8 
KENDALL : THE GLACIER LAKES OF CLEVELAND. 
to form a lake. This lake may find an escape, either through 
or over the ice, in which case the onh^ records of the lake on the 
retreat of the glacier will be beaches, deltas, or lacustrine deposits. 
But if tlie lake drain by an overflow across a col, or spur, the 
water will cut a channel, which will remain a permanent record 
of the lake after the retreat of the ice- barrier. Such an overflow 
channel may be either " anomalous " or " deserted." If the 
ice-dam persist for a sufficient length of time, or if a moraine of 
sufficient height be left, the excavation of this notch will continue 
until the lake be completely drained, and the channel will carry 
the normal drainage of the countr3^ There will then be left 
an anomalous gorge disproportionately narrow for the stream it 
contains, whilst tlie original line of^ drainage below the moraine 
Fig. 2. 
SECTION AT DANBY BRICK AM) TIJ.E WOKKS. 
is left as a deserted valley. Such a gorge is that of the River 
Nidd, near Knaresborough. If, however, on the retreat of the 
ice, the old line of drainage is resumed, the temporary overflow 
channel will be abandoned, and thereafter will carry only such 
small amount of drainage as belongs to its own very limited 
catchment, sometimes none at all. Then we shall have a deserted 
overflow channel. 
