which 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
existing existing 1859 1860 1861 1866 | now existing 1869 1872 |
continents of Europe and North America. ↑1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | This same view has since been maintained by Agassiz and others.
|
But we do not know what was the state of things in the intervals between the
successive successive 1859 1860 1861 | several successive 1866 1869 1872 |
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
again again 1859 | again 1860 1861 1866 1869 1872 |
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
not not 1859 1860 1861 1866 1869 | hardly 1872 |
one
oceanic oceanic 1859 1860 1861 |
truly oceanic island (with the exception of New Zealand, if this can be called a truly oceanic 1866 1869 1872 |
island island 1859 1860 1861 | island) 1866 1869 1872 |
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
existed existed 1859 1860 1861 1866 | existed, 1869 1872 |
there, there, 1859 1860 1861 1866 | there, 1869 1872 |
palæozoic and secondary formations would in all probability have been accumulated from sediment derived from their wear and tear; and
would would 1859 1860 1861 1866 | these would 1869 1872 |
have been at least partially upheaved by the oscillations of level, which
we may fairly conclude we may fairly conclude 1859 1860 1861 1866 |
OMIT 1869 1872 |
must have intervened during these enormously long periods. If then we may infer anything from these facts, we may infer
that that 1859 1860 1861 | that, 1866 1869 1872 |
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
earliest silurian earliest silurian 1859 1860 | earliest Silurian 1861 1866 1869 | Cambrian 1872 |
period. The
coloured coloured 1859 1860 1861 1866 1869 | colored 1872 |
map appended to my volume on Coral Reefs, led me to conclude that the great oceans are still mainly areas of subsidence, the great archipelagoes still areas of oscillations of level, and the continents areas of elevation. But
have have 1859 1860 1861 | have 1866 1869 1872 |
we
any right any right 1859 1860 1861 |
have no reason 1866 1869 1872 |
to assume that things have thus remained
from
eternity? eternity? 1859 |
the beginning of this world? 1860 1861 |
the beginning of the world. 1866 1869 |
the beginning of the world. Our continents seem to have been formed by a preponderance, during many oscillations of level, of the force of elevation; but may not the areas of preponderant movement have changed in the lapse of ages? 1872 |
Our continents seem to have been formed by a preponderance, during many oscillations of level, of the force of elevation; but may not the areas of preponderant movement have changed in the lapse of ages? At a period
immeasurably immeasurably 1859 1860 1861 1866 | long 1869 1872 |
antecedent to the
silurian silurian 1859 1860 | Silurian 1861 1866 1869 | Cambrian 1872 |
epoch, continents may have existed where oceans are now spread out; and clear and open oceans may have existed where our continents now stand. Nor should we be justified in assuming that if, for instance, the bed of the Pacific Ocean were now converted into a continent,
|