Observations on the Recent Olacial Drift of the Alps. 261 



moraine in a more significant sense than the preceding, in that it 

 was not simply accumulated at the foot of the glacier, but was 

 formed by its mechanical agency ; and in that it marks the ter- 

 mination of a given glacial advance. 



It would appear to te much in the interest of precision of 

 thought and expression to confine the phrase "terminal moraine" 

 to accumulations produced by a glacial advance, and to employ 

 some other term, as peripheral moraine, for ridge-like accumula- 

 tions due to halts in the retreat of the glacier ; while the term 

 "ground moraine" should include the widespread, sheet-like de- 

 posits of retreating glaciers. Our classification of morainic accu- 

 mulations would then stand : 



I. Superficial Moraines. 



(a) Due to local environment and passive glacial agency. 



(b) Characterized by angular material. 



1. Lateral moraines. 



2. Medial moraines, 



II. Basal Moraines. 



(a) Independent of loccd environment and due to active glacial 



agency. 



(b) Characterized by worn material. 



1. Ground moraines (sheet-like). 



2. Peripheral moraines. 

 8, Terminal moraines. 



Besides the glacial accumulations, we have constantly to deal 

 with the associated torrential and other aqueous deposits formed 

 by the abundant glacial waters, but these may usually be distin- 

 guished by structural characters. 



The following observations relate to individual features of drift 

 phenomena, and will be found more or less disconnected, and the 

 paragraphs are arranged without much reference to logical sequence 

 of thought: 



1. The Rhone glacier surpasses all others visited in its instruct- 

 iveness in relation to drift deposits. After a course of nearly 15 

 miles, it descends precipitously, like a gigantic frozen cascade, 

 into a valley of the Hhone, where it finds a broader area and 



