Comparison with 1859 |
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consecutive. But we know, for instance, from Sir R. Murchison's
great work on Russia, what wide gaps there are in that country between the superimposed formations; so it is in North America, and in many other parts of the world. The most skilful geologist, if his attention had been
exclusively confined exclusively confined 1859 1860 1861 | confined exclusively 1866 1869 1872 |
to these large territories, would never have suspected
that that 1859 1860 1861 | that, 1866 1869 1872 |
during the periods which were blank and barren in his own country, great piles of sediment, charged with new and peculiar forms of life, had elsewhere been accumulated. And
if if 1859 1860 1861 | if, 1866 1869 1872 |
in each separate territory, hardly any
idea can be formed of the length of time which has elapsed between the consecutive formations, we may infer that this could nowhere be ascertained. The frequent and great changes in the mineralogical composition of consecutive formations, generally implying great changes in the geography of the surrounding lands, whence the sediment
has been has been 1859 1860 1861 1866 1869 | was 1872 |
derived,
accords accords 1859 1860 1861 1866 1869 | accord 1872 |
with the belief of vast intervals of time having elapsed between each formation. |
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But we But we 1859 1860 1861 1866 1869 | We 1872 |
can, I think, see why the geological formations of each region are almost invariably intermittent; that is, have not followed each other in close sequence. Scarcely any fact struck me more when examining many hundred miles of the South American coasts, which have been upraised several hundred feet within the recent period, than the absence of any recent deposits sufficiently extensive to last for even a short geological period. Along the whole west coast, which is inhabited by a peculiar marine fauna, tertiary beds are so
scantily scantily 1859 | poorly 1860 1861 1866 1869 1872 |
developed, that no record of several successive
and peculiar marine faunas will probably be preserved to a distant age. A little reflection will explain
why why 1859 1860 1861 | why, 1866 1869 1872 |
along the rising coast of the western side of South America, no extensive formations with recent or tertiary remains can anywhere be found, though the supply of sediment must for ages have been great, from the enormous degradation of the coast-rocks and from muddy streams entering the sea. The explanation, no doubt, is, that the littoral and sub-littoral deposits are continually worn away, as soon as they are brought up by the slow and gradual rising of the land within the grinding action of the coast-waves. |
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We may, I think,
safely safely 1859 1860 1861 1866 | safely 1869 1872 |
conclude that sediment must be accumulated in extremely thick, solid, or extensive masses, in order to withstand the incessant action of the waves, when first upraised and during
subsequent subsequent 1859 1860 1861 1866 | successive 1869 1872 |
oscillations of
level. level. 1859 1860 1861 1866 |
level, as well as the subsequent subaerial degradation. 1869 1872 |
Such thick and extensive accumulations of sediment may be formed in two ways;
either, either, 1859 1860 | either 1861 1866 1869 1872 |
in profound depths of the sea, in which
case, case, 1859 1860 1861 1866 | case 1869 1872 |
judging from the researches of E. Forbes , we may conclude that judging from the researches of E. Forbes , we may conclude that 1859 1860 1861 |
judging from the rescarches of E. Forbes , we may conclude that 1866 |
OMIT 1869 1872 |
the bottom will
be be 1859 1860 1861 1866 | not be 1869 1872 |
inhabited by
extremely few animals, extremely few animals, 1859 1860 |
few animals, 1861 1866 |
so many and such varied forms of life, as the more shallow seas; 1869 1872 |
and the mass when upraised will give a most imperfect record of the forms of life which then existed; or, and the mass when upraised will give a most imperfect record of the forms of life which then existed; or, 1859 1860 |
but it will not be, as we at last know from the telegraphic soundings, barren of life; consequently the mass when up-raised will give a most imperfect record of the forms of life which existed during the period of deposition. Or, 1861 |
but it will not be, as we now know from telegraphic and other deep soundings, barren of life; consequently the mass when upraised will give a most imperfect record of the forms of life which existed during the period of deposition. Or, 1866 |
and the mass when upraised will give an imperfect record of the organisms which existed throughout the world during the period of its accumulation. Or, 1869 |
and the mass when upraised will give an imperfect record of the organisms which existed in the neighbourhood during the period of its accumulation. Or, 1872 |
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