211 
Of the same age is a Gravel Deposit at Wormald Green, 
at tlie east side of the stream, which, in its false bedding and 
the roughened surfaces of the Limestone pebbles, exhibits 
clear traces of having been washed out of older beds and 
re-deposited. 
It is to a fact belonging to the second of these beds, the 
Brown Boulder Clay, that I wish to draw your particular 
attention. 
On its eastern side the Boulder Clay spreads widely over 
the vale of York, and is mixed with or overlaid by more recent 
deposits. But its western side is more or less sharply defined, 
and lies upon the eastern edge of a very singular valley, 
which intersects the direction of the ordinary river courses 
almost at right angles. 
In the Memoir of the Geological Survey of the district 
this peculiarity is noted. * "Another curious circumstance is 
that although the stream coming down from Haddockstones 
now flows eastwards by Markington and South Stainley into 
the Ure at Newby, this does not appear to have been its origi- 
nal course ; for at Dole Bank, and thence southwards to Ripley, 
there is a well marked gorge, which in some places is fully 
as wide and deep as that of the Nidd at Knaresborough, 
and considerably larger than that in which the present 
stream flows. This valley is now only drained by the 
diminutive stream of Cay ton Gill, which joins the I^idd 
below Ripley ; but it is evident that a much larger stream 
must have cut this streamless defile at Dole Bank, where it is 
interesting to observe the abrupt turn the Markington Beck 
makes to avoid this valley.'' 
This valley is continued to the north of Haddockstones, 
forming the Dean, out of which flows a little tributary to the 
Markington beck, and a very small stream runs out north- 
wards into the Skell. 
* P. 21, Memoir of Geological Survey, 93 N.W. 
