| → suffered the extremity of 1859 |
| always suffered the extremity of 1860 1861 1866 |
| invariably suffered extreme 1869 |
| suffered extreme 1872 |
|
| ↑ 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 |
|
|
a
condition. But the descriptions which we
possess of the Silurian deposits over immense territories in Russia and in North America, do not support the view, that the older a formation is, the more
has
→suffered the extremity of
denudation and metamorphism. |
|
| The case at present must remain inexplicable; and may be truly urged as a valid argument against the views here entertained. To show that it may hereafter receive some explanation, I will give the following hypothesis. From the nature of the organic
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
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
|
