From Eocene to Recent Time 255 



accumulate, and thus resulting in an increased supply and 

 yield." 



The last statement is Important, and as in nearly all 

 cases cited in previous chapters of this work, the heat 

 evolved in the stratigraphic disturbances, would amply ex- 

 plain the destructive changes undergone by the fish-oils set 

 free. 



The writer is compelled to add here that it seems to 

 him a matter for great regret, that while so voluminous 

 a literature has appeared bearing on the relation and pos- 

 sible economic value of the rock strata, there is a sad dearth 

 of information as to the organisms, the exact determination 

 of these, the precise beds in which they occur, and their 

 comparative abundance in these beds. Were such informa- 

 tion forthcoming It would undoubtedly greatly aid in de- 

 termination of the origin, the distribution, and the localiza- 

 tion of the oil supplies. 



Ill, Pliocene-Pleistocene Formation. The general 

 resemblance of this alike In physical and biological details, 

 to present-day conditions is such, that only a few features 

 need to be touched on here. 



Over at least wide areas of what is now land heavy 

 freshwater or eollan deposits took place. Thus during 

 Pliocene time the Norwich Crag and Cromer group In 

 England, the lower and upper Pliocene in Central France, 

 the Mainz beds of Germany, the Congerian and Thraclan 

 of Austria, the enormous Slwalik mass of north India, the 

 Marsupial beds of Australia, the Lafayette and pre-Lahon- 

 tan areas of North America, all reveal a land or freshwater 

 flora and fauna often of extreme richness and which ap- 

 proaches in general fades to existing conditions. 



