STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 451 



titles of macerated vegetable material. The density of vegetation in 

 a Carboniferous Waldmoor was not inferior to that of a tropical 

 jungle. Rain would have practically no erect on even loose plant 

 stuff, while the meandering streams would remove, little from their 

 banks. Every one knows that such streams have great plumes of 

 confervas swinging from the banks, undisturbed year after year. It 

 is difficult to conceive of crustal movements so abrupt as to cause 

 floods, so sudden and severe as to sweep debris over the plain, to 

 destroy the great Waldmoor and to leave no trace of the dense vege- 

 tation in the newly deposited rocks. It is equally difficult to under- 

 stand why crustal movements should increase the water-supply. 

 They would lead to rapid draining of the region but could not bring 

 about terrific floods unless the rainfall were increased many times. 

 In any event the floods would be mere floods, not devastating tor- 

 rents, unless the Waldmoor area itself were distorted, in which case 

 it would not be available for a new Waldmoor. 



In I903,'*'* Sterzel described a Sigillaria stump, seen in the roof 

 of the Zachkohenflotz. It was 1.25 meter high and tapered from 

 1. 1 5 at base to 0.50 meter at top. The base was completely plane 

 and the border was sharp. There is no trace of branching or of 

 Stigmaria, as there should be if the plant were in place of growth. 

 The stem evidently had been torn from its place by muddy water, 

 robbed of its basal branching and then deposited in the roof of the 

 coal seam. The softened base had become flattened under pressure. 

 He states that the limit between coal and roof is " haarscharf " and 

 that nowhere does the plant rise out of the coal into the roof. Ster- 

 zel's description shows that here is the familiar " Sargdeckel." The 

 region is disturbed, the contact between coal and roof is sharp, 

 neither is in its original relation to the other. The faulting explains 

 the smooth base of the stump. Such stumps are not rare in roofs 

 of the Zachflotz and Segen-Gottesflotz of Zwickau area. 



Sterzel,^^ in a later paper, described a petrified forest observed 

 in the Rothliegende of the Chemnitz region. The rich locality, near 



4* J. T. Sterzel, " Mitteilungen aus der Naturwiss.-Samlung der Stadt- 

 Chemnitz," Ber. Naitirzmss. Gesells. Chemnitz, t. XV., 1903, Separate. 



45 " Der versteinerte Wald," etc., the same, Band XVIII., 1913, Separate, 

 P- 52. 



