I9II.] STEVEXSOX— FORMATION OF COAL BEDS. 629 



" Evidentlj- this forest grew on one of those marshy lands constantly 

 inundated, for between the stumps is accumulated the loose felt-like peat 

 characteristic of such grounds and containing about as much mud as vege- 

 table matter. Such a marshy forest, with the stumps of the trees still stand- 

 ing erect on the peat, has been laid bare on both sides of the Igurapi Grande 

 by the encroachments of the ocean. That this is the work of the sea is 

 undeniable, for all the little depressions and indentations of the peat are 

 filled with sea sand and a ridge of tidal sand divides it from the forest still 

 standing bej'ond. X'or is this all. At Vigia, immediately opposite to Soure. 

 on the continental side of the Para river, just where it meets the sea, we 

 have the counterpart of this submerged forest. Another peat bog, with the 

 stumps of innumerable trees standing in it and encroached upon in the same 

 way by tidal sand, is exposed here also." 



Forests buried during the recent epoch are such famihar and 

 commonplace features that further reference to them is unnecessary. 



Forest beds of Quaternary age have been reported by observers 

 in many parts of the world. Reference has been made already to 

 the great forest bed of southwestern Indiana, buried under 60 to 

 120 feet of later glacial material. AIcGee^*^ has described a forest 

 bed, which divides the glacial deposits in northeastern Iowa. It 

 was much disturbed during a later advance of the ice. Accumula- 

 tions of logs, stems, grasses and peaty soils occur at many horizons 

 in both the upper and the lower till, but they are in largest volume 

 and least disturbed condition at the junction of the two drift sheets. 

 The distribution is related to that of the upper till. Where the 

 glaciation was most energetic, the deposit is absent ; where less ener- 

 getic, it is present but broken up badly ; toward the eastern part of 

 the area, the disturbance decreases and the deposit is found in normal 

 condition with everything in situ. There one finds the peaty soil 

 with stumps and roots all evidently in place. 



Quaternary forest beds are many in Europe. It suffices to quote 

 from J. Geikie,^^° who has described the condition in Great Britain. 



" The broad facts then are these : at a depth from the surface, varying 

 from 20 to 60 or 70 feet, occurs a layer of peaty matter enclosing and 

 covering forest trees, the stools of which are often rooted in an ancient 

 soil. Above this buried land surface appear lacustrine, or estuarine or, as 



^^ W J ]^IcGee, " The Pleistocene History of X'ortheastern Iowa," 

 Eleventh Ann. Rep. U. S. Geol. Survey, 1891, Pt. I., pp. 199-577. Citations 

 from pp. 486-496. 



"' J. Geikie, " The Great Ice Age," 3d Ed., p. 405. 



997 



