

Ch. XXIY.l ERECT POSITION OF FOSSIL TREES— SNAGS. 



Fisr. 53T. 



483 



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

 St. Etienne. (Ales. Brongniart.) 



now little doubt that M. Brongniart's view was correct. These plants 

 seem to have grown on a sandy soil, liable to be flooded from time to 

 time, 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 

 \vith their roots in situ appeared at many different heights.* 

 "When I visited, in 1843, the 



quarries of Treuil above men- 

 tioned, the fossil trees seen in 

 fig. 537 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 diameter at the top 

 was about 7 inches, and near the 

 base it measured 5 feet in its 



Fig. 538. 



Inclined position of a fossil tree, cutting through 

 horizontal beds of sandstone, Craigleith quarry, 

 Edinburgh. Angle of inclination from a to I 

 2V. 



Principles of Geology, 9th ed., p. 268. 



