Mineralogy and Geology of apart of Nova Scotia. 137 
and lying confusedly in various directions ; the sands 
has cha oe to a dark red color, is more patie ipee 
become intimately blended with the shale, so that the e ye 
with difficulty distinguishes the substance peculiar to ar 
The sharp angular fragments of the trap are next observed, 
whole becomes a distinct breccia, growing more 
compact as it pe. Dene beneath the apap roc 
inion, 
combined with the trap, and produced amygdaloid by their 
ion. The numerous instances in which this occurred, as 
it did in fact at every junction of these rocks in Nova Scotia, 
and the absence of trap tuff and amygdaloid in places where 
this did not happen, or where, although the sandstone, &c. 
were not visible, it could fairly be inferred to exist beneath, 
led us irresistibly to this conclusion. That this process was 
attended by heat is inferred from numerous circumstances, a 
few of which can be mentioned here, and others in treating 
of the ack great divisions of the country which remain to be 
described. The occurrence of native copper in the trap tui 
and amnygdaloid, may be regarded as evidence in ot. 
this ; conversion of. claystone into fine red j asper, as 
entered the superincumbent trap ; the cylindrical cayities in 
the asopacelely at St. Croix Cove ; and even the existence 
vacant spheroidal cavities may be "considered as internal ev- 
idence in favor of this theory. The change of color in the 
sandstone from grey to red, and the compactness of the 
strata as it approached the trap; the absence of organic re- 
mains, and the charred state of the vegetable remains in the 
aciebbesing strata, give sufficient evidence, that, during 
the formation of the secondary trap in Nova Scotia, there 
was considerable heat. The sharp fragments of the breccia, 
and the breaking up of the strata, also shew, that the produc- 
tion of this rock, or rather its non-conformable position 2 
‘the sandstone strata was effected suddenly. Whether it w 
ejected from the inaccessible depths of the Basin of ed 
or was thrown directly up through the strata of sandstone, 
we cannot determine; but the occurrence of the trap only 
on the borders of the basin which it almost surrounds, would 
iced us to the belief that this cavity was the crater, if it may 
be so called, from which, in former times, the trap rocks issu- 
ed. The same rege will apply | to the whole North Moun- 
OL. 
