408 
GRACE : THE GLACIAL GEOLOGY OF FURXESS. 
ice that it was diverted to the south-west and kept along the fell side 
until it reached the part of the fell which falls from over 1000 feet to 
700 feet, when it turned almost westwards, and passed back into the 
Duddon Valley, or rather, across its mouth. The interpretation of 
the evidence near the mouth of the Duddon is difficult, and the stream 
of ice westwards may belong to a later phase. 
The glacier associated with the Coniston Basin was the largest in 
Furness. Its ramifications may be seen on the map. The whole of 
the Fells at the head of the basin are glaciated from the north, the 
evidence extending westwards up the slopes of Wetherlam to over 
2000 feet and eastwards beyond the limits of our area. A number of 
deeply cut channels converge towards the Coniston Basin, and near 
High Cross are several large erratics of Ordovician Ash. The amphi- 
theatre at the head of the lake is deeply scored by valleys, and at the 
bottom of the slope, near the north-east corner of the lake, is an area 
covered with drift-like hummocks. Besides this compHcated series of 
minor valleys, the chief feeders into the basin during the definite 
valley stage would be the Church Beck Valley and Yewdale. 
There are many features in the Church Beck Valley which must 
be regarded as due to the abnormal erosion of the Glacial Period. The 
general appearance of its head is that of a large and somewhat irregular 
amphitheatre into which three hanging valleys open. The most 
westerly of these is the highest, and also the least. It is a well de- 
veloped combe, which holds Low Water at a level of 1786 feet, and is 
drained by a stream which falls from 1700 feet precipitously to below 
1200 feet, so that the combe hangs almost 600 feet above the valley. 
The middle valley holds Levers Water (1350 feet), and is longer, and 
shews signs of glaciation. It is probable that the wide portion near 
the tarn with its vertical rocky sides is due entirely to ice action. 
Here again there is a rapid fall from the level of the upper valley to 
that of the main valley, and the stream descends in a series of cascades 
The Red Dell, on the other hand, gives less evidence of glacial action 
being V-shaped, except near its mouth where there are large areas of 
rounded and polished rock, and the valley becomes more U-shaped. 
This also hangs in relation to the main valley. The stretch of valley 
from the Copper Mines to the bridge is strikingly level, and traces of 
the same floor may be found further down, but at the bridge the stream 
plunges to the bottom of a V-shaped valley which has been cut into 
the floor of a wider one. 
