See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1861
1866
1869

by atmospheric degradation and by the action of the sea during 1866 1869 1872
during 1861

a long period. 1866 1869 1872
an extremely long period,— a consideration which I formerly overlooked. 1861

also expresses his belief that 1866 1869 1872
in commenting on this subject, states that he believes the entire destruction of any 1861

rarely been completely destroyed. 1866 1869 1872
been of rare occurrence. 1861

these latter rocks 1869 1872
rocks of this nature must 1866

stript of their covering to 1872
denuded on 1866 1869

4 blocks not present in 1859 1860 1866 1869 1872; present in 1861
My remarks apply solely to beds rich in fossils: I have admitted that sediment accumulated in extremely thick, solid, or extensive masses would escape denudation. The point in question is, whether widely extended formations, rich in fossils, and of sufficient thickness to last for a long period, would be formed except during periods of subsidence? My impression is that this has rarely been the case. As the subject of complete denudation has been broached by Mr. Hopkins, I may remark that all geologists, excepting the few who believe that they see in the metamorphic schists and plutonic rocks the heated primordial nucleus of the globe, will probably admit that rocks of this nature must have been largely denuded.

whilst uncovered; 1866 1869 1872
in a naked condition; 1861

protecting mantle of rock 1869 1872
mantle 1861
protecting mantle 1866

OMIT 1869 1872
such rocks as 1861 1866

of this nature as 1866 1869 1872
as 1861

be much consolidated, nor
would it
....
be capped by
over- lying
overlying
formations, so that it would run a good chance of being worn away by atmospheric degradation and by the action of the sea during subsequent oscillations of level. It
has
has,
been
however, been
suggested by Mr. Hopkins, that if one part of the area, after rising and before being denuded, subsided, the deposit formed during the rising movement, though not thick, might
become
afterwards become
protected by fresh accumulations, and thus be preserved for a long period.
Mr.
Hopkins,
Hopkins
also expresses his belief that sedimentary
bed
beds
of considerable horizontal extent
to
....
have rarely been completely destroyed. But all geologists, excepting the few who believe that our present metamorphic schists and plutonic rocks once formed the primordial nucleus of the globe, will
probably
....
admit that these latter rocks have been stript of their covering to an enormous
scale.
extent.
For it is scarcely possible that
these
such
rocks
should
could
have been solidified and crystallized whilst uncovered; but if the metamorphic action occurred at profound depths of the ocean, the former protecting mantle of rock may not have been
thick.
very thick.
Admitting then that OMIT gneiss, mica-schist, granite, diorite,
&c,
&c.,
were once necessarily covered up, how can we account for the
extensive
naked
and
naked
extensive
areas of such rocks in many parts of the world, except on the belief that they have subsequently been completely denuded of all overlying strata? That such extensive areas do exist cannot be
doubted:
doubted;
the granitic region of Parime is described by Humboldt as being at least nineteen times as large as Switzerland. South of the
Amazon
Amazon,
Boué colours an area composed of
such
....
rocks of this nature as equal to that of Spain, France, Italy, part of Germany, and the British Islands, all conjoined. This region has not been carefully explored, but from the concurrent testimony of travellers, the granitic area
must be
is
very
large:
large;
thus, Von Eschwege gives a detailed section of these rocks, stretching from Rio de Janeiro for 260 geographical miles inland in a straight line; and I travelled for 150 miles in another
direction
direction,
and saw nothing but granitic rocks. Numerous specimens, collected along the whole coast from near Rio Janeiro to the mouth of the Plata, a distance of 1100 geographical miles, were
shown
examined by
me, and they all belonged to this class. Inland, along the whole northern bank of the Plata I saw, besides modern tertiary beds, only one small patch of slightly metamorphosed rock, which alone could have formed a part of the original capping of the granitic series. Turning to a well-known region, namely, to the United States and Canada, as shown in Professor H. D. Rogers's beautiful map, I have estimated the areas by cutting out and weighing the paper, and I find that the metamorphic (excluding
"the
"the
semi-metamorphic")
semi-metamorphic")