I92I. No. II. THE STRANDFLAT AND ISOSTASY. I5 



developed solely by base-levelling of the subacrial denudation, without 

 the aid of marine denudation. 



A. is also wrong in assuming that the present strandfiat has been 

 formed mainly in preglacial time before the coast land had been dissected 

 bv the numerous fjords and channels now traversing the strandfiat. 



Profiles of the strandfiat and the high land behind it. like those given 

 in Chap. VII and \'III, and also the numerous profiles given in my report 

 of 1904 [PI. s XII — XX], demonstrate how very level the strandfiat may be 

 in some regions, and what sharply defined horizontal incision it may form 

 in the steep mountain side of the land. It is hardly conceivable that level 

 planes like these, can have been formed exclusively by a vertically working 

 process, like the subaërial denudation, ^^"e must assume that they have been 

 finally levelled by some process working horizontally. 



The writer has recently [1920, 1921, Chap. VIII] mentioned several 

 processes that may have a planing effect upon a land surface, even above 

 sea-level. But their levelling effect is small compared with that of marine 

 denudation in cold regions, where an active shore erosion is produced by 

 the disintegrating activity of the frost, in and just above the shore-line, 

 as will be described later. 



Let us, however, first examine more closely what importance the 

 various denuding processes may have for the denudation of the coast land 

 and for the development of the strandfiat. 



