ACCIDENTS IN RIVER DEVELOPMENT 



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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 drainage 

 and meandering rivers characteristic of a mature region. 

 The Palmyra, Virginia, sheet shows these characteristics. 

 The main rivers meander in steep valleys. A profile 

 shows these valleys to be steep and V-shaped with broad, 



INTRENCHED MEANDERS. 



rounded uplands between, well provided with drainage 

 channels. 



When the elevation extends beyond the mouth of 

 the river, the river must prolong its course over the 

 emerged land in order to reach the sea. It may happen 

 that rivers which formerly entered the sea at different 

 points, in extending their courses over the emerging con- 

 tinental shelf, join some large stream and all enter the sea 

 through it. 



This is what happened to the rivers now forming 



