142 
hughes: ingleborough. 
from side to side, alluvial flats were produced here and there, 
where there were in old times small tarns, and where after heavy 
rain flooded meadows may now be seen. 
The same conditions must once have prevailed in Chapel-le- 
dale. There, however, the rim of limestone has long ago been 
cut back, but the occurrence of beds of greater resisting power 
in the older rocks has kept up the barrier, and the water breaks 
from the first falls below Dale House, by many a rapid and 
cascade, to join the Greta at Ingle ton. 
On the other side of Ingleborough there is a small, narrow 
valley, now covered by the pretty artificial lake produced by 
constructing a high dam just above the village of Clapham. 
Further east we find the small valley of Crummack Beck 
(Plate XXIII. ), which is of the same type as Chapel-le-dale. 
This valley lies chiefly in Silurian and older rocks, but it is here 
much easier to see the reason for each interruption in the regularity 
of the features and for the barrier which arrested the cutting 
back of the stream at its lower end. Hard bands of grit, folded 
so as to present themselves to the denuding agent in the manner 
that made them least accessible to its action, are seen crossing 
the valley near White Stone Lane and barring the outfall east 
of Southwaite. 
One little tarn has been filled up with shell marl and peat, 
and as these are both useful, the one for dressing the land, the 
other for fuel, excavations have been made which reveal the 
Avhole story of their origin and infilling. 
Further east still is Ribblesdale, with its barrier at Swarth 
Moor and Great Stainforth, and rapids and waterfalls below. 
This valley has been cut down further through the nearly 
horizontal limestone rock. Part of it was certainly once occupied 
by a tarn, in which the trees and nuts brought down by storm, 
drifted chiefly to the south-west corner, where they are still to be 
found in the peat. Much of this valley is covered by gravel and 
alluvial mud, till we follow it up to the great mass of moraine 
matter about Horton which the river has not yet had time to 
remove or level. 
