82 STUDIES FOR STUDENTS 
of the river, and it approximates a parabolic curve, rising toward the head 
of the stream (98). 
Rice makes the following statement: 
The condition of balance between erosion and deposition [by rivers] has 
been called by Powell the condition of baselevel (140). 
Brigham writes as follows: 
A baselevel is a plane to which denudation must reduce a stably poised 
land mass, and below which denudation cannot take place. The plane is 
that of the ocean surface . . .. The great river first cuts its bed close to the 
sea level, and we say that a portion of the valley is reduced to baselevel. It 
lacks a little of it, but the difference is so small that we neglect it. Gradu- 
ally the valley widens, and the baseleveled strip extends up the stream 
toward the heart of the country (281). 
Cowles gives a definition of ‘‘baselevel”’ which taken liter- 
ally gives it the meaning of a process: 
Denudation of the uplands and deposition in the lowlands results in an 
ultimate planation known as the baselevel (178). 
The derivative use of baselevel as the name of a worn-down 
land surface does not seem to be so common now as it was some 
ten years ago. A few examples will here suffice. 
Keith made frequent use of ‘baselevel plain,” or simply 
‘“‘baselevel,”’ as the name fora surface that had been reduced to 
faint relief, even though now uplifted and more or less dissected. 
He discusses the ‘considerable variation in the altitude of dif- 
ferent parts of the baselevel”’ or old Tertiary land surface in the 
Catoctin region district of Virginia (373). He mentions “hill 
tops marking the dissected baselevel” of the Shenandoah valley 
(374). The term seems to be applied in at least one instance 
to a peneplain in saying: 
It needs but little study of this baselevel to discover considerable inequal- 
ities in its surface (369). 
d 
Diller made equally free use of ‘‘baselevel plain” and of 
‘‘baselevel”’ in his account of an ancient surface of erosion in 
northern California. He states that ‘‘the western edge of the 
baselevel, where it enters the mountains, has an altitude of 2,600 
feet,” and on a later page he suggests two ways in which the 
‘deformation of the baselevel may be studied” (406, 430). 
