Formations rich in fossils of many kinds, and of thickness sufficient Formations rich in fossils of many kinds, and of thickness sufficient 1869 1872 |
In our archipelago, I believe that fossiliferous formations could be formed of sufficient thickness 1859 |
I believe that fossiliferous formations could be formed in the archipelago, of thickness sufficient 1860 |
As the common rule formations rich in fossils would be formed in the archipelago, of thickness sufficient 1861 |
Formations rich in fossils, and of thickness sufficient 1866 |
to last to an
age age 1860 1861 1866 1869 1872 | age, 1859 |
as distant in futurity as the secondary formations lie in the past,
would generally be formed in the archipelago only would generally be formed in the archipelago only 1866 1869 1872 |
only 1859 1860 1861 |
during periods of subsidence. These periods of subsidence would be separated from each other by
immense immense 1869 1872 | enormous 1859 1860 1861 1866 |
intervals intervals 1866 1869 1872 | intervals, 1859 1860 1861 |
of time, during of time, during 1866 1869 1872 |
during 1859 1860 1861 |
which the area would be either stationary or rising; whilst rising,
the the 1861 1866 1869 1872 | each 1859 1860 |
fossiliferous
formations formations 1861 1866 1869 1872 | formation 1859 1860 |
on the steeper shores would on the steeper shores would 1861 1866 1869 1872 |
would 1859 1860 |
be destroyed, almost as soon as accumulated, by the incessant coast-action, as we now see on the shores of South
America; even throughout the extensive and shallow seas within the archipelago sedimentary beds could hardly be accumulated of great thickness during the periods of elevation, or become capped and protected by subsequent deposits, so as to have a good chance of enduring to a very distant future. America; even throughout the extensive and shallow seas within the archipelago sedimentary beds could hardly be accumulated of great thickness during the periods of elevation, or become capped and protected by subsequent deposits, so as to have a good chance of enduring to a very distant future. 1869 |
America. 1859 1860 1872 |
America; even throughout the extensive and shallow seas within the archipelago sedimentary beds could not, during the periods of elevation, be accumulated of great thickness, or become capped and protected by subsequent deposits, so as to have a good chance of enduring to an extremely distant future. 1861 1866 |
↑1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | Even throughout the extensive and shallow seas within the archipelago, sedimentary beds could hardly be accumulated of great thickness during the periods of elevation, or become capped and protected by subsequent deposits, so as to have a good chance of enduring to a very distant future.
|
During the periods of
subsidence, subsidence, 1861 1866 1869 1872 | subsidence 1859 1860 |
there would probably be much extinction of life; during the periods of elevation, there would be much variation, but the geological record would then be
least least 1859 1860 1861 1866 1869 | less 1872 |
perfect. |
It may be doubted whether the duration of any one great period of subsidence over the whole or part of the archipelago, together with a contemporaneous accumulation of sediment, would
exceed
exceed
1859 1860 1866 1869 1872 | exceed 1861 |
the average duration of the same specific forms; and these contingencies are indispensable for the preservation of all the transitional gradations between any two or more species. If such gradations were not
all fully all fully 1861 1866 1869 1872 | fully 1859 1860 |
preserved, transitional varieties would merely appear as so many
new and distinct new and distinct 1869 |
distinct 1859 1860 1861 1866 |
new, though closely allied 1872 |
species. It
is is 1861 1866 1869 1872 | is, 1859 1860 |
also also 1861 1866 1869 1872 | also, 1859 1860 |
probable that each great period of subsidence would be interrupted by oscillations
|