Editorial. 



In the American chapter of the third edition of Dr. Geikie's 

 Great Ice Age, formational names were proposed for three of 

 the better known till sheets of the glacial series. It was not 

 without some hesitation that this was done because it was not 

 wholly clear that the time was ripe for nomenclature, but the 

 helpfulness of specific names and the superiority of strati- 

 graphic terms over the time-phrases, period, epoch and episode, 

 of controverted application, seemed to overbalance the infelicities 

 that would arise from the immature state of investigation. It 

 was anticipated that further study would give occasion for addi- 

 tions and emendations. The ready and general acceptance of 

 the names seems to have justified their proposal ; indeed, other 

 workers in the glacial field have felt that the method might, 

 even at once, be extended to other divisions less well elaborated. 

 To the names Kansan, lowan and Wisconsin, which were sug- 

 gested for the three best known till sheets (Toronto being applied 

 to an interglacial fossiliferous deposit, and Aftonian being sub- 

 sequently added) Dr. George M. Dawson has proposed to add 

 the term Albertan to designate a series older than the Kansan, 

 and Mr. Upham has proposed the addition of Warren, Iroquois 

 and St. Lawrence to designate later till sheets. Previous to these 

 additions Dr. Geikie had proposed a full series of similar names 

 for the European glacial deposits. 



The studies of the past two years seem to show that within 

 the limits of the series covered by the three names first proposed, 

 there is, probably, need for some extension and revision. This 

 arises chiefly from the progress made by the geologists of the 

 Iowa Survey, Messrs. Calvin, Bain, Norton and Beyer, and by my 

 colleague, Mr. Leverett. It will be recalled that in eastern Iowa 



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