ADAMSON: SECTIONS EXPOSED IN SKIPTON AND ILKLEY RAILWAY. 367 
tortion, it may be stated that these beds dip respectively, beginning 
at the left or north side of the section, 60 degrees N.W., 52 degrees 
S E., 75 degrees N.W., 10 degTees S E. The rock thus bent is the 
mountain limestone, very similar in composition to the Skipton Rock 
already named. There are three great leading causes to account for 
this splendid example of contortion ; firstly, immense lateral pressure ; 
secondly, the slow and very gradual operation of the same; and 
thirdly, the pressure during crumpling of a vast thickness of over- 
lying strata, since removed by denudation. On the north side of the 
quarry was observed a good example of " slickensides ; " it was 
finely polished, and the groovings or stride were remarkably distinct. 
A little way from this section, a hurried glance was taken at the 
Wheelam Rock Quarry, where there is another fine example of 
contorted limestone beds. The limestime has a dip of 65 degrees 
S.S.E., but inside the quarry the beds tilt up again, and form a 
striking example of a synclinal or trough. The railway was again 
resumed, and an embankment traversed, about 1,000 yards in length, 
under which was found in foundations for bridges and culverts, hard 
black and brown shales. A short walk brought the party to a point 
where the line passes through the lower side of a quarry belonging 
to the Duke of Devonshire, and worked for limestone ; this is used 
for road metal, and also burnt for agricultural purposes. This 
quarry, known as the " Hambleton Rock," is famous for evidence of 
the great geological disturbance already referred to. On the eastern 
side of the quarry could be seen the various beds of shale and 
limestone (which were very distinctly laminated) dipping to the 
N.W., at an angle of about 40 degrees, then turning at a sharp 
angle and becoming vertical. The beds were seen to continue thus 
vertical to the west side of the quarry, and indeed, near the summit 
of the section in one spot, even to turn over a little upon themselves, 
thus actually reversing the order of deposition. The dark coloured 
limestone was traversed by innumerable veins of calcite, which were 
approximately transverse to the surface of the beds. An embank- 
ment was passed over about a quarter of a mile in length, on which 
will be situated the Bolton Bridge Station, distant from the Devon- 
shire Arms about three quarters of a mile. The Cutting No. 9 was 
