260 
HUGHES : INGLEBOROUGH. 
lime, with hardly enough clay and iron to furnish here and 
there a small layer of ferruginous earth at the bottom of a cave. 
That the Great Scar or Mountain Limestone of Ingleborough 
was laid down in clear water may be inferred from its purity, 
and that it was formed at some distance from the source of 
sediment seems probable from the rolled and rounded condi- 
tion of the quartz pebbles in its lowest beds, and the absence 
of other foreign material, except quite at the base, where it was 
swept off the surface into hollows when the sea first crept over 
it. Further west the limestone thickens, and on the north 
gets split up by beds of sandstone, as mentioned above, while 
on the south it is sharpl}^ cut off by the great Craven faults. 
Here we have a clearly defined area and a special develop- 
ment well worth careful study. We see that it was built up by 
the accumulation of the fragmental and comminuted remains 
of the hard calcareous parts ot organisms that swarmed over 
the sea bottom. It is more or less coarsely crystalline, and the 
appearance of crystalline structure in the rock is increased by 
the cleaved calcite of the encrinite stems and other bodies which 
go to make up the mass. There is distinct bedding through- 
out, but the beds differ much. Sometimes they are very thick, 
forming bluffs and scars ; while sometimes they are thin, ir- 
regularly lenticular, and lend themselves to more gently rounded 
outlines. When beds affected by these different qualities and 
structures are superimposed, many curious and beautiful features 
are produced. For instance, on Moughton and Norber, and 
less conspicuously in other outcrops of the Mountain Lime- 
stone round Ingleborough, we see massive beds undermined 
by the w^eathering out of softer strata below, and giving rise to 
caves and abris, just like those in which primaeval man dwelt, or 
which, when walled up in front, furnished a shelter for the EngUsh 
soldiers who, in the Middle Ages, occupied the valleys of the Dor- 
dogne,* or those which in later times provided " cliff dwellings " 
for the Indians of Arizona, j and everywhere these natural 
features were enlarged, adapted, or even artificially imitated. 
* A. Laganne, Annales d' Agriculture de Dordogne. Lyell, Antiquity 
of Man, 1873, p. 134, and Fig. 12, p. 136. 
t Proc. Camb. Ant. Soc, Vol. TIL, p. 23. 
