
CREA Ti Res Xi 
STRUCTURES RESULTING FROM DENUDATION 
Outliers and Inliers. Unconformity. Overlap. 
IN preceding chapters, frequent reference has been made ‘to 
denudation in explanation of certain constantly occurring 
phenomena. For example, it was necessary to point out 
that plutonic rocks are now visible at the surface simply 
because they have been bared or denuded by long-continued 
epigene action. The student who has followed so far must 
also have realised that the very existence of sedimentary 
rocks is evidence of denudation—for every bed of the kind 
has been derived from the breaking-up and disintegration of 
some pre-existing rock or rocks. Denudation and sedimenta- 
tion, in short, go hand in hand. We cannot have the one 
without the other. In the sequel, we shall discuss the subject 
of denudation, with special reference to the surface-features 
of the land; but, for the present, attention must be confined to 
certain rock-structures which may be said to owe their origin 
to denudation. 
Outliers and Inliers.—All land-surfaces are necessarily 
subject to degradation, and the marks of such degradation or 
wearing-away are necessarily most conspicuous in regions 
which have been longest exposed to epigene action. Vast 
masses of rock have been gradually removed from such 
regions, so that many formations which formerly extended 
continuously over wide areas have been greatly reduced. 
Sometimes, indeed, they are now represented by only a few 
interrupted sheets and isolated patches. Such is the origin 
of outliers. An Outlier, then, is simply a relic of some more 
or less ve bed, or series of beds, and may be shortly 
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