4 
KENDALL : THE GLACIER LAKES OF CLEVELAND. 
left the " rough ground " off Teesmouth as its terminal moraine. 
This movement would account for the striae near Saltburn and 
the general west-to-east transport of local material associated 
with the Lower Boulder Clay. Subsequently the advancing 
Scotch and Scandinavian ice-sheets blocked the way of the 
Western ice seawards. Weardale being filled with ice made 
a northern escape impossible, and so the Teesdale stream turned 
southwards and invaded the Vale of York. It passed over 
the Northallerton watershed, rose high against the flanks of 
the Cleveland, Hambledon, and Howardian Hills, received a great 
tributary from the Ure, and probably another from the Swale, 
and passed down the valley as far as York, in the neighbourliood 
of which it laid down two well-marked moraines. 
II. — The Xorther7i Sheet. — The ice of the Scottish Low- 
lands accumulating in the Tweed valley, instead of pursuing 
a direct course to the sea at Berwick, at one stage turned sharply 
round the projecting end of the Cheviots and took a course 
almost southwards. The pressure of the Scandinavian ice- 
sheet seems to have been the overmastering cause tliat pro- 
duced this strange deflection. This Scottish glacier, reinforced 
by Cheviot ice and the glaciers of the Tyne and Wear valleys, 
swept across Xorthumberland seawards, but was again pressed 
inland over the Durham coast, producing the Roker striations. 
III. — The Scandinavian Sheet. — A great sea of ice. originating 
in Scandinavia, seems at this time to have filled tlie North Sea 
basin, and to have begun to press strongty on our noi thern coast. 
The impact of this sheet seems to have taken place from north 
to south, the Scottish ice feeling its pressure first and being 
forced westwards over the Clyde watershed into the Irish sea. 
Then the Tweed-Cheviot stream was diverted inland, and pressure 
was brought to bear on the Teesdale glacier. By this progressive 
movement southwards the Scotch-Cheviot ice was pressed in 
upon the northern face of Cleveland, the Tees ice-stream was 
diverted into the Vale of York, and the great mass of western 
boulders deposited off Teesmouth was spread down the York- 
shire coast mixed with Scottish and Scandinavian erratics. 
This route is indicated by the consistent series of striae observed 
along the Yorkshire coast. 
