488 
PALEONTOLOGY OF ILLINOIS. 
9 
cr smaller quantity, extends from Athens southward, to the Ohio river, and in 
Virginia, as far up the Great Kenawha river as Charleston, or about one hun¬ 
dred miles in a direct line. There is no trace of any volcanic agency in that 
country. No distubance of any kind is observable in the strata, which have 
their normal, slightly-marked dip to the eastward j nor does the sandstone it¬ 
self indicate, in its appearance, by a variation of its compounds or of its density, 
any trace of metamorphism. At Gallipolis, near the mouth of the Great Ken¬ 
awha, a number of fossilized trunks, still buried in the sandstone, are seen 
protruding from the bank, in which they have been petrified in a prostrate 
position. As these trees have been examined already by other geologists, and 
mentioned as indicating a peculiar direction of a current, by which they have 
been brought and deposited, a short account of them here may not be uninter¬ 
esting. There are five of them, from four to fifteen inches in diameter, their 
length unknown, lying, two in a southeastern direction, one due east, and the 
two others due south. The part seen out of the sandstone is much decayed, 
the outer surface, where it is preserved, is covered by a coat of coal varying in 
thickness from one-half to one-fourth of an inch. What is most remarkable, 
and bears directly on the question of their petrification, is that they appear to 
have been transformed into stone by different substances, showing a different 
kind of mineralization. In one of these trees the internal texture has been 
destroyed, and the woody tissue is replaced by a hard calcareous sandstone or 
clay, separating in layers of about one-fourth of an inch in thickness. A second 
is a compound of small crystals of iron flint, its interior being perforated 
lengthwise by a number of irregularly placed cylindrical apertures, filled with 
small iron crystals, forming regular stars of more than twenty rays. A third, 
of which I have obtained large pieces, it being of smaller size, four inches in 
diameter, is transformed into a compact, opaque, black silex, which does not 
preserve any trace of organic structure. (1) As these trees, of course, have 
been petrified where they are found now, it would appear as if different min¬ 
eral substances, held in solution in the water, had acted upon the woody tissue 
in different ways, according to its nature. In any case, it is evident that the 
petrification has been performed in various ways, by the slow action of the 
liquids penetrating the sand, and not by the uniform crystallization of silica as 
it is now produced in the hot springs of volcanic origin; This is more evi¬ 
dent, in considering silicified wood of our more recent formations. Neither in 
the plains of Kansas and Nebraska, nor in Eastern Arkansas, nor in Missis- 
(1) It is marked by inflated articulations, like a species of Anarthrocanna , Gopp., and 
is as yet the only specimen found in our Coal Measures which might be compared to the 
trunks seen by Prof. Brongniart in the coal mines of St. Etienne, France, and compared to 
Bamboos, from their inflated articulations. (Lyell. Manual, 4th ed., p. 319.) 
