132 STEVEXSOX— FORMATIOX OF COAL BEDS. [April i8, 



vertical section must have been formed after the same general 

 fashion. Surprise is expressed because coal beds are believed by 

 any one to have an origin different from that of the sterile beds 

 enclosing them ; the presence of marine deposits in a column is evi- 

 dence that the whole column owes its origin to transported ma- 

 terials. But there seems to be little ground for any generalization 

 of this kind. It can hardly be accepted as accurate for a single bed, 

 though it has been so applied. Perhaps Fayol's statement is the 

 best illustration. He had proved that sandstone and shale are com- 

 posed of materials transported by running water and that the en- 

 closed fragments of plants had also been transported; shales and 

 sandstones, by increase of plant remains and decrease of inorganic 

 materials, become carbonaceous and, in some cases, pass into coal 

 beds ; community of origin throughout is clear. But there is a wide 

 gap here between premises and conclusion. The latter is possible, 

 even probable in some cases, but it cannot be accepted as a gen- 

 eralization, for the contrary is a familiar condition in actual peat 

 deposits, where one often finds all possible transitions from sand or 

 clay, on the border, through sandy or clayey peat to the clean peat 

 accumulating beyond. The general assertion, when applied to a 

 succession of deposits, seems to be equally inexact. Alternations 

 of peat with marine deposits are frequent on the coast of the Ger- 

 man ocean and English channel, and some of those peats are con- 

 tinuous with living bogs farther inland. Peat in the Bermudas 

 rests on marine limestone and underlies aeolian limestone. In the 

 same region, one may see a living coral reef, formed on submerged 

 aeolian limestone and now in process of burial under aeolian lime- 

 stone. A forest in Alaska still remains in situ, though a great thick- 

 ness of transported sands and gravels has accumulated around the 

 dead trunks. On many coasts, forests, submerged for centuries, are 

 still recognizable, though material from the land has almost buried 

 them. Borings in deltas and in river plains show that within a 

 vertical distance of 300 feet one may find land, freshwater and 

 marine deposits. 



Distribution of deposits by selective influence of gravitv is a verv 

 alluring suggestion, especially to those who believe that deposits 



