CHAPTER VI. 

 CLASSIFICATION OF THE GLACIAL SEDIMENTS OF MAINE. 



PRELIMII^ART REMARKS. 



NAMES. 



A complete classification of the glacial sediments will not be possible 

 till the facts of all the glaciated countries are correlated. The masses of 

 glacial gravel have everywhere received local names, the ones in most 

 common use by geologists being the Scotch name kame, the Irish esker, and 

 the Swedish osar. At first geologists employed these terms as promiscu- 

 ously as they are employed in popular usage. Later an attempt has been 

 made at a classification founded on genesis. In a recent letter Professor 

 Chamberlin has set forth his views on this subject as follows: 



When these gravel accumulations arranged themselves in transverse irregular 

 belts and represent marginal action, especially where associated with thrusting action 

 on the part of the ice, they should be distinguished from the longitudinal gravel 

 ridges which represent the internal drainage system of the ice and whose development 

 is quite largely dependent on a stagnant or slow-moving condition of the ice in its last 

 stages. 



With the first class is associated the name "kame," with the second the 

 name "osar." 



As between the terms "osar" and "esker," the first, as I understand it, 

 has right of priority. The finest known example of the longer gravel ridges 

 is found in Sweden, the next is that of Maine. According to published 

 descriptions the gravels of Maine are more like those of Sweden than of 

 Ireland. Certainly the grandest gravel system of all ought to receive 

 recognition in our nomenclature. I retain the term "osar" for the longitu- 

 dinal gravel system, and shall for the present employ the word "esker" as a 

 general term applicable to any mass or ridge of glacial gravel irrespective 

 of genetic classification. Thus, if a series of separated deposits be known 



