36 
KENDALL: J'ME GLACIER LAKES OF CLEVELANlJ. 
of 130 feet. The floor of the valley is occupied by alluvium 
<;onsisting partly of fine laminated clay and partly of sand with 
a little gravel. On the west the boundary is a faulted tract 
of Jurassic rocks in which are two gaps, one broad and flat, 
having a summit altitude at Coxwold of 225 feet, the other 
the narrow, deep gorge of the River Derwent. At the present 
time nearly the whole of the drainage of the country south of 
the Esk passes into this basin, and is diverted against the slope 
of the rocks and the grain of the country through Kirkliam 
Gorge into the Vale of York (Plate XIV.). The explanation of 
this anomalous course is as follows : — For a long time the entrance 
to the Vale of Pickering was blocked by the ice-sheet whicli left 
the present moraine at Hunmanby. A lake was formed which 
overflowed at tlie lowest point of the watershed, which was on 
the line of a little valley running past Malton. The Coxwold 
valley may have been rather higher, and, in any (;ase. at this 
time it was blocked by the Vale of York glacier. Kirkham 
Gorge having been cut down below the level of the Filey moraine 
before the retreat of the ice-sheet, the drainage of Lake Pickering 
continued to follow the same channel, and now has cut down 
the gorge to below 50 feet CD. 
A range of gravel mounds extending along Seamei- Moor 
a])j)ears to maik the extreme limit of the advance of the ice-lobe. 
Hcyond this moraine the country is free from drift. Beyond 
this ridge the steep slopes of the moorland towards the south 
are deeply trenched by dry gullies (Plate XIII.), which a])pear 
to have been ])roduced by water flowing from tlie ice-front. 
At Seamer there is an immense spi'ead of gravel, probably con- 
nected with two great gorges, Deepdale and the railway valley. 
Deepdale appears to have carried off the drainage of a small 
lakelet about Wheatcroft, on the road between Scarborough 
And Filey. Between the railway and Forge Valley several 
small valleys occur, which, after running for some distance 
from east to west, swing southward. Associated with them 
there are many intermittent gravel mounds. To the north of 
East Aj'ton, at the mouth of Forge Valle^^, and thence onward 
to Gallows Hill, between Wykeham and Brompton, extends a 
great gravel bench which has a breadth of from a quarter to half 
