CHArTEII TT. 



THK SUCCESSION OF DEl'OSlTS. 



ITiider this lieading I propose to luentioii, in a t,'eneml 

 maimer, the actual succession of deposits with wliich we 

 have to deal, and to consider what is known of tlie 

 probalde conditions of their accumulation and the geo- 

 graplucal and climatal features of the period. 



The deposits which we have to consider are superficial 

 or overlying beds of boulder clay or till, lannnated clay, 

 sand and gravel, widely distributed over the northern 

 part of the American continent, and accompanied with 

 lidges of detritus (kaims, eskers, etc.), and with travelled 

 stones and boulders or erratics. They may be arranged 

 as in the table on the following pnge, which refers to three 

 important and widely separated regions.* It will be 

 observed that in each of these there is a general corres- 

 pondence in the arrangement of the deposits, and that 

 these may be regarded as comprising a lower and upper 

 boulder formation separated by an intermediate bed or set 

 of beds evidencing a less amount of ice action. This 

 intermediate formation corresponds with that often named 

 " Inter-glacial" A similar order is observed in other 

 parts of America, and also in Western Europe. 



* Pleistocene Flora of Canada, Bui. Geol. Soc. of America, Vol. I. 



