LOW PENEPLAINS 



133 



altitude of 

 1,000 feet to 

 500 feet or 

 less. The 

 relation of 

 this terrace 

 to the drain- 

 age suggests 

 that it is a 

 remnant of 

 a pre -glacial 

 valley floor, 

 and if so it 

 may be a 

 grade plain 

 contempora- 

 ry with the 

 low pene- 

 plains. 



These fea- 

 tures point to 

 a long con- 

 tinuance of 

 base-level at 

 approxi m- 

 ately its pres- 

 ent height, 

 the time be- 

 ing subse- 

 quent to the 

 uplift of the 

 older pene- 

 plain. It was 

 probably 

 during this 



