496 | MR. P. F. KENDALL ON A SYSTEM OF [ Aug. 1902, 
Range a great overflow took place by the Pass of Stainmoor, at 
altitudes ranging from 1435 feet (the lower pass) to 1800 near 
Roman Fell. This latter glacier entered Teesdale just below 
Middleton, where (as I am informed by Mr. Dwerryhouse) it was 
joined by a native glacier having its source in Upper Teesdale. It 
was charged with igneous rocks from the Lake District, most notable 
of which is the Shap Granite. This glacier made its way down 
into the low grounds, where it seems to have deployed considerably, 
and it reached the sea-coast, which was probably not very far 
distant from its present position. How far the glacier extended 
seaward has not been, and I think probably never will be, definitely 
ascertained ; but a belt of very rough sea-bottom, known to fishermen 
as the ‘Rough Ground,’ strewn with large boulders, among which 
are many of Shap Granite, lies a few miles off the mouth of the 
Tees, and this was interpreted by Carvill Lewis as the moraine. 
It is not to be supposed, however, that the boulders of Shap 
Granite were in all cases borne to their ultimate resting-place by 
the ice of the Teesdale Glacier—they are scattered right down the 
coast of Yorkshire, and even into Lincolnshire; and it seems to me 
most probable that those at least which are found to the southward 
of Robin Hood’s Bay were carried by a later ice-movement. The 
advance of the Teesdale Glacier I believe to have effected the 
grooving of the rocks at Hob Hill described by Mr. Barrow (see 
p. 494), and the general west-to-east transport of local material 
associated with the Lower Boulder-Clay. 
At some stage of the Glacial Period, the advance of the Scandi- 
navian ice-sheet barred the access of the Teesdale Glacier to the 
coast-line—whether at an early or a late stage will be discussed 
subsequently ; and the Teesdale Glacier was compelled to turn from 
its direct seaward path. ‘Two courses lay before it—to turn north- 
ward into the Wear Valley, or southward into the Vale of York. 
The northerly route was preoccupied, however, by the native Wear- 
dale Glacier, which was perhaps already much encumbered by the 
pressure of the Tyne Glacier on the north, and consequently the 
route down the Vale of York was adopted. The watershed, which 
in pre-Glacial times separated the Tees drainage from the Ouse, was 
a very low one,’ lying about on a line joining Bedale with Northal- 
lerton, where the Drift is now very thin, and over this the glacier 
passed. It received a great tributary from the Ure Valley, and 
possibly one from the Valley of the Swale, but I am rather disposed 
to agree with Carvill Lewis in thinking that Lower Swaledale was 
not occupied by a glacier. The western edge of the Teesdale 
Glacier, where it swept over into the Vale of York, surmounted hills 
600 feet above sea-level, and may be presumed to have been of 
greater altitude. It stretched down to Escrick, where it left a 
splendid terminal moraine, and a second terminal moraine spans 
the Vale at the city of York itself. 
1 There was no doubt a very great sub-glacial denudation of the soft Triassic 
sandstone, but no attempt can be made to evaluate it. I think, however, that 
no material change was made by it in the position of this watershed. 
