As the common rule formations rich in fossils would be formed in the archipelago, of thickness sufficient As the common rule formations rich in fossils would be formed in the archipelago, of thickness sufficient 1861 |
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 |
Formations rich in fossils, and of thickness sufficient 1866 |
Formations rich in fossils of many kinds, and of thickness sufficient 1869 1872 |
to last to an age,
as distant in futurity as the secondary formations lie in the past,
only only 1859 1860 1861 |
would generally be formed in the archipelago only 1866 1869 1872 |
during periods of subsidence. These periods of subsidence would be separated from each other by
enormous enormous 1859 1860 1861 1866 | immense 1869 1872 |
intervals, intervals, 1859 1860 1861 | intervals 1866 1869 1872 |
during during 1859 1860 1861 |
of time, during 1866 1869 1872 |
which the area would be either stationary or rising; whilst rising, each
fossiliferous formation
would
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 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. 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 |
America. 1859 1860 1872 |
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 |
↑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
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
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 1861 |
exceed
1859 1860 1866 1869 1872 |
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 fully
preserved, transitional varieties would merely appear as so many
distinct distinct 1859 1860 1861 1866 |
new and distinct 1869 |
new, though closely allied 1872 |
species. It is,
also,
probable that each great period of subsidence would be interrupted by oscillations
|