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the plain will be represented by a surface sloping in the same 
direction, and with the same inclination, as the original dip. If a 
synclinal is denuded, then the plain will be represented by a 
trough ; just as the denuded core of an anticlinal would represent 
a part of the old plain bent into a ridge; or as a quaquaversal dip 
would, when stripped of its newer rocks, leave behind a rock surface 
presenting the characters of a dome. These features are deter- 
mined, of course, by the movements of date posterior to that of 
the original plain, and are not in any way necessarily connected 
with the structure of the rocks out of whose edges the plain may 
be shaped. For example, an anticlinal in Cretaceous rocks may 
often coincide with a synclinal in the rocks below, or wice versa. 
In the original some further arguments were adduced in support 
of the view that the plain where Carlisle is now, extends without 
perceptible interruption in a south-easterly direction from the 
neighbourhood of that city, along the eastern margin of the low- 
lands of Edenside. Its characters are particularly-well displayed 
between Langanby and Melmerby, whence it extends for miles 
to the north west and south-east, with hardly any feature to disturb 
its uniformity. In this area, as around Carlisle, the Third Plain is 
shaped out of the ends of at least two thousand feet of New Red 
Rocks. By tracing the profile of almost any part of this plain— 
near Melmerby, for example—the fact becomes evident that the 
Third Plain, here, as elsewhere, gradually rises in the direction of 
the Lake District. Its slope prolonged just passes above the 
summit-levels of the Penrith Sandstone hills that range between 
Armathwaite and Penrith, which summits themselves appear to 
represent an undenuded strip of the old plain. Continued thence 
it rises a trifle above the present summits of any of the Carbon- 
iferous rocks (which are mainly calcareous) and extends thence to 
the level of the hill tops in the Lake District. The depressions 
that interrupt the continuity of the plain are exactly of such a 
nature as could be readily accounted for on the supposition that 
they are due to subaerial modifications of later date. In every 
_ case, except those manifestly due to river action, they are connected 
with the outcrop of some stratum more easily denuded than those 
adjoining, 
