484: OBLIQUE FOSSIL TREES— FOSSIL FORESTS. [Ch. XXIV. 



greater, and 2 feet in its lesser width. The bark was converted into 

 a thin coating of the purest and finest coal, forming a striking con- 

 trast in color with the white quartzose sandstone in which it lay. 

 The foregoing cut (fig. 538) represents a portion of this tree, about 

 15 feet long, which I saw exposed in 1830,. when all the strata had 

 been removed from one side. The beds which remained were so 

 unaltered and undisturbed at the point of junction, as clearly to 

 show that they had been tranquilly deposited round the tree, and 

 that the tree had not subsequently pierced through them while they 

 were yet in a soft state. They were composed chiefly of siliceous 

 sandstone, for the most part white; and divided into laminae so 

 thin, that from six to fourteen of them might be reckoned in the 

 thickness of an inch. Some of these thru layers were dark, and con- 

 tained coaly matter ; but the lowest of the intersected beds were cal- 

 careous. The tree could not have been hollow when imbedded, for 

 the interior still preserved the woody texture in a perfect state, the 

 petrifying matter being, for the most part, calcareous.* It is also 

 clear that the lapidifying matter was not introduced laterally from 

 the strata through which the fossil passes, as most of these were 

 not calcareous. It is well known that, in the Mississippi and other 

 great American rivers, where thousands of trees float annually down 

 the streams, some sink with their roots downwards, and become 

 fixed in the mud. Thus placed they have been compared to a 

 lance in rest ; and so often do they pierce through the bows of 

 vessels which run against them, that they render the navigation ex- 

 tremely dangerous. Mr. Hugh Miller mentions four other huge 

 trunks exposed in quarries near Edinburgh, which lay diagonally 

 across the strata at an angle of about 30°, with their lower or 

 heavier portions downwards, the roots of all, save one, rubbed off 

 by attrition. One of these was 60 and another. 70 feet in length, 

 and from 4 to 6 feet in diameter. 



The number of years for which the trunks of trees, when con- 

 stantly submerged, can resist decomposition, is very great ; as we 

 might suppose from the durability of wood, in artificial piles, perma- 

 nently covered by water. Hence these fossil snags may not imply a 

 rapid accumulation of beds of sand, although the channel of a river 

 or part of a lagoon is often filled up in a very few years. 



Nova Scotia. — One of the finest , examples in the world of a suc- 

 cession of fossil forests of the Carboniferous period, laid open to view 

 in a natural section, is that seen in the lofty cliffs called the South 

 Joggins, bordering the Chignecto Channel, a branch of the Bay of 

 Fundy, in Nova Scotia.f 



In the annexed section (fig. 539), which I examined in July, 1 842, 



* See figures of texture, Witham, Foss. Veget., pi. 3. 



f See LyelPs Travels in N. America, vol. ii. p. 179 ; and Dawson, Geol. Journ., 

 No. 37. 



