ACCIDENTS IN RIVER DEVELOPMENT 



187 



thus affecting its normal development and beginning a 

 new cycle in its history. The elevating may take place 

 over its whole drainage area or only over a part of it. It 

 may take place at any time during the history of the 

 river. If it takes place after the river has become old 

 and is meandering on its flood plain, the river will begin 

 afresh to cut down its valley. But as its meandering 



RIVER TERRACES, NORWAY 

 The river is now cutting down its former plains, leaving terraces. 



course has been established, the trench that it now 

 cuts is not like that of a young river, but is a meandering 

 trench, and what are called intrenched meanders are formed. 

 This region will have the steep V-shaped valleys charac- 

 teristic of a young region and the well-developed drain- 

 age and meandering rivers characteristic of a mature 

 region. 



It was the intrenched meandering valley of the Meuse 

 River at Verdun which furnished the upland spur forti- 



