Mineralogy and Geology of Nova Scotia. 319 
basaltic walls. It seems here more properly a fine fragmentary 
rock, consisting of granular quartz and felspar, united with grains 
of serpentine of a dirty green color, and having a saponaceous 
feel. It is traversed by narrow seams of fibrous asbestus, a min- 
eral hitherto unobserved in this Province. But ina few places, be- 
coming finer grained and compact, it passes into the slate as at 
other localities. Although, in containing the serpentine, it differs 
from the quartz rock near Halifax (the effect of certain local 
and accidental causes), it possesses, in common with this, the 
general structure and composition of the quartz rock of Scotland, 
so ably illustrated by Dr. McCulloch, according to whom it 
is sometimes met with in the Highlands of Scotland in a frag- 
mentary form similar to this. It is not however, in this country, 
geologically associated with those rocks of the primary series, with 
which, according to that writer, it traverses different parts of 
Scotland ; but, as it is mineralogically the same rock as the Scot- 
tish aggregate, it is obvious that the same title should be applied 
to it, although, contrary to the systems, it fmay place this rock 
among the formations of a later epoch, to which, in fact, the re- 
cent discoveries of distinguished geologists have shown it to 
belong; as, according to M. De la Beche, it occurs with argilla- 
ceous slate, containing fossils, in France; and it is even de- 
scribed, by Humboldt, as a secondary rock in the Andes of 
Peru, where it is extensively interposed in a formation of alpine 
limestone with fossil shells.* Its’ occurrence, in Nova Scotia, in 
intimate connexion with slate, containing the remains of the 
trilobite, a crustaceous insect, hitherto found only in the oldest 
transition rocks, proves it a more recent formation, but allows us 
* Baron Humboldt’s Essay on the Superposition of Rocks in both Hemispheres, 
p. 296. 
