348 L. D. CAIRNES EROSION AND EQUIPLANATION IN ALASKA 



Yukon and Alaska, is thus only a special phase of a general topographic 

 phenomenon. In all its phases, however, equiplanation is characteristic- 

 ally different from all other plain-producing processes — such as construc- 

 tional planation, peneplanation, glacial planation, etcetera — since in 

 these, materials are either added to or subtracted from the areas affected. 

 Equiplanation also differs fundamentally from peneplanation in that it 

 operates regardless of sealevel. 



