376 
ELGEE : GLACIATION OF NORTH CLEVELAND. 
On the contrary, whatever extra-morainic valleys occur there, 
prove a flow towards the Guisborough Valley in another direction 
altogether. 
At the entrance to Kildale a low spur, called Castle Hill, 
projects from the slopes of Easby Moor at an extreme elevation 
of 600 feet (Plate LIII.). The drift here appears to fill up 
a small preglacial vallej' or depression, which exists between 
the main hill and now forms Sowerdale, and a small outlier of the 
Sandy Series of the Lias at Burrow Greens Wood, round the ver^^ 
base of which flows the River Leven. Across this spur, over- 
flows, both into and out of Kildale, have certainly taken place, 
a fact noted by the late Rev. J. Hawell,* who says, " I have 
recently discovered that there was almost certainly an over- 
flow from the Eskdale Lake at one time into Sowerdale. Any- 
one looking at Sowerdale will be able to see that the denudation 
of it cannot have been entirely due to tlie insignificant stream 
which now percolates through it." 
An examination of the ground showed some peculiar features. 
Sowerdale itself is about half a mile long and cuts right across 
the spur, and is divisable into two portions where the path from 
Copper Hall to High Farm on Castle Hill crosses it. Here 
is a trench at 575 feet, about 25 feet deep and quite stream- 
less. It falls to the south-east, where it opens on to the steep 
slopes above tlie Leven. In the lower portion a spring has 
produced a small runlet of water, but this has evidently not been 
the cause of the valley, which is clearly an overflow and 
seems to have drained the Gribdale Gate area (possibly with the 
addition of the overflow from the Boosbeck Valley for a brief 
period) into Kildale, and it is worthy of note that the altitude 
is almost the same as that of the West Bank watershed (dividing 
Kildale from Eskdale), beneath the peat, viz., between 580 and 
550 feet. The exact level of this watershed is difficult to 
ascertain with precision, but if we accept the above channel 
as indicating a flow into Kildale and Eskdale, then the altitude 
of its floor will give us the elevation of the rocky bottom 
at West Bank, at the close of the drainage eastwards, that 
is to say 550 feet. 
Proceedings of the Cleveland Field Club, Vol. II., p. 25. 
