Ch. XXIV.] 



COAL — ERECT FOSSIL TREES. 

 Fig. 4G0. 



375 



Section showing the erect position of fossil trees in coal sandstone at 

 St Etienne. (Alex. Brongniart.) 



and raised by new accessions of sediment, as may happen in swamps 

 near the banks of a large river in its delta. Trees which delight in 

 marshy grounds are not injured by being buried several feet deep at 

 their base ; and other trees are continually rising up from new soils, 

 several feet above the level of the original foundation of the morass. 

 In the banks of the Mississippi, when the water has fallen, I have seen 

 sections of a similar deposit in which portions of the stumps of trees 

 with their roots in situ appeared at many different heights.* 



When I visited, in 1843, the quarries of Treuil above-mentioned, the 

 fossil trees seen in fig. 490 were removed, but I obtained proofs of other 

 forests of erect trees in the same coal-field. 



Snags. — In 1830, a slanting trunk was exposed in Craigleith quarry, 



near Edinburgh, the total length of 

 which exceeded 60 feet. Its diam- 

 eter at the top was about *7 inches, 

 and near the base it measured 5 

 feet in its greater, and 2 feet in its 

 lesser width. The bark was con- 

 verted into a thin coating of the 

 purest and finest coal, forming a 

 striking contrast in color with the 

 white quartzose sandstone in which 

 it lay. The annexed figure repre- 



Inclinedpositionofafossiltree,cuttingthrougu ' ,. r> ,i • , i 



horizontal beds of sandstone, Craigleith quar- sents a portion 01 tniS tree, about 

 ry, Edinburgh. Angle of inclination from a n ». /» , i i • i t j 



to & 27°. 1 o feet long, which 1 saw exposed 



=.»ll^« 



Fig. 491. 

















^S? 















- 





211l 





j 



- — j 







• ,- 



^^= 



















■■■i r - ; '<■■■". - 



' "^m 



* Principles of Geol. 9th ed. p. 268. 



