Tlie Peneplain. — Davis. 229 
by subserial agencies; but whatever the proportions, a well 
finished plain of denudation, hundreds of square miles in area, 
had taken the place of a vigorous mountain range, before the 
deposition of the limestones began. 
Goodchild has repeatedly referred to. this ancient plain of 
denudation, and to two others of later date in- northwest Eng- 
land. He says that when the deformed Cambrian and Silurian 
rocks "were brought within the destroying action of the waves 
.... the end of it was that the whole surface of the country 
was shorn ofif to one general uniform level; depressions and 
elevations there were, beyond a doubt, just as there are both 
depths and islands left on a modern plain of denudation; but in 
the main the surface was tolerably uniform" (Trans. Cumber- 
land and Westmoreland x\ssoc., xiii, 1888, 92, 93). Many 
mountain slopes in the Lake district consist of re-exposed 
areas of this ancient plain, from which the weaker cov- 
ering strata have been worn off again (Ibid., xiv, 1889, 76). 
The plain extends, locally, with marvellous evenness of con- 
tour, across the edges of quite five miles of strata" in the Lake 
district alone (Geol. Assoc, London. 1889, 45). 
B 4. Stratigraphic evidence is against the occurrence of 
peneplai/is. It is said that quiescence sufficient for peneplana- 
tion requires conditions different from "those of that portion 
of the past whose history has been worked out by purely 
stratigraphic methods" (p. 355). Although I am not sure of 
just what is meant by "purely stratigraphic methods." it 
seems fair to regard the two examples given in the preceding- 
section as dependent on at least a mixed stratigraphic argu- 
ment. These examples were, however, associated with marine 
strata, and hence the subgerial origin of the buried plains is not 
assured, although there can be little doubt as to the actual oc- 
currence of the plains themselves. The following examples 
are more pertinent to the present discussion, for they point 
chiefly to the action of subserial denudation in the production 
of peneplains. 
The Central plateau of France is a part of the ancient Her- 
cynian mountain system of post -Carboniferous deformation, 
that once stretched across west-central Europe. Judging by 
the strength of its foldings, its altitude may for a time have 
rivalled that of the Alps of to-day. The mountains were greatly 
