ORIGINAL STRUCTURE OF THE URAL CONTINUED. 
465 
tiges, the record is usually defaced, though the walls are still standing, on which, 
according to the sequence in other countries, we ought to be able to decipher it. 
But let us not be misunderstood. Looking to the British Isles, we well know, 
that there are large tracts in them, where schistose deposits of considerable thick- 
ness, void of fossils, and also much associated with rocks of igneous origin, underlie 
strata in which Lower Silurian remains have been detected, and which yet preserve, 
like those of the Ural, a general parallelism to the fossiliferous rocks above them. 
We would not, therefore, dogmatically contend, that in the convulsed and crystal- 
line centre of the Ural, there may not have existed some such sedimentary masses 
which also were accumulated before the creation of the animals of the Lowei Si- 
lurian type. Recurring, however, to the facts, that all the sedimentary and meta- 
morphic masses of these mountains pi’eserve one to the other a perfect paiallelism 
of direction ; that the altered rocks are seen to graduate into the unaltered ; that 
the most altered occasionally envelope parallel bands ol limestone with oiganic 
remains ; and, lastly, that though a patch or two of true Lower Silurian strata are 
still recognizable, the regular place where, according to the established law of 
succession, such protozoic beds ought to appear, is commonly taken by rocks 
which have undergone metamorphism and mineralization, through the evolution 
of igneous matter along a great meridian fissure, we think we are fairly sustained, 
both by direct evidence and fair analogy, in maintaining, that the original deposits 
out of which, in conjunction with eruptive matter, the Ural Mountains have been 
formed, belonged chiefly to one great palseozoic sera, made up of the Silurian, 
Devonian and Carboniferous systems. 
From our own researches and those of others to the east of the chain, we are 
disposed to draw exactly the same conclusions in respect to the adjacent rocks of 
Siberia ; for although the characters of the last intrusive rocks are different, and 
though in some places granites (rocks very rarely seen in the Central Ural) usurp wide 
spaces in the lower ridges or Asiatic plateaux, we are unacquainted with a single 
phenomenon which can shake our belief, that all these granitoid rocks (whether at 
Verkhoturie, Ekaterinburg, Miask, or in the steppes of Troitsk) were emitted after 
the completion of the Carboniferous system, and for the most part were posterior 
to the greenstones and other eruptive rocks of the Ural. Trending parallel to 
the Ural chain, and therefore, in a broad sense, forming one of its appendages, 
these granitic, syenitic and associated rocks are essentially to be distinguished 
from the old crystalline rocks of Scandinavia, and must be viewed as of the same 
