↑ 1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 |
This same view has since been maintained by Agassiz and others.
|
|
→ oceanic 1859 1860 1861 |
truly oceanic island (with the exception of New Zealand, if this can be called a truly oceanic 1866 1869 1872 |
|
→ we may fairly conclude 1859 1860 1861 1866 |
OMIT 1869 1872 |
|
do not appear to have inhabited profound depths, in the several formations of Europe and of the United States; and from the amount of sediment, miles in thickness, of which the formations are composed, we may infer that from first to last large islands or tracts of land, whence the sediment was derived, occurred in the neighbourhood of the
continents of Europe and North America. ↑
But we do not know what was the state of things in the intervals between the
formations; whether Europe and the United States during these intervals existed as dry land, or as a submarine surface near land, on which sediment was not deposited, or
as the bed of an open and unfathomable sea. |
|
Looking to the existing oceans, which are thrice as extensive as the land, we see them studded with many islands; but
one
→oceanic
is as yet known to afford even a remnant of any palæozoic or secondary formation. Hence we may perhaps infer, that during the palæozoic and secondary periods, neither continents nor continental islands existed where our oceans now extend; for had they
palæozoic and secondary formations would in all probability have been accumulated from sediment derived from their wear and tear; and
have been at least partially upheaved by the oscillations of level, which
→we may fairly conclude
must have intervened during these enormously long periods. If then we may infer anything from these facts, we may infer
where our oceans now extend, oceans have extended from the remotest period of which we have any record; and on the other hand, that where continents now exist, large tracts of land have existed, subjected no doubt to great oscillations of level, since the
period. The
map appended to my volume on Coral Reefs, led me to conclude that the great oceans are still mainly areas of
|