606 MR. A. R. DWERRYHOUSE ON THE GLACIATION OF [ Aug. 1902, 
(6) Phenomena during the Period of Retreat. 
As the ice dwindled in the valley of the South Tyne, a marked 
effect was produced upon the series of lakes along its southern 
margin. This I have already described under the heading of 
Glacial Lakes (p. 602). At the same time, the diminished supply 
of ice from the Solway area allowed the North-Tyne Glacier to 
resume its normal south-easterly course. 
V. GenerRAL ConcoLusIons. 
(1) Upper Teesdale was heavily glaciated by ice formed in the 
upper parts of the Dale, and on the eastern slope of the Cross-Fell 
range. 
(i) This part of the Dale was never invaded by ice from 
the Lrish-Sea area. 
(iii) At no time during the Glacial Period. was this district 
completely buried by ice, but the higher peaks stood out as ‘nuna- 
takkr’ from the surrounding glaciers, : 
(iv) At the period of maximum glaciation a number of lakes 
were formed, owing to the obstruction of the drainage of lateral 
tributary-valleys by the ice of the main glaciers. 
(v) Lunedale was occupied by ice which came over from the 
drainage-basin of the Irish Sea. In the neighbourhood of 
Middleton-in-Teesdale this stream of ice became confluent with 
the Teesdale Glacier, and then the joint stream flowed on towards 
Barnard Castle. 
(vi) The ice of Teesdale was deflected by the thrust of the 
Stainmoor Glacier and caused to flow over into the valley of the 
Wear, where it became confluent with the Weardale Glacier in 
the neighbourhood of Wear-Valley Junction. 
(vii) During the period of retreat of the ice there was a long 
interval, in the course of which it remained at a constant level, 
producing well-marked drainage-channels. 
(viii) After this interval of constant level the ice was removed 
from the country with great rapidity. 
(ix) A tongue of ice flowed from Upper Teesdale, by way of Yad 
Moss, into the valley of the South Tyne. 
(x) Weardale and its tributary valleys above Witton-le-Wear | 
were heavily glaciated by ice formed within the drainage-basin of 
the Wear, but this part of the Dale was never invaded by ice 
from outside. 
(xi) The ice which passed over from the head of Teesdale into 
the Valley of the South Tyne, there formed a glacier which stood 
at a level of about 1800 feet to the south of the village of Alston, 
and was joined at that place by a glacier which flowed westward 
down the Valley of the Nent. 
(xii) A large glacier flowed across the northern end of the 
Pennine Chain in an easterly direction, becoming confluent with 
that of Alstondale in the neighbourhood of Lambley. This 
