If, with Elie de
Beaumont, we term the waters in which the Jura limestone and chalk formed a
soft deposit the 'Jurassic or oolitic', and the 'cretaceous seas', the
outlines of these formations will indicate, for the two corresponding
epochs, the boundaries between the already dried land and the ocean in which
these rocks were forming. An ingenious attempt has been made to craw maps
of this physical portion of primitive geography and we may consider such
diagrams as more correct than those of the wanderings of Io or the Homeric
geography, since the latter are merely graphic representations of mythical
images, while the former are based upon positive facts deduced from the
science of geology.
The results of the investigations made regarding the areal relations of the
solid portions of our planet are as follows: in the most ancient times,
during the silurian and devonian transition epochs, and in the secondary
formations, including the trias, the continental portions of the earth were
limited to insular groups covered with vegetation; these islands at a
subsequent period became united, giving rise to numerous lakes and
deeply-indented bays; and finally, when the chains of the Pyrenees,
Apennines, and Carpathian Mountains were elevated about the period of the
more ancient tertiary formations, large continents appeared, having almost
their present
p 287
size.
Pages:
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604