634 STEVENSON— FORMATION OF COAL BEDS. [November 3, 



Green/^^ visiting the locality some years afterward, remarked 

 that the conditions recall those in interglacial buried forests of 

 Great Britain ; for the " brashy " soil, containing the stools of large 

 trees, with here and there prostrate trunks, underlies a limestone 

 carrying estuarine fossils. Other " dirt beds " appear occasionally, 

 showing that the condition was repeated at some localities. 



Passing to the Palaeozoic, one finds many references to forests 

 and trees buried in place, for excavations and explorations are ex- 

 tensive and the localities, unlike most of those in the Mesozoic, are 

 in regions where scientific observers abound. 



Al. Brongniart^^* saw at the mine du Treuil, near Saint-Etienne, 

 a sandy bed, 10 to 13 feet thick, containing "a true fossil forest of 

 monocotyledonous vegetables, resembling bamboo, or a huge Eqiti- 

 setum, as it were, petrified in place." These are erect. There were 

 two types of stems; one cylindrical, jointed, striated parallel to their 

 edges and the cavity filled with rock like that which surrounds them. 

 The rarer forms are hollow cylindrical stems, diverging at the lower 

 end " after the manner of a root but without presenting any ramifi- 

 cation." Gruner'""^ notes the existence of another forest at the same 

 mine, but much lower in th.e section. The trees are Syriiigodcndron 

 and the roots rest on the coal. Brongniart refers to other localities, 

 where vertical stems had been seen, and he cites Charpentier, who 

 explained one rather notable case as due to landslides. Support for 

 this conception was found in the debacle of Lake Bagne, during 

 which great trees were carried down with the mass and deposited in 

 the original vertical condition position on the plain of Martigny. 

 But Brongniart maintained that such occurrences must be rare, 

 whereas vertical stems are found at many localities. At Treuil, as 

 well as near Saarbruck, one finds not merely a single large trunk 

 but many — a forest of slender stems, which have preserved parallel- 

 ism among themselves. It is perhaps more difficult to conceive that 

 sandy rock could envelop them after removal without destroying 



''^A. H. Green, "Geology," Fart L, London, 1882, pp. 252, 253. 



^"Alex. Brongniart, "On Fossil Vegetables Traversing the Beds of the 

 Coal Measures," Ann. des Mines, 1821. Trans, by H. de la Beche in "A 

 Collection of Geological Memoirs," 1836, pp. 210, 216. 



'" L. Gruner, " Bassin houiller de la Loire," 1882, p. 226. 



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