The Origin of Fiords. 563 



hard rocky niountainous regions of Norway, and equivalent sea-lochs 

 are found in similar regions in Scotland ; broader rocky channels 

 occur in less elevated grounds in some parts of Devon and Cornwall ; 

 and water-filled valleys with still gentler slopes characterize the 

 coastal regions of Hampshire. 



No question, however, arises with regard to submergence in connexion 

 with these inlets. The problem is the origin of the main terrestrial 

 features, which may have been due to quite different causes ; hence 

 a grouping of the sea-inlets is desirable, more especially as the terms 

 gulf, bay, sound, loch, and firth, as the author points out, are loosely 

 applied to different features. He would class the sea-drowned valleys 

 into three main types : fiords, fiards, and rias. 



A fiord is described as " a long inlet which extends far inland 

 between steep opposing walls; it usually consists of long straight 

 reaches, which turn and receive their tributaries at sliarp and regular 

 angles; and its walls are high, as fiords are restricted to mountain 

 regions ". furthermore, there is " a rarity of bays and a scarcity of 

 sites for human settlements " as there is little or no margin between 

 wall and water, except small tracts at the head, or small deltas along 

 the sides of the fiords. They are characteristic of dissected plateaus, 

 and "streams flow gently across the uplands until they reach the 

 fiord-wall and then plunge down in picturesque waterfalls ". 



Eiards " usually have no large rivers draining into them ". They 

 "are due to a lowland area with an irregular surface of hard rocks, 

 having been partially submerged beneath the sea. The essential 

 difference between fiards and fiords is that fiards are characteristic 

 of coast-lands which rise but slightly above sea-level ". 



Rias are ordinary river estuaries, and the author adopts the Spanish 

 term, as such drowned valleys are well represented in North-Western 

 Spain. The rias and fiards are alike "in having curved lines, gentle 

 slopes, and indented shores ". It is admitted, however, that it is 

 difficult to establish sharp distinctions between fiords and other arms 

 of the sea; fiords pass gradually into fiards and rias, the changes 

 being due to modified conditions, such as increased submergence. 



It is pointed out that most fiords occur in the more northern and 

 southern areas of the globe, that they are in fact best developed in 

 regions that have been subjected to glacial action. Hence it is not 

 surprising that the excavation of the deep valleys has been attributed 

 to glacial action. 



The personal observations of Professor Gregory, fortified by a study 

 of the writings of those who have examined special areas in detail, 

 have led him to conclude that while "fiords are clearly valleys, of 

 which the lower ends have been drowned by the sea", nevertheless 

 " all the fiord-systems of the world owe their characteristic features 

 to earth-movements, and not to glacial action ". Moreover, "river- 

 action will not produce fiords." It must be borne in mind that the 

 deepest fiord, in Patagonia, is 4,250 feet, and that the Sogne fiord in 

 Norway descends to nearly 4,000 feet, with bordering walls 3,000 

 to 4,000 feet high. 



There is no doubt that many fiords were once occupied by ice, and 

 that much shattered and weathered rocky material was then cleared 



