98 
the Red Rocks of the Eden Valley, and admitted of their upheaval 
to their present elevation ; therefore it is impossible that they can 
have ever extended farther in this direction at their present elevation 
than the plane, or upward continuation, of the fault. Now the 
very summit ridge of the Escarpment is frequently less than a mile 
back from. the fault; that is to say, the part that has been most 
cut back by denudation has receded only a mile. But the more 
prominent features of the Escarpment are at a much less distance 
than that, showing that the actual amount of denudation since the 
Escarpment first saw the light has been comparatively trifling. 
Subaerial conditions have affected similar rocks on the Continent 
and elsewhere to a much greater extent in post-Miocene times, 
and it therefore seems fair to conclude that, if less denudation has 
been accomplished here since a certain geological event, that event 
has in all probability taken place at a much more recent period. 
I would therefore approximately fix the date of the last upheavals 
here at the Miocene period, and would account for the compara- 
tively small amount of denudation the Escarpment and some other 
points have undergone since, by supposing that it is only in times 
much more recent that Edenside has been cleared of the Cretaceous 
rocks. Much of the denudation that every subaerial tract is 
inevitably exposed to having been expended in clearing out these 
newer deposits’; so that it is only at a comparatively recent period 
that the subaerial forces have been able to attack and to modify 
the features of a large part of the surface. 
Now, it was at some post-Miocene period, I believe, that the 
principal rivers of our district began to flow. I have endeavoured 
to show on a former occasion* that these rivers started into exist- 
ence at a time when the entire surface of the country was occupied 
with rock of one uniform character, and that the great water-shedding 
line of this part of England lay somewhere nearer this way than its 
present line along the Pennine range over there. Also that the 
rivers had their courses so well established in this rock of uniform 
character, that, when subaerial denudation had proceeded so far 
* Address at Nunnery Walks in 1880, published at the time in the Cardisle 
Patriot, &c. 
