It is impossible here to enter into any discussion
as to the merits of the controversy to which this difficulty
has given origin. No one, however, can doubt the importance and
reality of the Devonian series as an independent system of rocks
to be intercalated in point of time between the Silurian and
the Carboniferous. The want of agreement, both lithologically
and palaeontologically, between the Devonian and the Old Red,
can be explained by supposing that these two formations, though
wholly or in great part _contemporaneous_, and therefore strict
equivalents, represent deposits in two different geographical
areas, laid down under different conditions. On this view, the
typical Devonian rocks of Europe, Britain, and North America are
the deep-sea deposits of the Devonian period, or, at any rate, are
genuine marine sediments formed far from land. On the other hand,
the "Old Red Sandstone" of Britain and the corresponding "Gaspe
Group" of Eastern Canada represent the shallow-water shore-deposits
of the same period. In fact, the former of these last-mentioned
deposits contains no fossils which can be asserted positively
to be _marine_ (unless the Eurypterids be considered so); and
it is even conceivable that it represents the sediments of an
inland sea. Accepting this explanation in the meanwhile, we may
very briefly consider the general succession of the deposits of
this period in Scotland, in Devonshire, and in North America.
Pages:
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222