132 Tue Lower Nivu. 
buried river valley 300 feet below sea level. Another bore 
near Barrow-in-Furness gives a depth of 450 feet before the 
bed of the old valley is touched. The pre-glacial valley of 
the Mersey is 160 feet deep. At Bo’ness, on the river Forth, 
the ancient river channel is now 570 feet below present sea 
level. After the Pliocene uplift a gradual subsidence of land 
took place. It was continued into glacial times, and in this 
district reached its maximum when the shore line stood 100 
feet higher than the present sea level. Along the rocky 
headlands of Galloway the waves cut out a rock platform 
at an elevation of 100 feet, while in the estuaries a beach was 
deposited at the same elevation. About this time the glacia- 
tion of Southern Scotland was at its greatest. Galloway ice 
was travelling eastward over the Nithsdale valley. As the 
ice-fields decreased in size an elevation of land took place, 
and the shore line receded until it reached the 50 feet contour 
line. There was sufficient pause at this height to form 
another estuarine beach. During the formation of this 50 
feet beach the glaciers were greatly reduced in size. They 
were confined to valleys, and their moraine deposits on the 
outlying plains tend in the same direction as that of the 
valley from which they emerge. Since that time the eleva- 
tion of the land has been continuous, with the exception of 
a slight pause producing another marine terrace at 25 feet. 
PRE-GLACIAL NITH. 
The uplift in the Pliocene Age would enable the rivers 
to cut very deeply into the land. The goo feet gap at Black- 
wood would give some idea of the size of the valley further 
down stream. The soft sandstones of Lower Nithsdale 
would be more easily eroded, and the result would probably 
be a wide trough, but the amount of erosion would be 
greater in Caerlaverock than at Blackwood. The pre-glacial 
Nith valley must have been both large and deep. Bores 
near the mouth of the Lochar give a depth of 200 feet before 
rock is touched. The valley walls are at least three miles 
apart; they dip below the old beach of the Lochar at Bank- 
end at a sharp gradient, and point conclusively te a buried 
valley of large dimensions. No. 1 bore at the Arrol-Johnston 
