258 



LYELL'S ELEMENTS OF GEOLOGY. 



Erect Position of Trees in the Coal Strata. 



speculation, but because it has furnished a popular argument to 

 some writers who desire to prove the earth's crust to be no more 

 than 5000 or 6000 years old. The fact did not escape the notice 

 of Werner, who conceived that the trees must have lived on the 

 spots where they are now found fossil ; and this hypothesis was 

 defended by M. Alexandre Brongniart, in the account given by 

 him, in 1821, of the coal-mine of Treuil, at St. Etienne. near 

 Lyons.* (Fig. 270.) In this mine, horizontal Coal strata aro 



Fig. 270. 



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

 St. Etienne. (Alex. Brongniart.) 



traversed by vertical trunks of Monocotyledonous vegetables re- 

 sembling bamboos, or large Equiseta. These beds are represent- 

 ed in the above figure (270.), and are from 10 to 13 feet in 

 height, consisting of micaceous sandstone, distinctly stratified, 

 and passing into the slaty structure. Since the consolidation of 

 the stone, there has been here and there a sliding movement, 

 which has broken the continuity of the stems, throwing the upper 

 parts of them on one side, so that they are often not continuous 

 with the lower. 



Now, had these trees, as some geologists contend, once formed 

 part of a submerged forest like that of Portland, before described, 



Annales des Mines, 1821. 



