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University of California. 



|VOL. 2. 



should be noted here, however, that as a single peneplain may be, 

 and, indeed, is likely to be, of great extent, its remnants in a more 

 or less altered condition might give rise to descriptions of several 

 peneplains, all of which were, in reality, parts of the same original 

 form. 



From the fact that all so-called peneplains found to-day (not 

 buried) are elevated to a considerable altitude, none being found 

 even approximating sea-level ; and from the further fact that a more 

 or less even sky-line is a feature found in the majority of upland 

 regions which have been described of late years, we should be in- 

 clined to ascribe the " peneplained " or "beveled" character of such 

 regions, as Professor Tarr has done, to some cause inherent in the 

 processes of erosion under ordinary conditions, thus considering 

 the even sky-line a characteristic of mountain ranges in general. 



USE OF THE TERM BEVELING. 



The term "beveling," as proposed by Professor Tarr,* has not 

 been accurately defined, but it is apparently intended to cover all 

 the phenomena of those features of the present topography to 

 which the name of peneplains has been given, since the process is 

 offered as a substitute for that of peneplanation. That is, a beveled 

 surface is one in which there is an approximate uniformity of 

 crests, combined with a slight slope or tilting of the whole. This 

 is a direct application of the ordinary meaning of the word, since a 

 beveled surface is defined as a plane surface which makes with an- 

 other adjacent surface an angle which is not a right angle. Pro- 

 fessor Davis' interpretation of the term as the mere " truncation " of 

 individual peaks f seems, therefore, unnecessarily strained; and any 

 criticism of the proposed explanation based on this conception of 

 the meaning of the word, would fall to the ground, since truncation 

 is not beveling. 



According to Professor Tarr, an approximate uniformity of 

 mountain crests is obtained through erosion, and this uniformity 

 "would be greater near the sea, where development would have 



* Loc. cit, p. 366. 

 f Loc. cit., p. 235. 



