HUGHES : INGLEBOROUGH. 
133 
speculate upon their having originally formed part of the same 
plateau? And, if so, we have to admit that since the planing 
off of this great sea-plain all the land south of the Craven faults 
has dropped many hundred feet. Mr. Tiddeman is of opinion 
that this downthrow was going on in Carboniferous times. 
If we could prove that the Claughton Fell level belongs to the 
West Riding sea-plain, then we should have to admit that the 
downward movement on the south, whether by fault or by 
gradual southward slope, or by both, still went on long after 
the formation of the newest Carboniferous rocks. 
The Ingleborough sea-plain is newer than the great faults 
that run from the Eden Valley down Ravenstonedale to Lunes- 
dale, for the sea planed across the faults that throw the Car- 
boniferous rocks of Mallerstang and the rest of the Yorkshire 
moorlands on the east against the Silurian of the Howgill Fells 
on the west (see Fig. 1), leaving them both as parts of the 
Ingleborough sea-plain. 
If we could make a guess as to the approximate age of the 
Ingleborough sea-plain, to what age can we assign the much more 
ancient sea-plain of Snowdonia and Lakeland? It is a joy to lie 
on a clear day on the top of Ingleborough and think these 
questions out. 
If the origin of these sea-plains is such as I have described, 
they must be part of the most constant and continuous operations 
of Nature. They must be always in process of formation, and 
must always have been formed. AVe ought, thsrefore, to find 
traces of them in the rocks. 
Here on Ingleborough, from which we have the clearest view 
of two wide sea-plains which form part of the existing surface of 
the ground, we have also the most stupendous exhibition of a 
similar plain belonging to a far more remote Geologic past, and, 
as we were able to trace evidence of the newer plains far afield, 
and even to find in AVales representatives of both our higher and 
our lower sea-plain, so also we have satisfied ourselves by an 
examination of the crags round Ingleborough that there is a 
similar sea-plain buried under the mass of Carboniferous rocks of 
