HUGHES : INGLEBOROUGH. 
353 
their relation to the other rocks associated with them, and what 
are their equivalents elsewliere. 
If Sedgwick walked home from Kirkby Moor he crossed the 
whole of the Silurian, and if he walked from his home in Dent 
to Ingleborough, he crossed it again, only this time mostly 
covered by great masses of newer formations, and exposed only 
in the deep valleys which have been cut down through the Carbon- 
iferous rocks. The higher beds of the Silurian are not seen 
under Ingleborough (Fig. 1). but the lower part of the series is 
well represented, and we will now consider the place of the 
Ingleborough Silurian in respect of the pliases of sedimentation 
which have produced important differences in the character of 
the rocks before we proceed to correlate the beds in detail with 
those of other areas. 
The Conditions which Determined the Character of the 
Silurian Rocks of iNGLEBor.ouGH. 
If you look at the Geological Map of England, you v.dll see 
from the pattern that there have been great anticlinal and syn- 
clinal folds running east and west, that tliey were repeated in 
several successive periods, and lastly that there were movements 
of such a kind that the axes of these folds now slope to the east. 
The trough which holds the Culm Measures of Devon passes 
under the Hampshire Tertiary basin, and the anticlinal of the 
Bristol Channel is prolonged under the Wealden uplift, while 
the coal basins of South Wales disappear under the Secondary 
rocks, and these in turn under the London Tertiary basin which 
plunges east under the Xorth Sea. 
The great bend in the Secondary rocks of the Midlands and 
East Anglia indicates an uplift which must have affected Mid- 
Wales, and. as all the other movements of elevation and depression 
belonging to this system can be shown to have recurred, so we 
may assume the probability that this also was of various dates. 
The Silurian and Bala Beds under Ingleborough are thrown 
into folds approximately parallel to those to which I have just 
referred (Fig. 2), and we must therefore inquire whether these 
facts throw any light on the geology of the district in which 
we are now specially interested. 
