32 STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 



German border some of which are comparable to the English Fenland. 

 In the majority of the cases cited, accumulation occurred on coastal 

 plains, but the great rivers of Alaska, Sumatra, Paraguay, Brazil and 

 other lands flow amid vast plains, which are peat covered in much of 

 their extent. 



The total area, within which peat has been accumulating since 

 the Quaternary began, probably exceeds that in which similar de- 

 posits accumulated during any prior period of similar duration. That 

 is not to say that contemporaneous deposits wxre at any time con- 

 tinuous throughout the area ; they were not and they are not, any 

 more than brown coal or stone coal was continuous throughout the 

 regions in which rocks of the respective ages are found. One must 

 always bear in mind that the great deposits of peat did not begin at 

 the same time throughout their present extent. It is altogether prob- 

 able for all, as it is certain for many, that originally they were small 

 separated patches, beginning in favorable localities and becoming 

 united by transgression. This process is not confined to low-lying 

 areas; Lorie^^ has proved its importance in the Hochmoors of Hol- 

 land. If conditions favoring growth were checked, the individual 

 deposits would remain isolated. 



Growing peat offers great resistance to erosion, as is well-known 

 to those who are familiar with conditions on streams which are 

 subject to violent floods. But where the accumulation is on a 

 permeable yielding material, it may be floated oft' after long con- 

 tinued flooding. A good illustration has been given by Carpenter,^'* 

 who, in describing a ride through the Panama canal, says that on 

 Gatun lake he found floating islands, tropical swamps lifted from 

 their foundations by the rising water, some of them several acres in 

 extent. Other notes by this author may be given here, though 



sol," Arch. Mus. Teylcr, II., Vol. III., 1890, pp. 424-437 ; I. C. Russell, " Sur- 

 face Geology of Alaska," Bull. Geol. Soc. Amcr., Vol. I., 1890, p. 129; C. 

 Lyell, " Antiquity of Man," 1871, pp. 2Z^, 337 ; W. T. Blanford, " A Manual 

 of the Geology of India," 1879, p. 400; S. B. J. Skertchly, "The Geology of 

 the Fenland," Mem. Geol. Surv. of Great Britain, 1877. 



IS J. Lorie, " Les hautes tourbieres au nord du Rhin," Arch. Mus. Teylcr, 

 II., Vol. IV., 1893, p. 169. 



1^ F. G. Carpenter, " Steaming through the Canal," Los Angeles Times, 

 January 10, 1914. 



