KENDALL : THE fiLACIEK LAKES OF CLEVELAND. 
17 
at its maximum, reached the 725-foot contour (Fig. .3). 
This lake was formed by a lobe of ice which pushed over the 
MAP OF THE ESKDALE SYSTEM OF LAKES AT THE LEVELS CORUESPON DIN<; 
WITH THE LADY BRIDGE SLACK AND MOSS SWANC OVERFLOWS. 
northern watershed and dammed Eskdale at Lealholm, laying 
down a moraine entirely across tlie valley. On the southern 
side of Eskdale drift is found up to altitudes of 700 feet, and 
a great morainic ridge, 100 feet above the valley bottom, runs 
across Glaisdale. The Egton Grange valley is also closed by 
a similar morainic barrier, and the whole formed, at the maximum 
•extension of the ice, a lake eleven miles long, not less than 400 
feet deep, and with ramifications up all the principal tributary 
valleys. These conclusions are confirmed in a very definite 
manner by a splendid series of overflow channels, which reveal 
the movements of tlie ice with great exactness. The first of 
these is a great trench, deepening and falling towards the south, 
which cuts across the edge of Murk-Mire Moor (Plate VI.). The 
sill of the intake is at 714 feet, and the channel extends for a 
mile and a half as a deep groove of characteristic section, filled 
with moss and swamp. After this stretch of complete trough 
the channel is continued for another mile to Hazel Head by 
B 
