handsome vein 
on the north side, of crystallized feldspar, of a pale yellowish hue, 
with crystallized mica in granite. In the bed of the gorge, 
where it is but thinly covered by debris, beautiful flesh-red feld- 
Spar occurs, with many small cavities containing crystals of the 
same. Ruins of trap found here led me to ascend farther, and on 
passing the debris, a trap dike appears, forming part of the bed of - 
the channel. Its width is from two to six feet, usually averaging 
not more than four; course N. E. and 8. W., closely embraced 
by the red feldspathic granite, which is worn down to the same 
level with the trap. The dike is crossed about five hundred feet 
from the bottom, by a quartz vein or dike four feet wide, with 
parallel and vertical sides, at an angle of about 60°, the parts of 
which, on the opposite sides of the gorge, would be joined by 
right lines in the direction of its course, which indicates no dis- 
turbance or shifting. 
In the bed of the channel may be seen the trap, the quartz 
and the granite, all so interlaced, that it would seem impossible 
to decide whether the trap or quartz were the intersected vein ; 
or if they were not both contemporaneously injected, and that too 
